Restore Graceful Restarting & Socket Activation (#7274)

* Prevent deadlock in indexer initialisation during graceful restart

* Move from gracehttp to our own service to add graceful ssh

* Add timeout for start of indexers and make hammer time configurable

* Fix issue with re-initialization in indexer during tests

* move the code to detect use of closed to graceful

* Handle logs gracefully - add a pid suffix just before restart

* Move to using a cond and a holder for indexers

* use time.Since

* Add some comments and attribution

* update modules.txt

* Use zero to disable timeout

* Move RestartProcess to its own file

* Add cleanup routine

45 files changed, 1199 insertions, 2006 deletions

diff --git a/cmd/web.go b/cmd/web.go
index 9a5ce5d2b6..ae05b9e145 100644
--- a/cmd/web.go
+++ b/cmd/web.go
@@ -75,17 +75,13 @@ func runLetsEncrypt(listenAddr, domain, directory, email string, m http.Handler)
 	}
 	go func() {
 		log.Info("Running Let's Encrypt handler on %s", setting.HTTPAddr+":"+setting.PortToRedirect)
-		var err = http.ListenAndServe(setting.HTTPAddr+":"+setting.PortToRedirect, certManager.HTTPHandler(http.HandlerFunc(runLetsEncryptFallbackHandler))) // all traffic coming into HTTP will be redirect to HTTPS automatically (LE HTTP-01 validation happens here)
+		// all traffic coming into HTTP will be redirect to HTTPS automatically (LE HTTP-01 validation happens here)
+		var err = runHTTP(setting.HTTPAddr+":"+setting.PortToRedirect, certManager.HTTPHandler(http.HandlerFunc(runLetsEncryptFallbackHandler)))
 		if err != nil {
 			log.Fatal("Failed to start the Let's Encrypt handler on port %s: %v", setting.PortToRedirect, err)
 		}
 	}()
-	server := &http.Server{
-		Addr:      listenAddr,
-		Handler:   m,
-		TLSConfig: certManager.TLSConfig(),
-	}
-	return server.ListenAndServeTLS("", "")
+	return runHTTPSWithTLSConfig(listenAddr, certManager.TLSConfig(), context2.ClearHandler(m))
 }
 
 func runLetsEncryptFallbackHandler(w http.ResponseWriter, r *http.Request) {
@@ -101,12 +97,21 @@ func runLetsEncryptFallbackHandler(w http.ResponseWriter, r *http.Request) {
 }
 
 func runWeb(ctx *cli.Context) error {
+	if os.Getppid() > 1 && len(os.Getenv("LISTEN_FDS")) > 0 {
+		log.Info("Restarting Gitea on PID: %d from parent PID: %d", os.Getpid(), os.Getppid())
+	} else {
+		log.Info("Starting Gitea on PID: %d", os.Getpid())
+	}
+
+	// Set pid file setting
 	if ctx.IsSet("pid") {
 		setting.CustomPID = ctx.String("pid")
 	}
 
+	// Perform global initialization
 	routers.GlobalInit()
 
+	// Set up Macaron
 	m := routes.NewMacaron()
 	routes.RegisterRoutes(m)
 
@@ -164,6 +169,7 @@ func runWeb(ctx *cli.Context) error {
 	var err error
 	switch setting.Protocol {
 	case setting.HTTP:
+		NoHTTPRedirector()
 		err = runHTTP(listenAddr, context2.ClearHandler(m))
 	case setting.HTTPS:
 		if setting.EnableLetsEncrypt {
@@ -172,9 +178,15 @@ func runWeb(ctx *cli.Context) error {
 		}
 		if setting.RedirectOtherPort {
 			go runHTTPRedirector()
+		} else {
+			NoHTTPRedirector()
 		}
 		err = runHTTPS(listenAddr, setting.CertFile, setting.KeyFile, context2.ClearHandler(m))
 	case setting.FCGI:
+		NoHTTPRedirector()
+		// FCGI listeners are provided as stdin - this is orthogonal to the LISTEN_FDS approach
+		// in graceful and systemD
+		NoMainListener()
 		var listener net.Listener
 		listener, err = net.Listen("tcp", listenAddr)
 		if err != nil {
@@ -187,6 +199,10 @@ func runWeb(ctx *cli.Context) error {
 		}()
 		err = fcgi.Serve(listener, context2.ClearHandler(m))
 	case setting.UnixSocket:
+		// This could potentially be inherited using LISTEN_FDS but currently
+		// these cannot be inherited
+		NoHTTPRedirector()
+		NoMainListener()
 		if err := os.Remove(listenAddr); err != nil && !os.IsNotExist(err) {
 			log.Fatal("Failed to remove unix socket directory %s: %v", listenAddr, err)
 		}
@@ -207,8 +223,9 @@ func runWeb(ctx *cli.Context) error {
 	}
 
 	if err != nil {
-		log.Fatal("Failed to start server: %v", err)
+		log.Critical("Failed to start server: %v", err)
 	}
-
+	log.Info("HTTP Listener: %s Closed", listenAddr)
+	log.Close()
 	return nil
 }
diff --git a/cmd/web_graceful.go b/cmd/web_graceful.go
index 53f407ce9e..07b5a964c5 100644
--- a/cmd/web_graceful.go
+++ b/cmd/web_graceful.go
@@ -10,36 +10,28 @@ import (
 	"crypto/tls"
 	"net/http"
 
-	"code.gitea.io/gitea/modules/log"
-
-	"github.com/facebookgo/grace/gracehttp"
+	"code.gitea.io/gitea/modules/graceful"
 )
 
 func runHTTP(listenAddr string, m http.Handler) error {
-	return gracehttp.Serve(&http.Server{
-		Addr:    listenAddr,
-		Handler: m,
-	})
+	return graceful.HTTPListenAndServe("tcp", listenAddr, m)
 }
 
 func runHTTPS(listenAddr, certFile, keyFile string, m http.Handler) error {
-	config := &tls.Config{
-		MinVersion: tls.VersionTLS10,
-	}
-	if config.NextProtos == nil {
-		config.NextProtos = []string{"http/1.1"}
-	}
-
-	config.Certificates = make([]tls.Certificate, 1)
-	var err error
-	config.Certificates[0], err = tls.LoadX509KeyPair(certFile, keyFile)
-	if err != nil {
-		log.Fatal("Failed to load https cert file %s: %v", listenAddr, err)
-	}
-
-	return gracehttp.Serve(&http.Server{
-		Addr:      listenAddr,
-		Handler:   m,
-		TLSConfig: config,
-	})
+	return graceful.HTTPListenAndServeTLS("tcp", listenAddr, certFile, keyFile, m)
+}
+
+func runHTTPSWithTLSConfig(listenAddr string, tlsConfig *tls.Config, m http.Handler) error {
+	return graceful.HTTPListenAndServeTLSConfig("tcp", listenAddr, tlsConfig, m)
+}
+
+// NoHTTPRedirector tells our cleanup routine that we will not be using a fallback http redirector
+func NoHTTPRedirector() {
+	graceful.InformCleanup()
+}
+
+// NoMainListener tells our cleanup routine that we will not be using a possibly provided listener
+// for our main HTTP/HTTPS service
+func NoMainListener() {
+	graceful.InformCleanup()
 }
diff --git a/cmd/web_windows.go b/cmd/web_windows.go
index 0fc6cbea0d..cdd2cc513b 100644
--- a/cmd/web_windows.go
+++ b/cmd/web_windows.go
@@ -7,6 +7,7 @@
 package cmd
 
 import (
+	"crypto/tls"
 	"net/http"
 )
 
@@ -17,3 +18,20 @@ func runHTTP(listenAddr string, m http.Handler) error {
 func runHTTPS(listenAddr, certFile, keyFile string, m http.Handler) error {
 	return http.ListenAndServeTLS(listenAddr, certFile, keyFile, m)
 }
+
+func runHTTPSWithTLSConfig(listenAddr string, tlsConfig *tls.Config, m http.Handler) error {
+	server := &http.Server{
+		Addr:      listenAddr,
+		Handler:   m,
+		TLSConfig: tlsConfig,
+	}
+	return server.ListenAndServeTLS("", "")
+}
+
+// NoHTTPRedirector is a no-op on Windows
+func NoHTTPRedirector() {
+}
+
+// NoMainListener is a no-op on Windows
+func NoMainListener() {
+}
diff --git a/custom/conf/app.ini.sample b/custom/conf/app.ini.sample
index 5ee2162ba3..08a2c8e32f 100644
--- a/custom/conf/app.ini.sample
+++ b/custom/conf/app.ini.sample
@@ -244,6 +244,12 @@ LFS_CONTENT_PATH = data/lfs
 LFS_JWT_SECRET =
 ; LFS authentication validity period (in time.Duration), pushes taking longer than this may fail.
 LFS_HTTP_AUTH_EXPIRY = 20m
+; Allow graceful restarts using SIGHUP to fork
+ALLOW_GRACEFUL_RESTARTS = true
+; After a restart the parent will finish ongoing requests before
+; shutting down. Force shutdown if this process takes longer than this delay.
+; set to a negative value to disable
+GRACEFUL_HAMMER_TIME = 60s
 ; Static resources, includes resources on custom/, public/ and all uploaded avatars web browser cache time, default is 6h
 STATIC_CACHE_TIME = 6h
 
@@ -299,6 +305,9 @@ ISSUE_INDEXER_QUEUE_DIR = indexers/issues.queue
 ISSUE_INDEXER_QUEUE_CONN_STR = "addrs=127.0.0.1:6379 db=0"
 ; Batch queue number, default is 20
 ISSUE_INDEXER_QUEUE_BATCH_NUMBER = 20
+; Timeout the indexer if it takes longer than this to start.
+; Set to zero to disable timeout.
+STARTUP_TIMEOUT=30s
 
 ; repo indexer by default disabled, since it uses a lot of disk space
 REPO_INDEXER_ENABLED = false
diff --git a/docs/content/doc/advanced/config-cheat-sheet.en-us.md b/docs/content/doc/advanced/config-cheat-sheet.en-us.md
index 29a971da12..6fb92f2721 100644
--- a/docs/content/doc/advanced/config-cheat-sheet.en-us.md
+++ b/docs/content/doc/advanced/config-cheat-sheet.en-us.md
@@ -157,6 +157,8 @@ Values containing `#` or `;` must be quoted using `` ` `` or `"""`.
 - `LETSENCRYPT_ACCEPTTOS`: **false**: This is an explicit check that you accept the terms of service for Let's Encrypt.
 - `LETSENCRYPT_DIRECTORY`: **https**: Directory that Letsencrypt will use to cache information such as certs and private keys.
 - `LETSENCRYPT_EMAIL`: **email@example.com**: Email used by Letsencrypt to notify about problems with issued certificates. (No default)
+- `ALLOW_GRACEFUL_RESTARTS`: **true**: Perform a graceful restart on SIGHUP
+- `GRACEFUL_HAMMER_TIME`: **60s**: After a restart the parent process will stop accepting new connections and will allow requests to finish before stopping. Shutdown will be forced if it takes longer than this time.
 
 ## Database (`database`)
 
@@ -189,6 +191,7 @@ Values containing `#` or `;` must be quoted using `` ` `` or `"""`.
 - `REPO_INDEXER_EXCLUDE`: **empty**: A comma separated list of glob patterns (see https://github.com/gobwas/glob) to **exclude** from the index. Files that match this list will not be indexed, even if they match in `REPO_INDEXER_INCLUDE`.
 - `UPDATE_BUFFER_LEN`: **20**: Buffer length of index request.
 - `MAX_FILE_SIZE`: **1048576**: Maximum size in bytes of files to be indexed.
+- `STARTUP_TIMEOUT`: **30s**: If the indexer takes longer than this timeout to start - fail. (This timeout will be added to the hammer time above for child processes - as bleve will not start until the previous parent is shutdown.) Set to zero to never timeout.
 
 ## Admin (`admin`)
 - `DEFAULT_EMAIL_NOTIFICATIONS`: **enabled**: Default configuration for email notifications for users (user configurable). Options: enabled, onmention, disabled
diff --git a/go.mod b/go.mod
index 203b6ce4c1..9183ad3469 100644
--- a/go.mod
+++ b/go.mod
@@ -32,13 +32,8 @@ require (
 	github.com/emirpasic/gods v1.12.0
 	github.com/etcd-io/bbolt v1.3.2 // indirect
 	github.com/ethantkoenig/rupture v0.0.0-20180203182544-0a76f03a811a
-	github.com/facebookgo/clock v0.0.0-20150410010913-600d898af40a // indirect
 	github.com/facebookgo/ensure v0.0.0-20160127193407-b4ab57deab51 // indirect
-	github.com/facebookgo/freeport v0.0.0-20150612182905-d4adf43b75b9 // indirect
-	github.com/facebookgo/grace v0.0.0-20160926231715-5729e484473f
-	github.com/facebookgo/httpdown v0.0.0-20160323221027-a3b1354551a2 // indirect
 	github.com/facebookgo/stack v0.0.0-20160209184415-751773369052 // indirect
-	github.com/facebookgo/stats v0.0.0-20151006221625-1b76add642e4 // indirect
 	github.com/facebookgo/subset v0.0.0-20150612182917-8dac2c3c4870 // indirect
 	github.com/gliderlabs/ssh v0.2.2
 	github.com/glycerine/go-unsnap-stream v0.0.0-20180323001048-9f0cb55181dd // indirect
diff --git a/go.sum b/go.sum
index 7306966800..8bdc6b803a 100644
--- a/go.sum
+++ b/go.sum
@@ -142,20 +142,10 @@ github.com/etcd-io/bbolt v1.3.2 h1:RLRQ0TKLX7DlBRXAJHvbmXL17Q3KNnTBtZ9B6Qo+/Y0=
 github.com/etcd-io/bbolt v1.3.2/go.mod h1:ZF2nL25h33cCyBtcyWeZ2/I3HQOfTP+0PIEvHjkjCrw=
 github.com/ethantkoenig/rupture v0.0.0-20180203182544-0a76f03a811a h1:M1bRpaZAn4GSsqu3hdK2R8H0AH9O6vqCTCbm2oAFGfE=
 github.com/ethantkoenig/rupture v0.0.0-20180203182544-0a76f03a811a/go.mod h1:MkKY/CB98aVE4VxO63X5vTQKUgcn+3XP15LMASe3lYs=
-github.com/facebookgo/clock v0.0.0-20150410010913-600d898af40a h1:yDWHCSQ40h88yih2JAcL6Ls/kVkSE8GFACTGVnMPruw=
-github.com/facebookgo/clock v0.0.0-20150410010913-600d898af40a/go.mod h1:7Ga40egUymuWXxAe151lTNnCv97MddSOVsjpPPkityA=
 github.com/facebookgo/ensure v0.0.0-20160127193407-b4ab57deab51 h1:0JZ+dUmQeA8IIVUMzysrX4/AKuQwWhV2dYQuPZdvdSQ=
 github.com/facebookgo/ensure v0.0.0-20160127193407-b4ab57deab51/go.mod h1:Yg+htXGokKKdzcwhuNDwVvN+uBxDGXJ7G/VN1d8fa64=
-github.com/facebookgo/freeport v0.0.0-20150612182905-d4adf43b75b9 h1:wWke/RUCl7VRjQhwPlR/v0glZXNYzBHdNUzf/Am2Nmg=
-github.com/facebookgo/freeport v0.0.0-20150612182905-d4adf43b75b9/go.mod h1:uPmAp6Sws4L7+Q/OokbWDAK1ibXYhB3PXFP1kol5hPg=
-github.com/facebookgo/grace v0.0.0-20160926231715-5729e484473f h1:0mlfEUWnUDVZnqWEVHGerL5bKYDKMEmT/Qk/W/3nGuo=
-github.com/facebookgo/grace v0.0.0-20160926231715-5729e484473f/go.mod h1:KigFdumBXUPSwzLDbeuzyt0elrL7+CP7TKuhrhT4bcU=
-github.com/facebookgo/httpdown v0.0.0-20160323221027-a3b1354551a2 h1:3Zvf9wRhl1cOhckN1oRGWPOkIhOketmEcrQ4TeFAoR4=
-github.com/facebookgo/httpdown v0.0.0-20160323221027-a3b1354551a2/go.mod h1:TUV/fX3XrTtBQb5+ttSUJzcFgLNpILONFTKmBuk5RSw=
 github.com/facebookgo/stack v0.0.0-20160209184415-751773369052 h1:JWuenKqqX8nojtoVVWjGfOF9635RETekkoH6Cc9SX0A=
 github.com/facebookgo/stack v0.0.0-20160209184415-751773369052/go.mod h1:UbMTZqLaRiH3MsBH8va0n7s1pQYcu3uTb8G4tygF4Zg=
-github.com/facebookgo/stats v0.0.0-20151006221625-1b76add642e4 h1:0YtRCqIZs2+Tz49QuH6cJVw/IFqzo39gEqZ0iYLxD2M=
-github.com/facebookgo/stats v0.0.0-20151006221625-1b76add642e4/go.mod h1:vsJz7uE339KUCpBXx3JAJzSRH7Uk4iGGyJzR529qDIA=
 github.com/facebookgo/subset v0.0.0-20150612182917-8dac2c3c4870 h1:E2s37DuLxFhQDg5gKsWoLBOB0n+ZW8s599zru8FJ2/Y=
 github.com/facebookgo/subset v0.0.0-20150612182917-8dac2c3c4870/go.mod h1:5tD+neXqOorC30/tWg0LCSkrqj/AR6gu8yY8/fpw1q0=
 github.com/flynn/go-shlex v0.0.0-20150515145356-3f9db97f8568 h1:BHsljHzVlRcyQhjrss6TZTdY2VfCqZPbv5k3iBFa2ZQ=
diff --git a/models/repo_indexer.go b/models/repo_indexer.go
index b842a1c87f..9cc002a8ab 100644
--- a/models/repo_indexer.go
+++ b/models/repo_indexer.go
@@ -8,10 +8,12 @@ import (
 	"fmt"
 	"strconv"
 	"strings"
+	"time"
 
 	"code.gitea.io/gitea/modules/base"
 	"code.gitea.io/gitea/modules/charset"
 	"code.gitea.io/gitea/modules/git"
+	"code.gitea.io/gitea/modules/graceful"
 	"code.gitea.io/gitea/modules/indexer"
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/setting"
@@ -70,9 +72,30 @@ func InitRepoIndexer() {
 	if !setting.Indexer.RepoIndexerEnabled {
 		return
 	}
+	waitChannel := make(chan time.Duration)
 	repoIndexerOperationQueue = make(chan repoIndexerOperation, setting.Indexer.UpdateQueueLength)
-	indexer.InitRepoIndexer(populateRepoIndexerAsynchronously)
-	go processRepoIndexerOperationQueue()
+	go func() {
+		start := time.Now()
+		log.Info("Initializing Repository Indexer")
+		indexer.InitRepoIndexer(populateRepoIndexerAsynchronously)
+		go processRepoIndexerOperationQueue()
+		waitChannel <- time.Since(start)
+	}()
+	if setting.Indexer.StartupTimeout > 0 {
+		go func() {
+			timeout := setting.Indexer.StartupTimeout
+			if graceful.IsChild && setting.GracefulHammerTime > 0 {
+				timeout += setting.GracefulHammerTime
+			}
+			select {
+			case duration := <-waitChannel:
+				log.Info("Repository Indexer Initialization took %v", duration)
+			case <-time.After(timeout):
+				log.Fatal("Repository Indexer Initialization Timed-Out after: %v", timeout)
+			}
+		}()
+
+	}
 }
 
 // populateRepoIndexerAsynchronously asynchronously populates the repo indexer
diff --git a/modules/graceful/cleanup.go b/modules/graceful/cleanup.go
new file mode 100644
index 0000000000..1de087a999
--- /dev/null
+++ b/modules/graceful/cleanup.go
@@ -0,0 +1,38 @@
+// Copyright 2019 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package graceful
+
+import "sync"
+
+var cleanupWaitGroup sync.WaitGroup
+
+func init() {
+	cleanupWaitGroup = sync.WaitGroup{}
+
+	// There are three places that could inherit sockets:
+	//
+	// * HTTP or HTTPS main listener
+	// * HTTP redirection fallback
+	// * SSH
+	//
+	// If you add an additional place you must increment this number
+	// and add a function to call InformCleanup if it's not going to be used
+	cleanupWaitGroup.Add(3)
+
+	// Wait till we're done getting all of the listeners and then close
+	// the unused ones
+	go func() {
+		cleanupWaitGroup.Wait()
+		// Ignore the error here there's not much we can do with it
+		// They're logged in the CloseProvidedListeners function
+		_ = CloseProvidedListeners()
+	}()
+}
+
+// InformCleanup tells the cleanup wait group that we have either taken a listener
+// or will not be taking a listener
+func InformCleanup() {
+	cleanupWaitGroup.Done()
+}
diff --git a/modules/graceful/net.go b/modules/graceful/net.go
new file mode 100644
index 0000000000..f2612e21be
--- /dev/null
+++ b/modules/graceful/net.go
@@ -0,0 +1,209 @@
+// Copyright 2019 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+// This code is heavily inspired by the archived gofacebook/gracenet/net.go handler
+
+package graceful
+
+import (
+	"fmt"
+	"net"
+	"os"
+	"strconv"
+	"strings"
+	"sync"
+
+	"code.gitea.io/gitea/modules/log"
+)
+
+const (
+	listenFDs = "LISTEN_FDS"
+	startFD   = 3
+)
+
+// In order to keep the working directory the same as when we started we record
+// it at startup.
+var originalWD, _ = os.Getwd()
+
+var (
+	once  = sync.Once{}
+	mutex = sync.Mutex{}
+
+	providedListeners = []net.Listener{}
+	activeListeners   = []net.Listener{}
+)
+
+func getProvidedFDs() (savedErr error) {
+	// Only inherit the provided FDS once but we will save the error so that repeated calls to this function will return the same error
+	once.Do(func() {
+		mutex.Lock()
+		defer mutex.Unlock()
+
+		numFDs := os.Getenv(listenFDs)
+		if numFDs == "" {
+			return
+		}
+		n, err := strconv.Atoi(numFDs)
+		if err != nil {
+			savedErr = fmt.Errorf("%s is not a number: %s. Err: %v", listenFDs, numFDs, err)
+			return
+		}
+
+		for i := startFD; i < n+startFD; i++ {
+			file := os.NewFile(uintptr(i), fmt.Sprintf("listener_FD%d", i))
+
+			l, err := net.FileListener(file)
+			if err == nil {
+				// Close the inherited file if it's a listener
+				if err = file.Close(); err != nil {
+					savedErr = fmt.Errorf("error closing provided socket fd %d: %s", i, err)
+					return
+				}
+				providedListeners = append(providedListeners, l)
+				continue
+			}
+
+			// If needed we can handle packetconns here.
+			savedErr = fmt.Errorf("Error getting provided socket fd %d: %v", i, err)
+			return
+		}
+	})
+	return savedErr
+}
+
+// CloseProvidedListeners closes all unused provided listeners.
+func CloseProvidedListeners() error {
+	mutex.Lock()
+	defer mutex.Unlock()
+	var returnableError error
+	for _, l := range providedListeners {
+		err := l.Close()
+		if err != nil {
+			log.Error("Error in closing unused provided listener: %v", err)
+			if returnableError != nil {
+				returnableError = fmt.Errorf("%v & %v", returnableError, err)
+			} else {
+				returnableError = err
+			}
+		}
+	}
+	providedListeners = []net.Listener{}
+
+	return returnableError
+}
+
+// GetListener obtains a listener for the local network address. The network must be
+// a stream-oriented network: "tcp", "tcp4", "tcp6", "unix" or "unixpacket". It
+// returns an provided net.Listener for the matching network and address, or
+// creates a new one using net.Listen.
+func GetListener(network, address string) (net.Listener, error) {
+	// Add a deferral to say that we've tried to grab a listener
+	defer InformCleanup()
+	switch network {
+	case "tcp", "tcp4", "tcp6":
+		tcpAddr, err := net.ResolveTCPAddr(network, address)
+		if err != nil {
+			return nil, err
+		}
+		return GetListenerTCP(network, tcpAddr)
+	case "unix", "unixpacket":
+		unixAddr, err := net.ResolveUnixAddr(network, address)
+		if err != nil {
+			return nil, err
+		}
+		return GetListenerUnix(network, unixAddr)
+	default:
+		return nil, net.UnknownNetworkError(network)
+	}
+}
+
+// GetListenerTCP announces on the local network address. The network must be:
+// "tcp", "tcp4" or "tcp6". It returns a provided net.Listener for the
+// matching network and address, or creates a new one using net.ListenTCP.
+func GetListenerTCP(network string, address *net.TCPAddr) (*net.TCPListener, error) {
+	if err := getProvidedFDs(); err != nil {
+		return nil, err
+	}
+
+	mutex.Lock()
+	defer mutex.Unlock()
+
+	// look for a provided listener
+	for i, l := range providedListeners {
+		if isSameAddr(l.Addr(), address) {
+			providedListeners = append(providedListeners[:i], providedListeners[i+1:]...)
+
+			activeListeners = append(activeListeners, l)
+			return l.(*net.TCPListener), nil
+		}
+	}
+
+	// no provided listener for this address -> make a fresh listener
+	l, err := net.ListenTCP(network, address)
+	if err != nil {
+		return nil, err
+	}
+	activeListeners = append(activeListeners, l)
+	return l, nil
+}
+
+// GetListenerUnix announces on the local network address. The network must be:
+// "unix" or "unixpacket". It returns a provided net.Listener for the
+// matching network and address, or creates a new one using net.ListenUnix.
+func GetListenerUnix(network string, address *net.UnixAddr) (*net.UnixListener, error) {
+	if err := getProvidedFDs(); err != nil {
+		return nil, err
+	}
+
+	mutex.Lock()
+	defer mutex.Unlock()
+
+	// look for a provided listener
+	for i, l := range providedListeners {
+		if isSameAddr(l.Addr(), address) {
+			providedListeners = append(providedListeners[:i], providedListeners[i+1:]...)
+			activeListeners = append(activeListeners, l)
+			return l.(*net.UnixListener), nil
+		}
+	}
+
+	// make a fresh listener
+	l, err := net.ListenUnix(network, address)
+	if err != nil {
+		return nil, err
+	}
+	activeListeners = append(activeListeners, l)
+	return l, nil
+}
+
+func isSameAddr(a1, a2 net.Addr) bool {
+	// If the addresses are not on the same network fail.
+	if a1.Network() != a2.Network() {
+		return false
+	}
+
+	// If the two addresses have the same string representation they're equal
+	a1s := a1.String()
+	a2s := a2.String()
+	if a1s == a2s {
+		return true
+	}
+
+	// This allows for ipv6 vs ipv4 local addresses to compare as equal. This
+	// scenario is common when listening on localhost.
+	const ipv6prefix = "[::]"
+	a1s = strings.TrimPrefix(a1s, ipv6prefix)
+	a2s = strings.TrimPrefix(a2s, ipv6prefix)
+	const ipv4prefix = "0.0.0.0"
+	a1s = strings.TrimPrefix(a1s, ipv4prefix)
+	a2s = strings.TrimPrefix(a2s, ipv4prefix)
+	return a1s == a2s
+}
+
+func getActiveListeners() []net.Listener {
+	mutex.Lock()
+	defer mutex.Unlock()
+	listeners := make([]net.Listener, len(activeListeners))
+	copy(listeners, activeListeners)
+	return listeners
+}
diff --git a/modules/graceful/restart.go b/modules/graceful/restart.go
new file mode 100644
index 0000000000..33b3c4d417
--- /dev/null
+++ b/modules/graceful/restart.go
@@ -0,0 +1,67 @@
+// Copyright 2019 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+// This code is heavily inspired by the archived gofacebook/gracenet/net.go handler
+
+package graceful
+
+import (
+	"fmt"
+	"os"
+	"os/exec"
+	"strings"
+)
+
+// RestartProcess starts a new process passing it the active listeners. It
+// doesn't fork, but starts a new process using the same environment and
+// arguments as when it was originally started. This allows for a newly
+// deployed binary to be started. It returns the pid of the newly started
+// process when successful.
+func RestartProcess() (int, error) {
+	listeners := getActiveListeners()
+
+	// Extract the fds from the listeners.
+	files := make([]*os.File, len(listeners))
+	for i, l := range listeners {
+		var err error
+		// Now, all our listeners actually have File() functions so instead of
+		// individually casting we just use a hacky interface
+		files[i], err = l.(filer).File()
+		if err != nil {
+			return 0, err
+		}
+		// Remember to close these at the end.
+		defer files[i].Close()
+	}
+
+	// Use the original binary location. This works with symlinks such that if
+	// the file it points to has been changed we will use the updated symlink.
+	argv0, err := exec.LookPath(os.Args[0])
+	if err != nil {
+		return 0, err
+	}
+
+	// Pass on the environment and replace the old count key with the new one.
+	var env []string
+	for _, v := range os.Environ() {
+		if !strings.HasPrefix(v, listenFDs+"=") {
+			env = append(env, v)
+		}
+	}
+	env = append(env, fmt.Sprintf("%s=%d", listenFDs, len(listeners)))
+
+	allFiles := append([]*os.File{os.Stdin, os.Stdout, os.Stderr}, files...)
+	process, err := os.StartProcess(argv0, os.Args, &os.ProcAttr{
+		Dir:   originalWD,
+		Env:   env,
+		Files: allFiles,
+	})
+	if err != nil {
+		return 0, err
+	}
+	return process.Pid, nil
+}
+
+type filer interface {
+	File() (*os.File, error)
+}
diff --git a/modules/graceful/server.go b/modules/graceful/server.go
new file mode 100644
index 0000000000..efe8b264b3
--- /dev/null
+++ b/modules/graceful/server.go
@@ -0,0 +1,267 @@
+// Copyright 2019 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+// This code is highly inspired by endless go
+
+package graceful
+
+import (
+	"crypto/tls"
+	"net"
+	"os"
+	"strings"
+	"sync"
+	"syscall"
+	"time"
+
+	"code.gitea.io/gitea/modules/log"
+)
+
+type state uint8
+
+const (
+	stateInit state = iota
+	stateRunning
+	stateShuttingDown
+	stateTerminate
+)
+
+var (
+	// RWMutex for when adding servers or shutting down
+	runningServerReg sync.RWMutex
+	// ensure we only fork once
+	runningServersForked bool
+
+	// DefaultReadTimeOut default read timeout
+	DefaultReadTimeOut time.Duration
+	// DefaultWriteTimeOut default write timeout
+	DefaultWriteTimeOut time.Duration
+	// DefaultMaxHeaderBytes default max header bytes
+	DefaultMaxHeaderBytes int
+
+	// IsChild reports if we are a fork iff LISTEN_FDS is set and our parent PID is not 1
+	IsChild = len(os.Getenv(listenFDs)) > 0 && os.Getppid() > 1
+)
+
+func init() {
+	runningServerReg = sync.RWMutex{}
+
+	DefaultMaxHeaderBytes = 0 // use http.DefaultMaxHeaderBytes - which currently is 1 << 20 (1MB)
+}
+
+// ServeFunction represents a listen.Accept loop
+type ServeFunction = func(net.Listener) error
+
+// Server represents our graceful server
+type Server struct {
+	network         string
+	address         string
+	listener        net.Listener
+	PreSignalHooks  map[os.Signal][]func()
+	PostSignalHooks map[os.Signal][]func()
+	wg              sync.WaitGroup
+	sigChan         chan os.Signal
+	state           state
+	lock            *sync.RWMutex
+	BeforeBegin     func(network, address string)
+	OnShutdown      func()
+}
+
+// NewServer creates a server on network at provided address
+func NewServer(network, address string) *Server {
+	runningServerReg.Lock()
+	defer runningServerReg.Unlock()
+
+	if IsChild {
+		log.Info("Restarting new server: %s:%s on PID: %d", network, address, os.Getpid())
+	} else {
+		log.Info("Starting new server: %s:%s on PID: %d", network, address, os.Getpid())
+	}
+	srv := &Server{
+		wg:              sync.WaitGroup{},
+		sigChan:         make(chan os.Signal),
+		PreSignalHooks:  map[os.Signal][]func(){},
+		PostSignalHooks: map[os.Signal][]func(){},
+		state:           stateInit,
+		lock:            &sync.RWMutex{},
+		network:         network,
+		address:         address,
+	}
+
+	srv.BeforeBegin = func(network, addr string) {
+		log.Debug("Starting server on %s:%s (PID: %d)", network, addr, syscall.Getpid())
+	}
+
+	return srv
+}
+
+// ListenAndServe listens on the provided network address and then calls Serve
+// to handle requests on incoming connections.
+func (srv *Server) ListenAndServe(serve ServeFunction) error {
+	go srv.handleSignals()
+
+	l, err := GetListener(srv.network, srv.address)
+	if err != nil {
+		log.Error("Unable to GetListener: %v", err)
+		return err
+	}
+
+	srv.listener = newWrappedListener(l, srv)
+
+	if IsChild {
+		_ = syscall.Kill(syscall.Getppid(), syscall.SIGTERM)
+	}
+
+	srv.BeforeBegin(srv.network, srv.address)
+
+	return srv.Serve(serve)
+}
+
+// ListenAndServeTLS listens on the provided network address and then calls
+// Serve to handle requests on incoming TLS connections.
+//
+// Filenames containing a certificate and matching private key for the server must
+// be provided. If the certificate is signed by a certificate authority, the
+// certFile should be the concatenation of the server's certificate followed by the
+// CA's certificate.
+func (srv *Server) ListenAndServeTLS(certFile, keyFile string, serve ServeFunction) error {
+	config := &tls.Config{}
+	if config.NextProtos == nil {
+		config.NextProtos = []string{"http/1.1"}
+	}
+
+	config.Certificates = make([]tls.Certificate, 1)
+	var err error
+	config.Certificates[0], err = tls.LoadX509KeyPair(certFile, keyFile)
+	if err != nil {
+		log.Error("Failed to load https cert file %s for %s:%s: %v", certFile, srv.network, srv.address, err)
+		return err
+	}
+	return srv.ListenAndServeTLSConfig(config, serve)
+}
+
+// ListenAndServeTLSConfig listens on the provided network address and then calls
+// Serve to handle requests on incoming TLS connections.
+func (srv *Server) ListenAndServeTLSConfig(tlsConfig *tls.Config, serve ServeFunction) error {
+	go srv.handleSignals()
+
+	l, err := GetListener(srv.network, srv.address)
+	if err != nil {
+		log.Error("Unable to get Listener: %v", err)
+		return err
+	}
+
+	wl := newWrappedListener(l, srv)
+	srv.listener = tls.NewListener(wl, tlsConfig)
+
+	if IsChild {
+		_ = syscall.Kill(syscall.Getppid(), syscall.SIGTERM)
+	}
+	srv.BeforeBegin(srv.network, srv.address)
+
+	return srv.Serve(serve)
+}
+
+// Serve accepts incoming HTTP connections on the wrapped listener l, creating a new
+// service goroutine for each. The service goroutines read requests and then call
+// handler to reply to them. Handler is typically nil, in which case the
+// DefaultServeMux is used.
+//
+// In addition to the standard Serve behaviour each connection is added to a
+// sync.Waitgroup so that all outstanding connections can be served before shutting
+// down the server.
+func (srv *Server) Serve(serve ServeFunction) error {
+	defer log.Debug("Serve() returning... (PID: %d)", syscall.Getpid())
+	srv.setState(stateRunning)
+	err := serve(srv.listener)
+	log.Debug("Waiting for connections to finish... (PID: %d)", syscall.Getpid())
+	srv.wg.Wait()
+	srv.setState(stateTerminate)
+	// use of closed means that the listeners are closed - i.e. we should be shutting down - return nil
+	if err != nil && strings.Contains(err.Error(), "use of closed") {
+		return nil
+	}
+	return err
+}
+
+func (srv *Server) getState() state {
+	srv.lock.RLock()
+	defer srv.lock.RUnlock()
+
+	return srv.state
+}
+
+func (srv *Server) setState(st state) {
+	srv.lock.Lock()
+	defer srv.lock.Unlock()
+
+	srv.state = st
+}
+
+type wrappedListener struct {
+	net.Listener
+	stopped bool
+	server  *Server
+}
+
+func newWrappedListener(l net.Listener, srv *Server) *wrappedListener {
+	return &wrappedListener{
+		Listener: l,
+		server:   srv,
+	}
+}
+
+func (wl *wrappedListener) Accept() (net.Conn, error) {
+	var c net.Conn
+	// Set keepalive on TCPListeners connections.
+	if tcl, ok := wl.Listener.(*net.TCPListener); ok {
+		tc, err := tcl.AcceptTCP()
+		if err != nil {
+			return nil, err
+		}
+		_ = tc.SetKeepAlive(true)                  // see http.tcpKeepAliveListener
+		_ = tc.SetKeepAlivePeriod(3 * time.Minute) // see http.tcpKeepAliveListener
+		c = tc
+	} else {
+		var err error
+		c, err = wl.Listener.Accept()
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	c = wrappedConn{
+		Conn:   c,
+		server: wl.server,
+	}
+
+	wl.server.wg.Add(1)
+	return c, nil
+}
+
+func (wl *wrappedListener) Close() error {
+	if wl.stopped {
+		return syscall.EINVAL
+	}
+
+	wl.stopped = true
+	return wl.Listener.Close()
+}
+
+func (wl *wrappedListener) File() (*os.File, error) {
+	// returns a dup(2) - FD_CLOEXEC flag *not* set so the listening socket can be passed to child processes
+	return wl.Listener.(filer).File()
+}
+
+type wrappedConn struct {
+	net.Conn
+	server *Server
+}
+
+func (w wrappedConn) Close() error {
+	err := w.Conn.Close()
+	if err == nil {
+		w.server.wg.Done()
+	}
+	return err
+}
diff --git a/modules/graceful/server_hooks.go b/modules/graceful/server_hooks.go
new file mode 100644
index 0000000000..a80d955556
--- /dev/null
+++ b/modules/graceful/server_hooks.go
@@ -0,0 +1,119 @@
+// Copyright 2019 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package graceful
+
+import (
+	"errors"
+	"fmt"
+	"os"
+	"runtime"
+	"time"
+
+	"code.gitea.io/gitea/modules/log"
+	"code.gitea.io/gitea/modules/setting"
+)
+
+// shutdown closes the listener so that no new connections are accepted
+// and starts a goroutine that will hammer (stop all running requests) the server
+// after setting.GracefulHammerTime.
+func (srv *Server) shutdown() {
+	// only shutdown if we're running.
+	if srv.getState() != stateRunning {
+		return
+	}
+
+	srv.setState(stateShuttingDown)
+	if setting.GracefulHammerTime >= 0 {
+		go srv.hammerTime(setting.GracefulHammerTime)
+	}
+
+	if srv.OnShutdown != nil {
+		srv.OnShutdown()
+	}
+	err := srv.listener.Close()
+	if err != nil {
+		log.Error("PID: %d Listener.Close() error: %v", os.Getpid(), err)
+	} else {
+		log.Info("PID: %d Listener (%s) closed.", os.Getpid(), srv.listener.Addr())
+	}
+}
+
+// hammerTime forces the server to shutdown in a given timeout - whether it
+// finished outstanding requests or not. if Read/WriteTimeout are not set or the
+// max header size is very big a connection could hang...
+//
+// srv.Serve() will not return until all connections are served. this will
+// unblock the srv.wg.Wait() in Serve() thus causing ListenAndServe* functions to
+// return.
+func (srv *Server) hammerTime(d time.Duration) {
+	defer func() {
+		// We call srv.wg.Done() until it panics.
+		// This happens if we call Done() when the WaitGroup counter is already at 0
+		// So if it panics -> we're done, Serve() will return and the
+		// parent will goroutine will exit.
+		if r := recover(); r != nil {
+			log.Error("WaitGroup at 0: Error: %v", r)
+		}
+	}()
+	if srv.getState() != stateShuttingDown {
+		return
+	}
+	time.Sleep(d)
+	log.Warn("Forcefully shutting down parent")
+	for {
+		if srv.getState() == stateTerminate {
+			break
+		}
+		srv.wg.Done()
+
+		// Give other goroutines a chance to finish before we forcibly stop them.
+		runtime.Gosched()
+	}
+}
+
+func (srv *Server) fork() error {
+	runningServerReg.Lock()
+	defer runningServerReg.Unlock()
+
+	// only one server instance should fork!
+	if runningServersForked {
+		return errors.New("another process already forked. Ignoring this one")
+	}
+
+	runningServersForked = true
+
+	// We need to move the file logs to append pids
+	setting.RestartLogsWithPIDSuffix()
+
+	_, err := RestartProcess()
+
+	return err
+}
+
+// RegisterPreSignalHook registers a function to be run before the signal handler for
+// a given signal. These are not mutex locked and should therefore be only called before Serve.
+func (srv *Server) RegisterPreSignalHook(sig os.Signal, f func()) (err error) {
+	for _, s := range hookableSignals {
+		if s == sig {
+			srv.PreSignalHooks[sig] = append(srv.PreSignalHooks[sig], f)
+			return
+		}
+	}
+	err = fmt.Errorf("Signal %v is not supported", sig)
+	return
+}
+
+// RegisterPostSignalHook registers a function to be run after the signal handler for
+// a given signal. These are not mutex locked and should therefore be only called before Serve.
+func (srv *Server) RegisterPostSignalHook(sig os.Signal, f func()) (err error) {
+	for _, s := range hookableSignals {
+		if s == sig {
+			srv.PostSignalHooks[sig] = append(srv.PostSignalHooks[sig], f)
+			return
+		}
+	}
+	err = fmt.Errorf("Signal %v is not supported", sig)
+	return
+}
diff --git a/modules/graceful/server_http.go b/modules/graceful/server_http.go
new file mode 100644
index 0000000000..1052637d5e
--- /dev/null
+++ b/modules/graceful/server_http.go
@@ -0,0 +1,45 @@
+// Copyright 2019 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package graceful
+
+import (
+	"crypto/tls"
+	"net/http"
+)
+
+func newHTTPServer(network, address string, handler http.Handler) (*Server, ServeFunction) {
+	server := NewServer(network, address)
+	httpServer := http.Server{
+		ReadTimeout:    DefaultReadTimeOut,
+		WriteTimeout:   DefaultWriteTimeOut,
+		MaxHeaderBytes: DefaultMaxHeaderBytes,
+		Handler:        handler,
+	}
+	server.OnShutdown = func() {
+		httpServer.SetKeepAlivesEnabled(false)
+	}
+	return server, httpServer.Serve
+}
+
+// HTTPListenAndServe listens on the provided network address and then calls Serve
+// to handle requests on incoming connections.
+func HTTPListenAndServe(network, address string, handler http.Handler) error {
+	server, lHandler := newHTTPServer(network, address, handler)
+	return server.ListenAndServe(lHandler)
+}
+
+// HTTPListenAndServeTLS listens on the provided network address and then calls Serve
+// to handle requests on incoming connections.
+func HTTPListenAndServeTLS(network, address, certFile, keyFile string, handler http.Handler) error {
+	server, lHandler := newHTTPServer(network, address, handler)
+	return server.ListenAndServeTLS(certFile, keyFile, lHandler)
+}
+
+// HTTPListenAndServeTLSConfig listens on the provided network address and then calls Serve
+// to handle requests on incoming connections.
+func HTTPListenAndServeTLSConfig(network, address string, tlsConfig *tls.Config, handler http.Handler) error {
+	server, lHandler := newHTTPServer(network, address, handler)
+	return server.ListenAndServeTLSConfig(tlsConfig, lHandler)
+}
diff --git a/modules/graceful/server_signals.go b/modules/graceful/server_signals.go
new file mode 100644
index 0000000000..ea76b5509c
--- /dev/null
+++ b/modules/graceful/server_signals.go
@@ -0,0 +1,93 @@
+// Copyright 2019 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package graceful
+
+import (
+	"os"
+	"os/signal"
+	"syscall"
+	"time"
+
+	"code.gitea.io/gitea/modules/log"
+	"code.gitea.io/gitea/modules/setting"
+)
+
+var hookableSignals []os.Signal
+
+func init() {
+	hookableSignals = []os.Signal{
+		syscall.SIGHUP,
+		syscall.SIGUSR1,
+		syscall.SIGUSR2,
+		syscall.SIGINT,
+		syscall.SIGTERM,
+		syscall.SIGTSTP,
+	}
+}
+
+// handleSignals listens for os Signals and calls any hooked in function that the
+// user had registered with the signal.
+func (srv *Server) handleSignals() {
+	var sig os.Signal
+
+	signal.Notify(
+		srv.sigChan,
+		hookableSignals...,
+	)
+
+	pid := syscall.Getpid()
+	for {
+		sig = <-srv.sigChan
+		srv.preSignalHooks(sig)
+		switch sig {
+		case syscall.SIGHUP:
+			if setting.GracefulRestartable {
+				log.Info("PID: %d. Received SIGHUP. Forking...", pid)
+				err := srv.fork()
+				if err != nil {
+					log.Error("Error whilst forking from PID: %d : %v", pid, err)
+				}
+			} else {
+				log.Info("PID: %d. Received SIGHUP. Not set restartable. Shutting down...", pid)
+
+				srv.shutdown()
+			}
+		case syscall.SIGUSR1:
+			log.Info("PID %d. Received SIGUSR1.", pid)
+		case syscall.SIGUSR2:
+			log.Warn("PID %d. Received SIGUSR2. Hammering...", pid)
+			srv.hammerTime(0 * time.Second)
+		case syscall.SIGINT:
+			log.Warn("PID %d. Received SIGINT. Shutting down...", pid)
+			srv.shutdown()
+		case syscall.SIGTERM:
+			log.Warn("PID %d. Received SIGTERM. Shutting down...", pid)
+			srv.shutdown()
+		case syscall.SIGTSTP:
+			log.Info("PID %d. Received SIGTSTP.")
+		default:
+			log.Info("PID %d. Received %v.", sig)
+		}
+		srv.postSignalHooks(sig)
+	}
+}
+
+func (srv *Server) preSignalHooks(sig os.Signal) {
+	if _, notSet := srv.PreSignalHooks[sig]; !notSet {
+		return
+	}
+	for _, f := range srv.PreSignalHooks[sig] {
+		f()
+	}
+}
+
+func (srv *Server) postSignalHooks(sig os.Signal) {
+	if _, notSet := srv.PostSignalHooks[sig]; !notSet {
+		return
+	}
+	for _, f := range srv.PostSignalHooks[sig] {
+		f()
+	}
+}
diff --git a/modules/indexer/issues/indexer.go b/modules/indexer/issues/indexer.go
index df8bfd6305..4f410daf4c 100644
--- a/modules/indexer/issues/indexer.go
+++ b/modules/indexer/issues/indexer.go
@@ -5,9 +5,11 @@
 package issues
 
 import (
-	"fmt"
+	"sync"
+	"time"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/modules/graceful"
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/setting"
 	"code.gitea.io/gitea/modules/util"
@@ -45,78 +47,143 @@ type Indexer interface {
 	Search(kw string, repoID int64, limit, start int) (*SearchResult, error)
 }
 
+type indexerHolder struct {
+	indexer Indexer
+	mutex   sync.RWMutex
+	cond    *sync.Cond
+}
+
+func newIndexerHolder() *indexerHolder {
+	h := &indexerHolder{}
+	h.cond = sync.NewCond(h.mutex.RLocker())
+	return h
+}
+
+func (h *indexerHolder) set(indexer Indexer) {
+	h.mutex.Lock()
+	defer h.mutex.Unlock()
+	h.indexer = indexer
+	h.cond.Broadcast()
+}
+
+func (h *indexerHolder) get() Indexer {
+	h.mutex.RLock()
+	defer h.mutex.RUnlock()
+	if h.indexer == nil {
+		h.cond.Wait()
+	}
+	return h.indexer
+}
+
 var (
+	issueIndexerChannel = make(chan *IndexerData, setting.Indexer.UpdateQueueLength)
 	// issueIndexerQueue queue of issue ids to be updated
 	issueIndexerQueue Queue
-	issueIndexer      Indexer
+	holder            = newIndexerHolder()
 )
 
 // InitIssueIndexer initialize issue indexer, syncReindex is true then reindex until
 // all issue index done.
-func InitIssueIndexer(syncReindex bool) error {
-	var populate bool
-	var dummyQueue bool
-	switch setting.Indexer.IssueType {
-	case "bleve":
-		issueIndexer = NewBleveIndexer(setting.Indexer.IssuePath)
-		exist, err := issueIndexer.Init()
-		if err != nil {
-			return err
+func InitIssueIndexer(syncReindex bool) {
+	waitChannel := make(chan time.Duration)
+	go func() {
+		start := time.Now()
+		log.Info("Initializing Issue Indexer")
+		var populate bool
+		var dummyQueue bool
+		switch setting.Indexer.IssueType {
+		case "bleve":
+			issueIndexer := NewBleveIndexer(setting.Indexer.IssuePath)
+			exist, err := issueIndexer.Init()
+			if err != nil {
+				log.Fatal("Unable to initialize Bleve Issue Indexer: %v", err)
+			}
+			populate = !exist
+			holder.set(issueIndexer)
+		case "db":
+			issueIndexer := &DBIndexer{}
+			holder.set(issueIndexer)
+			dummyQueue = true
+		default:
+			log.Fatal("Unknown issue indexer type: %s", setting.Indexer.IssueType)
 		}
-		populate = !exist
-	case "db":
-		issueIndexer = &DBIndexer{}
-		dummyQueue = true
-	default:
-		return fmt.Errorf("unknow issue indexer type: %s", setting.Indexer.IssueType)
-	}
 
-	if dummyQueue {
-		issueIndexerQueue = &DummyQueue{}
-		return nil
-	}
+		if dummyQueue {
+			issueIndexerQueue = &DummyQueue{}
+		} else {
+			var err error
+			switch setting.Indexer.IssueQueueType {
+			case setting.LevelQueueType:
+				issueIndexerQueue, err = NewLevelQueue(
+					holder.get(),
+					setting.Indexer.IssueQueueDir,
+					setting.Indexer.IssueQueueBatchNumber)
+				if err != nil {
+					log.Fatal(
+						"Unable create level queue for issue queue dir: %s batch number: %d : %v",
+						setting.Indexer.IssueQueueDir,
+						setting.Indexer.IssueQueueBatchNumber,
+						err)
+				}
+			case setting.ChannelQueueType:
+				issueIndexerQueue = NewChannelQueue(holder.get(), setting.Indexer.IssueQueueBatchNumber)
+			case setting.RedisQueueType:
+				addrs, pass, idx, err := parseConnStr(setting.Indexer.IssueQueueConnStr)
+				if err != nil {
+					log.Fatal("Unable to parse connection string for RedisQueueType: %s : %v",
+						setting.Indexer.IssueQueueConnStr,
+						err)
+				}
+				issueIndexerQueue, err = NewRedisQueue(addrs, pass, idx, holder.get(), setting.Indexer.IssueQueueBatchNumber)
+				if err != nil {
+					log.Fatal("Unable to create RedisQueue: %s : %v",
+						setting.Indexer.IssueQueueConnStr,
+						err)
+				}
+			default:
+				log.Fatal("Unsupported indexer queue type: %v",
+					setting.Indexer.IssueQueueType)
+			}
 
-	var err error
-	switch setting.Indexer.IssueQueueType {
-	case setting.LevelQueueType:
-		issueIndexerQueue, err = NewLevelQueue(
-			issueIndexer,
-			setting.Indexer.IssueQueueDir,
-			setting.Indexer.IssueQueueBatchNumber)
-		if err != nil {
-			return err
+			go func() {
+				err = issueIndexerQueue.Run()
+				if err != nil {
+					log.Error("issueIndexerQueue.Run: %v", err)
+				}
+			}()
 		}
-	case setting.ChannelQueueType:
-		issueIndexerQueue = NewChannelQueue(issueIndexer, setting.Indexer.IssueQueueBatchNumber)
-	case setting.RedisQueueType:
-		addrs, pass, idx, err := parseConnStr(setting.Indexer.IssueQueueConnStr)
-		if err != nil {
-			return err
-		}
-		issueIndexerQueue, err = NewRedisQueue(addrs, pass, idx, issueIndexer, setting.Indexer.IssueQueueBatchNumber)
-		if err != nil {
-			return err
-		}
-	default:
-		return fmt.Errorf("Unsupported indexer queue type: %v", setting.Indexer.IssueQueueType)
-	}
 
-	go func() {
-		err = issueIndexerQueue.Run()
-		if err != nil {
-			log.Error("issueIndexerQueue.Run: %v", err)
-		}
-	}()
+		go func() {
+			for data := range issueIndexerChannel {
+				_ = issueIndexerQueue.Push(data)
+			}
+		}()
 
-	if populate {
-		if syncReindex {
-			populateIssueIndexer()
-		} else {
-			go populateIssueIndexer()
+		if populate {
+			if syncReindex {
+				populateIssueIndexer()
+			} else {
+				go populateIssueIndexer()
+			}
 		}
+		waitChannel <- time.Since(start)
+	}()
+	if syncReindex {
+		<-waitChannel
+	} else if setting.Indexer.StartupTimeout > 0 {
+		go func() {
+			timeout := setting.Indexer.StartupTimeout
+			if graceful.IsChild && setting.GracefulHammerTime > 0 {
+				timeout += setting.GracefulHammerTime
+			}
+			select {
+			case duration := <-waitChannel:
+				log.Info("Issue Indexer Initialization took %v", duration)
+			case <-time.After(timeout):
+				log.Fatal("Issue Indexer Initialization timed-out after: %v", timeout)
+			}
+		}()
 	}
-
-	return nil
 }
 
 // populateIssueIndexer populate the issue indexer with issue data
@@ -166,13 +233,13 @@ func UpdateIssueIndexer(issue *models.Issue) {
 			comments = append(comments, comment.Content)
 		}
 	}
-	_ = issueIndexerQueue.Push(&IndexerData{
+	issueIndexerChannel <- &IndexerData{
 		ID:       issue.ID,
 		RepoID:   issue.RepoID,
 		Title:    issue.Title,
 		Content:  issue.Content,
 		Comments: comments,
-	})
+	}
 }
 
 // DeleteRepoIssueIndexer deletes repo's all issues indexes
@@ -188,16 +255,16 @@ func DeleteRepoIssueIndexer(repo *models.Repository) {
 		return
 	}
 
-	_ = issueIndexerQueue.Push(&IndexerData{
+	issueIndexerChannel <- &IndexerData{
 		IDs:      ids,
 		IsDelete: true,
-	})
+	}
 }
 
 // SearchIssuesByKeyword search issue ids by keywords and repo id
 func SearchIssuesByKeyword(repoID int64, keyword string) ([]int64, error) {
 	var issueIDs []int64
-	res, err := issueIndexer.Search(keyword, repoID, 1000, 0)
+	res, err := holder.get().Search(keyword, repoID, 1000, 0)
 	if err != nil {
 		return nil, err
 	}
diff --git a/modules/indexer/issues/indexer_test.go b/modules/indexer/issues/indexer_test.go
index 59a7beed47..212c2edfbe 100644
--- a/modules/indexer/issues/indexer_test.go
+++ b/modules/indexer/issues/indexer_test.go
@@ -5,7 +5,6 @@
 package issues
 
 import (
-	"fmt"
 	"os"
 	"path/filepath"
 	"testing"
@@ -17,11 +16,6 @@ import (
 	"github.com/stretchr/testify/assert"
 )
 
-func fatalTestError(fmtStr string, args ...interface{}) {
-	fmt.Fprintf(os.Stderr, fmtStr, args...)
-	os.Exit(1)
-}
-
 func TestMain(m *testing.M) {
 	models.MainTest(m, filepath.Join("..", "..", ".."))
 }
@@ -32,9 +26,7 @@ func TestBleveSearchIssues(t *testing.T) {
 	os.RemoveAll(setting.Indexer.IssueQueueDir)
 	os.RemoveAll(setting.Indexer.IssuePath)
 	setting.Indexer.IssueType = "bleve"
-	if err := InitIssueIndexer(true); err != nil {
-		fatalTestError("Error InitIssueIndexer: %v\n", err)
-	}
+	InitIssueIndexer(true)
 
 	time.Sleep(5 * time.Second)
 
@@ -59,9 +51,7 @@ func TestDBSearchIssues(t *testing.T) {
 	assert.NoError(t, models.PrepareTestDatabase())
 
 	setting.Indexer.IssueType = "db"
-	if err := InitIssueIndexer(true); err != nil {
-		fatalTestError("Error InitIssueIndexer: %v\n", err)
-	}
+	InitIssueIndexer(true)
 
 	ids, err := SearchIssuesByKeyword(1, "issue2")
 	assert.NoError(t, err)
diff --git a/modules/indexer/repo.go b/modules/indexer/repo.go
index 91ed173aa7..841f29acd7 100644
--- a/modules/indexer/repo.go
+++ b/modules/indexer/repo.go
@@ -6,6 +6,7 @@ package indexer
 
 import (
 	"strings"
+	"sync"
 
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/setting"
@@ -25,8 +26,36 @@ const (
 	repoIndexerLatestVersion = 4
 )
 
+type bleveIndexerHolder struct {
+	index bleve.Index
+	mutex sync.RWMutex
+	cond  *sync.Cond
+}
+
+func newBleveIndexerHolder() *bleveIndexerHolder {
+	b := &bleveIndexerHolder{}
+	b.cond = sync.NewCond(b.mutex.RLocker())
+	return b
+}
+
+func (r *bleveIndexerHolder) set(index bleve.Index) {
+	r.mutex.Lock()
+	defer r.mutex.Unlock()
+	r.index = index
+	r.cond.Broadcast()
+}
+
+func (r *bleveIndexerHolder) get() bleve.Index {
+	r.mutex.RLock()
+	defer r.mutex.RUnlock()
+	if r.index == nil {
+		r.cond.Wait()
+	}
+	return r.index
+}
+
 // repoIndexer (thread-safe) index for repository contents
-var repoIndexer bleve.Index
+var indexerHolder = newBleveIndexerHolder()
 
 // RepoIndexerOp type of operation to perform on repo indexer
 type RepoIndexerOp int
@@ -73,12 +102,12 @@ func (update RepoIndexerUpdate) AddToFlushingBatch(batch rupture.FlushingBatch)
 
 // InitRepoIndexer initialize repo indexer
 func InitRepoIndexer(populateIndexer func() error) {
-	var err error
-	repoIndexer, err = openIndexer(setting.Indexer.RepoPath, repoIndexerLatestVersion)
+	indexer, err := openIndexer(setting.Indexer.RepoPath, repoIndexerLatestVersion)
 	if err != nil {
 		log.Fatal("InitRepoIndexer: %v", err)
 	}
-	if repoIndexer != nil {
+	if indexer != nil {
+		indexerHolder.set(indexer)
 		return
 	}
 
@@ -92,7 +121,6 @@ func InitRepoIndexer(populateIndexer func() error) {
 
 // createRepoIndexer create a repo indexer if one does not already exist
 func createRepoIndexer(path string, latestVersion int) error {
-	var err error
 	docMapping := bleve.NewDocumentMapping()
 	numericFieldMapping := bleve.NewNumericFieldMapping()
 	numericFieldMapping.IncludeInAll = false
@@ -103,9 +131,9 @@ func createRepoIndexer(path string, latestVersion int) error {
 	docMapping.AddFieldMappingsAt("Content", textFieldMapping)
 
 	mapping := bleve.NewIndexMapping()
-	if err = addUnicodeNormalizeTokenFilter(mapping); err != nil {
+	if err := addUnicodeNormalizeTokenFilter(mapping); err != nil {
 		return err
-	} else if err = mapping.AddCustomAnalyzer(repoIndexerAnalyzer, map[string]interface{}{
+	} else if err := mapping.AddCustomAnalyzer(repoIndexerAnalyzer, map[string]interface{}{
 		"type":          custom.Name,
 		"char_filters":  []string{},
 		"tokenizer":     unicode.Name,
@@ -117,10 +145,12 @@ func createRepoIndexer(path string, latestVersion int) error {
 	mapping.AddDocumentMapping(repoIndexerDocType, docMapping)
 	mapping.AddDocumentMapping("_all", bleve.NewDocumentDisabledMapping())
 
-	repoIndexer, err = bleve.New(path, mapping)
+	indexer, err := bleve.New(path, mapping)
 	if err != nil {
 		return err
 	}
+	indexerHolder.set(indexer)
+
 	return rupture.WriteIndexMetadata(path, &rupture.IndexMetadata{
 		Version: latestVersion,
 	})
@@ -140,14 +170,14 @@ func filenameOfIndexerID(indexerID string) string {
 
 // RepoIndexerBatch batch to add updates to
 func RepoIndexerBatch() rupture.FlushingBatch {
-	return rupture.NewFlushingBatch(repoIndexer, maxBatchSize)
+	return rupture.NewFlushingBatch(indexerHolder.get(), maxBatchSize)
 }
 
 // DeleteRepoFromIndexer delete all of a repo's files from indexer
 func DeleteRepoFromIndexer(repoID int64) error {
 	query := numericEqualityQuery(repoID, "RepoID")
 	searchRequest := bleve.NewSearchRequestOptions(query, 2147483647, 0, false)
-	result, err := repoIndexer.Search(searchRequest)
+	result, err := indexerHolder.get().Search(searchRequest)
 	if err != nil {
 		return err
 	}
@@ -196,7 +226,7 @@ func SearchRepoByKeyword(repoIDs []int64, keyword string, page, pageSize int) (i
 	searchRequest.Fields = []string{"Content", "RepoID"}
 	searchRequest.IncludeLocations = true
 
-	result, err := repoIndexer.Search(searchRequest)
+	result, err := indexerHolder.get().Search(searchRequest)
 	if err != nil {
 		return 0, nil, err
 	}
diff --git a/modules/setting/indexer.go b/modules/setting/indexer.go
index 30c670d407..fbaef3fcf2 100644
--- a/modules/setting/indexer.go
+++ b/modules/setting/indexer.go
@@ -8,6 +8,7 @@ import (
 	"path"
 	"path/filepath"
 	"strings"
+	"time"
 
 	"code.gitea.io/gitea/modules/log"
 
@@ -34,6 +35,7 @@ var (
 		IssueQueueDir         string
 		IssueQueueConnStr     string
 		IssueQueueBatchNumber int
+		StartupTimeout        time.Duration
 		IncludePatterns       []glob.Glob
 		ExcludePatterns       []glob.Glob
 	}{
@@ -67,6 +69,7 @@ func newIndexerService() {
 	Indexer.IssueQueueDir = sec.Key("ISSUE_INDEXER_QUEUE_DIR").MustString(path.Join(AppDataPath, "indexers/issues.queue"))
 	Indexer.IssueQueueConnStr = sec.Key("ISSUE_INDEXER_QUEUE_CONN_STR").MustString(path.Join(AppDataPath, ""))
 	Indexer.IssueQueueBatchNumber = sec.Key("ISSUE_INDEXER_QUEUE_BATCH_NUMBER").MustInt(20)
+	Indexer.StartupTimeout = sec.Key("STARTUP_TIMEOUT").MustDuration(30 * time.Second)
 }
 
 // IndexerGlobFromString parses a comma separated list of patterns and returns a glob.Glob slice suited for repo indexing
diff --git a/modules/setting/log.go b/modules/setting/log.go
index 5e2d2d769d..cb8f142084 100644
--- a/modules/setting/log.go
+++ b/modules/setting/log.go
@@ -6,6 +6,7 @@ package setting
 
 import (
 	"encoding/json"
+	"fmt"
 	golog "log"
 	"os"
 	"path"
@@ -17,6 +18,8 @@ import (
 	ini "gopkg.in/ini.v1"
 )
 
+var filenameSuffix = ""
+
 type defaultLogOptions struct {
 	levelName      string // LogLevel
 	flags          string
@@ -112,7 +115,7 @@ func generateLogConfig(sec *ini.Section, name string, defaults defaultLogOptions
 			panic(err.Error())
 		}
 
-		logConfig["filename"] = logPath
+		logConfig["filename"] = logPath + filenameSuffix
 		logConfig["rotate"] = sec.Key("LOG_ROTATE").MustBool(true)
 		logConfig["maxsize"] = 1 << uint(sec.Key("MAX_SIZE_SHIFT").MustInt(28))
 		logConfig["daily"] = sec.Key("DAILY_ROTATE").MustBool(true)
@@ -277,6 +280,12 @@ func newLogService() {
 	golog.SetOutput(log.NewLoggerAsWriter("INFO", log.GetLogger(log.DEFAULT)))
 }
 
+// RestartLogsWithPIDSuffix restarts the logs with a PID suffix on files
+func RestartLogsWithPIDSuffix() {
+	filenameSuffix = fmt.Sprintf(".%d", os.Getpid())
+	NewLogServices(false)
+}
+
 // NewLogServices creates all the log services
 func NewLogServices(disableConsole bool) {
 	newLogService()
diff --git a/modules/setting/setting.go b/modules/setting/setting.go
index 629a89766f..144882976f 100644
--- a/modules/setting/setting.go
+++ b/modules/setting/setting.go
@@ -97,6 +97,8 @@ var (
 	LetsEncryptTOS       bool
 	LetsEncryptDirectory string
 	LetsEncryptEmail     string
+	GracefulRestartable  bool
+	GracefulHammerTime   time.Duration
 
 	SSH = struct {
 		Disabled                 bool           `ini:"DISABLE_SSH"`
@@ -563,6 +565,8 @@ func NewContext() {
 	Domain = sec.Key("DOMAIN").MustString("localhost")
 	HTTPAddr = sec.Key("HTTP_ADDR").MustString("0.0.0.0")
 	HTTPPort = sec.Key("HTTP_PORT").MustString("3000")
+	GracefulRestartable = sec.Key("ALLOW_GRACEFUL_RESTARTS").MustBool(true)
+	GracefulHammerTime = sec.Key("GRACEFUL_HAMMER_TIME").MustDuration(60 * time.Second)
 
 	defaultAppURL := string(Protocol) + "://" + Domain
 	if (Protocol == HTTP && HTTPPort != "80") || (Protocol == HTTPS && HTTPPort != "443") {
diff --git a/modules/ssh/ssh.go b/modules/ssh/ssh.go
index 7ff0c32326..e7a694683a 100644
--- a/modules/ssh/ssh.go
+++ b/modules/ssh/ssh.go
@@ -183,12 +183,7 @@ func Listen(host string, port int, ciphers []string, keyExchanges []string, macs
 		log.Error("Failed to set Host Key. %s", err)
 	}
 
-	go func() {
-		err := srv.ListenAndServe()
-		if err != nil {
-			log.Error("Failed to serve with builtin SSH server. %s", err)
-		}
-	}()
+	go listen(&srv)
 
 }
 
diff --git a/modules/ssh/ssh_graceful.go b/modules/ssh/ssh_graceful.go
new file mode 100644
index 0000000000..d66c7d6540
--- /dev/null
+++ b/modules/ssh/ssh_graceful.go
@@ -0,0 +1,30 @@
+// +build !windows
+
+// Copyright 2019 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package ssh
+
+import (
+	"code.gitea.io/gitea/modules/graceful"
+	"code.gitea.io/gitea/modules/log"
+
+	"github.com/gliderlabs/ssh"
+)
+
+func listen(server *ssh.Server) {
+	gracefulServer := graceful.NewServer("tcp", server.Addr)
+
+	err := gracefulServer.ListenAndServe(server.Serve)
+	if err != nil {
+		log.Critical("Failed to start SSH server: %v", err)
+	}
+	log.Info("SSH Listener: %s Closed", server.Addr)
+
+}
+
+// Unused informs our cleanup routine that we will not be using a ssh port
+func Unused() {
+	graceful.InformCleanup()
+}
diff --git a/modules/ssh/ssh_windows.go b/modules/ssh/ssh_windows.go
new file mode 100644
index 0000000000..55032e17cd
--- /dev/null
+++ b/modules/ssh/ssh_windows.go
@@ -0,0 +1,24 @@
+// +build windows
+
+// Copyright 2019 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package ssh
+
+import (
+	"code.gitea.io/gitea/modules/log"
+	"github.com/gliderlabs/ssh"
+)
+
+func listen(server *ssh.Server) {
+	err := server.ListenAndServe()
+	if err != nil {
+		log.Critical("Failed to serve with builtin SSH server. %s", err)
+	}
+}
+
+// Unused does nothing on windows
+func Unused() {
+	// Do nothing
+}
diff --git a/routers/init.go b/routers/init.go
index c37bbeb6b0..e4e880dbbb 100644
--- a/routers/init.go
+++ b/routers/init.go
@@ -96,9 +96,7 @@ func GlobalInit() {
 
 		// Booting long running goroutines.
 		cron.NewContext()
-		if err := issue_indexer.InitIssueIndexer(false); err != nil {
-			log.Fatal("Failed to initialize issue indexer: %v", err)
-		}
+		issue_indexer.InitIssueIndexer(false)
 		models.InitRepoIndexer()
 		mirror_service.InitSyncMirrors()
 		models.InitDeliverHooks()
@@ -112,8 +110,15 @@ func GlobalInit() {
 	}
 	checkRunMode()
 
-	if setting.InstallLock && setting.SSH.StartBuiltinServer {
-		ssh.Listen(setting.SSH.ListenHost, setting.SSH.ListenPort, setting.SSH.ServerCiphers, setting.SSH.ServerKeyExchanges, setting.SSH.ServerMACs)
-		log.Info("SSH server started on %s:%d. Cipher list (%v), key exchange algorithms (%v), MACs (%v)", setting.SSH.ListenHost, setting.SSH.ListenPort, setting.SSH.ServerCiphers, setting.SSH.ServerKeyExchanges, setting.SSH.ServerMACs)
+	// Now because Install will re-run GlobalInit once it has set InstallLock
+	// we can't tell if the ssh port will remain unused until that's done.
+	// However, see FIXME comment in install.go
+	if setting.InstallLock {
+		if setting.SSH.StartBuiltinServer {
+			ssh.Listen(setting.SSH.ListenHost, setting.SSH.ListenPort, setting.SSH.ServerCiphers, setting.SSH.ServerKeyExchanges, setting.SSH.ServerMACs)
+			log.Info("SSH server started on %s:%d. Cipher list (%v), key exchange algorithms (%v), MACs (%v)", setting.SSH.ListenHost, setting.SSH.ListenPort, setting.SSH.ServerCiphers, setting.SSH.ServerKeyExchanges, setting.SSH.ServerMACs)
+		} else {
+			ssh.Unused()
+		}
 	}
 }
diff --git a/routers/install.go b/routers/install.go
index 16888adc82..8f3d0d5ae6 100644
--- a/routers/install.go
+++ b/routers/install.go
@@ -386,6 +386,12 @@ func InstallPost(ctx *context.Context, form auth.InstallForm) {
 	}
 
 	log.Info("First-time run install finished!")
+	// FIXME: This isn't really enough to completely take account of new configuration
+	// We should really be restarting:
+	// - On windows this is probably just a simple restart
+	// - On linux we can't just use graceful.RestartProcess() everything that was passed in on LISTEN_FDS
+	//   (active or not) needs to be passed out and everything new passed out too.
+	//   This means we need to prevent the cleanup goroutine from running prior to the second GlobalInit
 	ctx.Flash.Success(ctx.Tr("install.install_success"))
 	ctx.Redirect(form.AppURL + "user/login")
 }
diff --git a/vendor/github.com/facebookgo/clock/LICENSE b/vendor/github.com/facebookgo/clock/LICENSE
deleted file mode 100644
index ce212cb1ce..0000000000
--- a/vendor/github.com/facebookgo/clock/LICENSE
+++ /dev/null
@@ -1,21 +0,0 @@
-The MIT License (MIT)
-
-Copyright (c) 2014 Ben Johnson
-
-Permission is hereby granted, free of charge, to any person obtaining a copy
-of this software and associated documentation files (the "Software"), to deal
-in the Software without restriction, including without limitation the rights
-to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-copies of the Software, and to permit persons to whom the Software is
-furnished to do so, subject to the following conditions:
-
-The above copyright notice and this permission notice shall be included in all
-copies or substantial portions of the Software.
-
-THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
-SOFTWARE.
diff --git a/vendor/github.com/facebookgo/clock/README.md b/vendor/github.com/facebookgo/clock/README.md
deleted file mode 100644
index 5d4f4fe72e..0000000000
--- a/vendor/github.com/facebookgo/clock/README.md
+++ /dev/null
@@ -1,104 +0,0 @@
-clock [![Build Status](https://drone.io/github.com/benbjohnson/clock/status.png)](https://drone.io/github.com/benbjohnson/clock/latest) [![Coverage Status](https://coveralls.io/repos/benbjohnson/clock/badge.png?branch=master)](https://coveralls.io/r/benbjohnson/clock?branch=master) [![GoDoc](https://godoc.org/github.com/benbjohnson/clock?status.png)](https://godoc.org/github.com/benbjohnson/clock) ![Project status](http://img.shields.io/status/experimental.png?color=red)
-=====
-
-Clock is a small library for mocking time in Go. It provides an interface
-around the standard library's [`time`][time] package so that the application
-can use the realtime clock while tests can use the mock clock.
-
-[time]: http://golang.org/pkg/time/
-
-
-## Usage
-
-### Realtime Clock
-
-Your application can maintain a `Clock` variable that will allow realtime and
-mock clocks to be interchangable. For example, if you had an `Application` type:
-
-```go
-import "github.com/benbjohnson/clock"
-
-type Application struct {
-	Clock clock.Clock
-}
-```
-
-You could initialize it to use the realtime clock like this:
-
-```go
-var app Application
-app.Clock = clock.New()
-...
-```
-
-Then all timers and time-related functionality should be performed from the
-`Clock` variable.
-
-
-### Mocking time
-
-In your tests, you will want to use a `Mock` clock:
-
-```go
-import (
-	"testing"
-
-	"github.com/benbjohnson/clock"
-)
-
-func TestApplication_DoSomething(t *testing.T) {
-	mock := clock.NewMock()
-	app := Application{Clock: mock}
-	...
-}
-```
-
-Now that you've initialized your application to use the mock clock, you can
-adjust the time programmatically. The mock clock always starts from the Unix
-epoch (midnight, Jan 1, 1970 UTC).
-
-
-### Controlling time
-
-The mock clock provides the same functions that the standard library's `time`
-package provides. For example, to find the current time, you use the `Now()`
-function:
-
-```go
-mock := clock.NewMock()
-
-// Find the current time.
-mock.Now().UTC() // 1970-01-01 00:00:00 +0000 UTC
-
-// Move the clock forward.
-mock.Add(2 * time.Hour)
-
-// Check the time again. It's 2 hours later!
-mock.Now().UTC() // 1970-01-01 02:00:00 +0000 UTC
-```
-
-Timers and Tickers are also controlled by this same mock clock. They will only
-execute when the clock is moved forward:
-
-```
-mock := clock.NewMock()
-count := 0
-
-// Kick off a timer to increment every 1 mock second.
-go func() {
-    ticker := clock.Ticker(1 * time.Second)
-    for {
-        <-ticker.C
-        count++
-    }
-}()
-runtime.Gosched()
-
-// Move the clock forward 10 second.
-mock.Add(10 * time.Second)
-
-// This prints 10.
-fmt.Println(count)
-```
-
-
diff --git a/vendor/github.com/facebookgo/clock/clock.go b/vendor/github.com/facebookgo/clock/clock.go
deleted file mode 100644
index bca1a7ba8b..0000000000
--- a/vendor/github.com/facebookgo/clock/clock.go
+++ /dev/null
@@ -1,363 +0,0 @@
-package clock
-
-import (
-	"runtime"
-	"sort"
-	"sync"
-	"time"
-)
-
-// Clock represents an interface to the functions in the standard library time
-// package. Two implementations are available in the clock package. The first
-// is a real-time clock which simply wraps the time package's functions. The
-// second is a mock clock which will only make forward progress when
-// programmatically adjusted.
-type Clock interface {
-	After(d time.Duration) <-chan time.Time
-	AfterFunc(d time.Duration, f func()) *Timer
-	Now() time.Time
-	Sleep(d time.Duration)
-	Tick(d time.Duration) <-chan time.Time
-	Ticker(d time.Duration) *Ticker
-	Timer(d time.Duration) *Timer
-}
-
-// New returns an instance of a real-time clock.
-func New() Clock {
-	return &clock{}
-}
-
-// clock implements a real-time clock by simply wrapping the time package functions.
-type clock struct{}
-
-func (c *clock) After(d time.Duration) <-chan time.Time { return time.After(d) }
-
-func (c *clock) AfterFunc(d time.Duration, f func()) *Timer {
-	return &Timer{timer: time.AfterFunc(d, f)}
-}
-
-func (c *clock) Now() time.Time { return time.Now() }
-
-func (c *clock) Sleep(d time.Duration) { time.Sleep(d) }
-
-func (c *clock) Tick(d time.Duration) <-chan time.Time { return time.Tick(d) }
-
-func (c *clock) Ticker(d time.Duration) *Ticker {
-	t := time.NewTicker(d)
-	return &Ticker{C: t.C, ticker: t}
-}
-
-func (c *clock) Timer(d time.Duration) *Timer {
-	t := time.NewTimer(d)
-	return &Timer{C: t.C, timer: t}
-}
-
-// Mock represents a mock clock that only moves forward programmically.
-// It can be preferable to a real-time clock when testing time-based functionality.
-type Mock struct {
-	mu     sync.Mutex
-	now    time.Time   // current time
-	timers clockTimers // tickers & timers
-
-	calls      Calls
-	waiting    []waiting
-	callsMutex sync.Mutex
-}
-
-// NewMock returns an instance of a mock clock.
-// The current time of the mock clock on initialization is the Unix epoch.
-func NewMock() *Mock {
-	return &Mock{now: time.Unix(0, 0)}
-}
-
-// Add moves the current time of the mock clock forward by the duration.
-// This should only be called from a single goroutine at a time.
-func (m *Mock) Add(d time.Duration) {
-	// Calculate the final current time.
-	t := m.now.Add(d)
-
-	// Continue to execute timers until there are no more before the new time.
-	for {
-		if !m.runNextTimer(t) {
-			break
-		}
-	}
-
-	// Ensure that we end with the new time.
-	m.mu.Lock()
-	m.now = t
-	m.mu.Unlock()
-
-	// Give a small buffer to make sure the other goroutines get handled.
-	gosched()
-}
-
-// runNextTimer executes the next timer in chronological order and moves the
-// current time to the timer's next tick time. The next time is not executed if
-// it's next time if after the max time. Returns true if a timer is executed.
-func (m *Mock) runNextTimer(max time.Time) bool {
-	m.mu.Lock()
-
-	// Sort timers by time.
-	sort.Sort(m.timers)
-
-	// If we have no more timers then exit.
-	if len(m.timers) == 0 {
-		m.mu.Unlock()
-		return false
-	}
-
-	// Retrieve next timer. Exit if next tick is after new time.
-	t := m.timers[0]
-	if t.Next().After(max) {
-		m.mu.Unlock()
-		return false
-	}
-
-	// Move "now" forward and unlock clock.
-	m.now = t.Next()
-	m.mu.Unlock()
-
-	// Execute timer.
-	t.Tick(m.now)
-	return true
-}
-
-// After waits for the duration to elapse and then sends the current time on the returned channel.
-func (m *Mock) After(d time.Duration) <-chan time.Time {
-	defer m.inc(&m.calls.After)
-	return m.Timer(d).C
-}
-
-// AfterFunc waits for the duration to elapse and then executes a function.
-// A Timer is returned that can be stopped.
-func (m *Mock) AfterFunc(d time.Duration, f func()) *Timer {
-	defer m.inc(&m.calls.AfterFunc)
-	t := m.Timer(d)
-	t.C = nil
-	t.fn = f
-	return t
-}
-
-// Now returns the current wall time on the mock clock.
-func (m *Mock) Now() time.Time {
-	defer m.inc(&m.calls.Now)
-	m.mu.Lock()
-	defer m.mu.Unlock()
-	return m.now
-}
-
-// Sleep pauses the goroutine for the given duration on the mock clock.
-// The clock must be moved forward in a separate goroutine.
-func (m *Mock) Sleep(d time.Duration) {
-	defer m.inc(&m.calls.Sleep)
-	<-m.After(d)
-}
-
-// Tick is a convenience function for Ticker().
-// It will return a ticker channel that cannot be stopped.
-func (m *Mock) Tick(d time.Duration) <-chan time.Time {
-	defer m.inc(&m.calls.Tick)
-	return m.Ticker(d).C
-}
-
-// Ticker creates a new instance of Ticker.
-func (m *Mock) Ticker(d time.Duration) *Ticker {
-	defer m.inc(&m.calls.Ticker)
-	m.mu.Lock()
-	defer m.mu.Unlock()
-	ch := make(chan time.Time)
-	t := &Ticker{
-		C:    ch,
-		c:    ch,
-		mock: m,
-		d:    d,
-		next: m.now.Add(d),
-	}
-	m.timers = append(m.timers, (*internalTicker)(t))
-	return t
-}
-
-// Timer creates a new instance of Timer.
-func (m *Mock) Timer(d time.Duration) *Timer {
-	defer m.inc(&m.calls.Timer)
-	m.mu.Lock()
-	defer m.mu.Unlock()
-	ch := make(chan time.Time)
-	t := &Timer{
-		C:    ch,
-		c:    ch,
-		mock: m,
-		next: m.now.Add(d),
-	}
-	m.timers = append(m.timers, (*internalTimer)(t))
-	return t
-}
-
-func (m *Mock) removeClockTimer(t clockTimer) {
-	m.mu.Lock()
-	defer m.mu.Unlock()
-	for i, timer := range m.timers {
-		if timer == t {
-			copy(m.timers[i:], m.timers[i+1:])
-			m.timers[len(m.timers)-1] = nil
-			m.timers = m.timers[:len(m.timers)-1]
-			break
-		}
-	}
-	sort.Sort(m.timers)
-}
-
-func (m *Mock) inc(addr *uint32) {
-	m.callsMutex.Lock()
-	defer m.callsMutex.Unlock()
-	*addr++
-	var newWaiting []waiting
-	for _, w := range m.waiting {
-		if m.calls.atLeast(w.expected) {
-			close(w.done)
-			continue
-		}
-		newWaiting = append(newWaiting, w)
-	}
-	m.waiting = newWaiting
-}
-
-// Wait waits for at least the relevant calls before returning. The expected
-// Calls are always over the lifetime of the Mock. Values in the Calls struct
-// are used as the minimum number of calls, this allows you to wait for only
-// the calls you care about.
-func (m *Mock) Wait(s Calls) {
-	m.callsMutex.Lock()
-	if m.calls.atLeast(s) {
-		m.callsMutex.Unlock()
-		return
-	}
-	done := make(chan struct{})
-	m.waiting = append(m.waiting, waiting{expected: s, done: done})
-	m.callsMutex.Unlock()
-	<-done
-}
-
-// clockTimer represents an object with an associated start time.
-type clockTimer interface {
-	Next() time.Time
-	Tick(time.Time)
-}
-
-// clockTimers represents a list of sortable timers.
-type clockTimers []clockTimer
-
-func (a clockTimers) Len() int           { return len(a) }
-func (a clockTimers) Swap(i, j int)      { a[i], a[j] = a[j], a[i] }
-func (a clockTimers) Less(i, j int) bool { return a[i].Next().Before(a[j].Next()) }
-
-// Timer represents a single event.
-// The current time will be sent on C, unless the timer was created by AfterFunc.
-type Timer struct {
-	C     <-chan time.Time
-	c     chan time.Time
-	timer *time.Timer // realtime impl, if set
-	next  time.Time   // next tick time
-	mock  *Mock       // mock clock, if set
-	fn    func()      // AfterFunc function, if set
-}
-
-// Stop turns off the ticker.
-func (t *Timer) Stop() {
-	if t.timer != nil {
-		t.timer.Stop()
-	} else {
-		t.mock.removeClockTimer((*internalTimer)(t))
-	}
-}
-
-type internalTimer Timer
-
-func (t *internalTimer) Next() time.Time { return t.next }
-func (t *internalTimer) Tick(now time.Time) {
-	if t.fn != nil {
-		t.fn()
-	} else {
-		t.c <- now
-	}
-	t.mock.removeClockTimer((*internalTimer)(t))
-	gosched()
-}
-
-// Ticker holds a channel that receives "ticks" at regular intervals.
-type Ticker struct {
-	C      <-chan time.Time
-	c      chan time.Time
-	ticker *time.Ticker  // realtime impl, if set
-	next   time.Time     // next tick time
-	mock   *Mock         // mock clock, if set
-	d      time.Duration // time between ticks
-}
-
-// Stop turns off the ticker.
-func (t *Ticker) Stop() {
-	if t.ticker != nil {
-		t.ticker.Stop()
-	} else {
-		t.mock.removeClockTimer((*internalTicker)(t))
-	}
-}
-
-type internalTicker Ticker
-
-func (t *internalTicker) Next() time.Time { return t.next }
-func (t *internalTicker) Tick(now time.Time) {
-	select {
-	case t.c <- now:
-	case <-time.After(1 * time.Millisecond):
-	}
-	t.next = now.Add(t.d)
-	gosched()
-}
-
-// Sleep momentarily so that other goroutines can process.
-func gosched() { runtime.Gosched() }
-
-// Calls keeps track of the count of calls for each of the methods on the Clock
-// interface.
-type Calls struct {
-	After     uint32
-	AfterFunc uint32
-	Now       uint32
-	Sleep     uint32
-	Tick      uint32
-	Ticker    uint32
-	Timer     uint32
-}
-
-// atLeast returns true if at least the number of calls in o have been made.
-func (c Calls) atLeast(o Calls) bool {
-	if c.After < o.After {
-		return false
-	}
-	if c.AfterFunc < o.AfterFunc {
-		return false
-	}
-	if c.Now < o.Now {
-		return false
-	}
-	if c.Sleep < o.Sleep {
-		return false
-	}
-	if c.Tick < o.Tick {
-		return false
-	}
-	if c.Ticker < o.Ticker {
-		return false
-	}
-	if c.Timer < o.Timer {
-		return false
-	}
-	return true
-}
-
-type waiting struct {
-	expected Calls
-	done     chan struct{}
-}
diff --git a/vendor/github.com/facebookgo/grace/gracehttp/http.go b/vendor/github.com/facebookgo/grace/gracehttp/http.go
deleted file mode 100644
index 4ba8d284c8..0000000000
--- a/vendor/github.com/facebookgo/grace/gracehttp/http.go
+++ /dev/null
@@ -1,186 +0,0 @@
-// Package gracehttp provides easy to use graceful restart
-// functionality for HTTP server.
-package gracehttp
-
-import (
-	"bytes"
-	"crypto/tls"
-	"flag"
-	"fmt"
-	"log"
-	"net"
-	"net/http"
-	"os"
-	"os/signal"
-	"sync"
-	"syscall"
-
-	"github.com/facebookgo/grace/gracenet"
-	"github.com/facebookgo/httpdown"
-)
-
-var (
-	verbose    = flag.Bool("gracehttp.log", true, "Enable logging.")
-	didInherit = os.Getenv("LISTEN_FDS") != ""
-	ppid       = os.Getppid()
-)
-
-// An app contains one or more servers and associated configuration.
-type app struct {
-	servers   []*http.Server
-	http      *httpdown.HTTP
-	net       *gracenet.Net
-	listeners []net.Listener
-	sds       []httpdown.Server
-	errors    chan error
-}
-
-func newApp(servers []*http.Server) *app {
-	return &app{
-		servers:   servers,
-		http:      &httpdown.HTTP{},
-		net:       &gracenet.Net{},
-		listeners: make([]net.Listener, 0, len(servers)),
-		sds:       make([]httpdown.Server, 0, len(servers)),
-
-		// 2x num servers for possible Close or Stop errors + 1 for possible
-		// StartProcess error.
-		errors: make(chan error, 1+(len(servers)*2)),
-	}
-}
-
-func (a *app) listen() error {
-	for _, s := range a.servers {
-		// TODO: default addresses
-		l, err := a.net.Listen("tcp", s.Addr)
-		if err != nil {
-			return err
-		}
-		if s.TLSConfig != nil {
-			l = tls.NewListener(l, s.TLSConfig)
-		}
-		a.listeners = append(a.listeners, l)
-	}
-	return nil
-}
-
-func (a *app) serve() {
-	for i, s := range a.servers {
-		a.sds = append(a.sds, a.http.Serve(s, a.listeners[i]))
-	}
-}
-
-func (a *app) wait() {
-	var wg sync.WaitGroup
-	wg.Add(len(a.sds) * 2) // Wait & Stop
-	go a.signalHandler(&wg)
-	for _, s := range a.sds {
-		go func(s httpdown.Server) {
-			defer wg.Done()
-			if err := s.Wait(); err != nil {
-				a.errors <- err
-			}
-		}(s)
-	}
-	wg.Wait()
-}
-
-func (a *app) term(wg *sync.WaitGroup) {
-	for _, s := range a.sds {
-		go func(s httpdown.Server) {
-			defer wg.Done()
-			if err := s.Stop(); err != nil {
-				a.errors <- err
-			}
-		}(s)
-	}
-}
-
-func (a *app) signalHandler(wg *sync.WaitGroup) {
-	ch := make(chan os.Signal, 10)
-	signal.Notify(ch, syscall.SIGINT, syscall.SIGTERM, syscall.SIGUSR2)
-	for {
-		sig := <-ch
-		switch sig {
-		case syscall.SIGINT, syscall.SIGTERM:
-			// this ensures a subsequent INT/TERM will trigger standard go behaviour of
-			// terminating.
-			signal.Stop(ch)
-			a.term(wg)
-			return
-		case syscall.SIGUSR2:
-			// we only return here if there's an error, otherwise the new process
-			// will send us a TERM when it's ready to trigger the actual shutdown.
-			if _, err := a.net.StartProcess(); err != nil {
-				a.errors <- err
-			}
-		}
-	}
-}
-
-// Serve will serve the given http.Servers and will monitor for signals
-// allowing for graceful termination (SIGTERM) or restart (SIGUSR2).
-func Serve(servers ...*http.Server) error {
-	a := newApp(servers)
-
-	// Acquire Listeners
-	if err := a.listen(); err != nil {
-		return err
-	}
-
-	// Some useful logging.
-	if *verbose {
-		if didInherit {
-			if ppid == 1 {
-				log.Printf("Listening on init activated %s", pprintAddr(a.listeners))
-			} else {
-				const msg = "Graceful handoff of %s with new pid %d and old pid %d"
-				log.Printf(msg, pprintAddr(a.listeners), os.Getpid(), ppid)
-			}
-		} else {
-			const msg = "Serving %s with pid %d"
-			log.Printf(msg, pprintAddr(a.listeners), os.Getpid())
-		}
-	}
-
-	// Start serving.
-	a.serve()
-
-	// Close the parent if we inherited and it wasn't init that started us.
-	if didInherit && ppid != 1 {
-		if err := syscall.Kill(ppid, syscall.SIGTERM); err != nil {
-			return fmt.Errorf("failed to close parent: %s", err)
-		}
-	}
-
-	waitdone := make(chan struct{})
-	go func() {
-		defer close(waitdone)
-		a.wait()
-	}()
-
-	select {
-	case err := <-a.errors:
-		if err == nil {
-			panic("unexpected nil error")
-		}
-		return err
-	case <-waitdone:
-		if *verbose {
-			log.Printf("Exiting pid %d.", os.Getpid())
-		}
-		return nil
-	}
-}
-
-// Used for pretty printing addresses.
-func pprintAddr(listeners []net.Listener) []byte {
-	var out bytes.Buffer
-	for i, l := range listeners {
-		if i != 0 {
-			fmt.Fprint(&out, ", ")
-		}
-		fmt.Fprint(&out, l.Addr())
-	}
-	return out.Bytes()
-}
diff --git a/vendor/github.com/facebookgo/grace/gracenet/net.go b/vendor/github.com/facebookgo/grace/gracenet/net.go
deleted file mode 100644
index a980954a9d..0000000000
--- a/vendor/github.com/facebookgo/grace/gracenet/net.go
+++ /dev/null
@@ -1,252 +0,0 @@
-// Package gracenet provides a family of Listen functions that either open a
-// fresh connection or provide an inherited connection from when the process
-// was started. The behave like their counterparts in the net package, but
-// transparently provide support for graceful restarts without dropping
-// connections. This is provided in a systemd socket activation compatible form
-// to allow using socket activation.
-//
-// BUG: Doesn't handle closing of listeners.
-package gracenet
-
-import (
-	"fmt"
-	"net"
-	"os"
-	"os/exec"
-	"strconv"
-	"strings"
-	"sync"
-)
-
-const (
-	// Used to indicate a graceful restart in the new process.
-	envCountKey       = "LISTEN_FDS"
-	envCountKeyPrefix = envCountKey + "="
-)
-
-// In order to keep the working directory the same as when we started we record
-// it at startup.
-var originalWD, _ = os.Getwd()
-
-// Net provides the family of Listen functions and maintains the associated
-// state. Typically you will have only once instance of Net per application.
-type Net struct {
-	inherited   []net.Listener
-	active      []net.Listener
-	mutex       sync.Mutex
-	inheritOnce sync.Once
-
-	// used in tests to override the default behavior of starting from fd 3.
-	fdStart int
-}
-
-func (n *Net) inherit() error {
-	var retErr error
-	n.inheritOnce.Do(func() {
-		n.mutex.Lock()
-		defer n.mutex.Unlock()
-		countStr := os.Getenv(envCountKey)
-		if countStr == "" {
-			return
-		}
-		count, err := strconv.Atoi(countStr)
-		if err != nil {
-			retErr = fmt.Errorf("found invalid count value: %s=%s", envCountKey, countStr)
-			return
-		}
-
-		// In tests this may be overridden.
-		fdStart := n.fdStart
-		if fdStart == 0 {
-			// In normal operations if we are inheriting, the listeners will begin at
-			// fd 3.
-			fdStart = 3
-		}
-
-		for i := fdStart; i < fdStart+count; i++ {
-			file := os.NewFile(uintptr(i), "listener")
-			l, err := net.FileListener(file)
-			if err != nil {
-				file.Close()
-				retErr = fmt.Errorf("error inheriting socket fd %d: %s", i, err)
-				return
-			}
-			if err := file.Close(); err != nil {
-				retErr = fmt.Errorf("error closing inherited socket fd %d: %s", i, err)
-				return
-			}
-			n.inherited = append(n.inherited, l)
-		}
-	})
-	return retErr
-}
-
-// Listen announces on the local network address laddr. The network net must be
-// a stream-oriented network: "tcp", "tcp4", "tcp6", "unix" or "unixpacket". It
-// returns an inherited net.Listener for the matching network and address, or
-// creates a new one using net.Listen.
-func (n *Net) Listen(nett, laddr string) (net.Listener, error) {
-	switch nett {
-	default:
-		return nil, net.UnknownNetworkError(nett)
-	case "tcp", "tcp4", "tcp6":
-		addr, err := net.ResolveTCPAddr(nett, laddr)
-		if err != nil {
-			return nil, err
-		}
-		return n.ListenTCP(nett, addr)
-	case "unix", "unixpacket", "invalid_unix_net_for_test":
-		addr, err := net.ResolveUnixAddr(nett, laddr)
-		if err != nil {
-			return nil, err
-		}
-		return n.ListenUnix(nett, addr)
-	}
-}
-
-// ListenTCP announces on the local network address laddr. The network net must
-// be: "tcp", "tcp4" or "tcp6". It returns an inherited net.Listener for the
-// matching network and address, or creates a new one using net.ListenTCP.
-func (n *Net) ListenTCP(nett string, laddr *net.TCPAddr) (*net.TCPListener, error) {
-	if err := n.inherit(); err != nil {
-		return nil, err
-	}
-
-	n.mutex.Lock()
-	defer n.mutex.Unlock()
-
-	// look for an inherited listener
-	for i, l := range n.inherited {
-		if l == nil { // we nil used inherited listeners
-			continue
-		}
-		if isSameAddr(l.Addr(), laddr) {
-			n.inherited[i] = nil
-			n.active = append(n.active, l)
-			return l.(*net.TCPListener), nil
-		}
-	}
-
-	// make a fresh listener
-	l, err := net.ListenTCP(nett, laddr)
-	if err != nil {
-		return nil, err
-	}
-	n.active = append(n.active, l)
-	return l, nil
-}
-
-// ListenUnix announces on the local network address laddr. The network net
-// must be a: "unix" or "unixpacket". It returns an inherited net.Listener for
-// the matching network and address, or creates a new one using net.ListenUnix.
-func (n *Net) ListenUnix(nett string, laddr *net.UnixAddr) (*net.UnixListener, error) {
-	if err := n.inherit(); err != nil {
-		return nil, err
-	}
-
-	n.mutex.Lock()
-	defer n.mutex.Unlock()
-
-	// look for an inherited listener
-	for i, l := range n.inherited {
-		if l == nil { // we nil used inherited listeners
-			continue
-		}
-		if isSameAddr(l.Addr(), laddr) {
-			n.inherited[i] = nil
-			n.active = append(n.active, l)
-			return l.(*net.UnixListener), nil
-		}
-	}
-
-	// make a fresh listener
-	l, err := net.ListenUnix(nett, laddr)
-	if err != nil {
-		return nil, err
-	}
-	n.active = append(n.active, l)
-	return l, nil
-}
-
-// activeListeners returns a snapshot copy of the active listeners.
-func (n *Net) activeListeners() ([]net.Listener, error) {
-	n.mutex.Lock()
-	defer n.mutex.Unlock()
-	ls := make([]net.Listener, len(n.active))
-	copy(ls, n.active)
-	return ls, nil
-}
-
-func isSameAddr(a1, a2 net.Addr) bool {
-	if a1.Network() != a2.Network() {
-		return false
-	}
-	a1s := a1.String()
-	a2s := a2.String()
-	if a1s == a2s {
-		return true
-	}
-
-	// This allows for ipv6 vs ipv4 local addresses to compare as equal. This
-	// scenario is common when listening on localhost.
-	const ipv6prefix = "[::]"
-	a1s = strings.TrimPrefix(a1s, ipv6prefix)
-	a2s = strings.TrimPrefix(a2s, ipv6prefix)
-	const ipv4prefix = "0.0.0.0"
-	a1s = strings.TrimPrefix(a1s, ipv4prefix)
-	a2s = strings.TrimPrefix(a2s, ipv4prefix)
-	return a1s == a2s
-}
-
-// StartProcess starts a new process passing it the active listeners. It
-// doesn't fork, but starts a new process using the same environment and
-// arguments as when it was originally started. This allows for a newly
-// deployed binary to be started. It returns the pid of the newly started
-// process when successful.
-func (n *Net) StartProcess() (int, error) {
-	listeners, err := n.activeListeners()
-	if err != nil {
-		return 0, err
-	}
-
-	// Extract the fds from the listeners.
-	files := make([]*os.File, len(listeners))
-	for i, l := range listeners {
-		files[i], err = l.(filer).File()
-		if err != nil {
-			return 0, err
-		}
-		defer files[i].Close()
-	}
-
-	// Use the original binary location. This works with symlinks such that if
-	// the file it points to has been changed we will use the updated symlink.
-	argv0, err := exec.LookPath(os.Args[0])
-	if err != nil {
-		return 0, err
-	}
-
-	// Pass on the environment and replace the old count key with the new one.
-	var env []string
-	for _, v := range os.Environ() {
-		if !strings.HasPrefix(v, envCountKeyPrefix) {
-			env = append(env, v)
-		}
-	}
-	env = append(env, fmt.Sprintf("%s%d", envCountKeyPrefix, len(listeners)))
-
-	allFiles := append([]*os.File{os.Stdin, os.Stdout, os.Stderr}, files...)
-	process, err := os.StartProcess(argv0, os.Args, &os.ProcAttr{
-		Dir:   originalWD,
-		Env:   env,
-		Files: allFiles,
-	})
-	if err != nil {
-		return 0, err
-	}
-	return process.Pid, nil
-}
-
-type filer interface {
-	File() (*os.File, error)
-}
diff --git a/vendor/github.com/facebookgo/httpdown/.travis.yml b/vendor/github.com/facebookgo/httpdown/.travis.yml
deleted file mode 100644
index ea316cfe50..0000000000
--- a/vendor/github.com/facebookgo/httpdown/.travis.yml
+++ /dev/null
@@ -1,23 +0,0 @@
-language: go
-
-go:
-  - 1.6
-
-before_install:
-  - go get -v golang.org/x/tools/cmd/vet
-  - go get -v golang.org/x/tools/cmd/cover
-  - go get -v github.com/golang/lint/golint
-
-install:
-  - go install -race -v std
-  - go get -race -t -v ./...
-  - go install -race -v ./...
-
-script:
-  - go vet ./...
-  - $HOME/gopath/bin/golint .
-  - go test -cpu=2 -race -v ./...
-  - go test -cpu=2 -covermode=atomic -coverprofile=coverage.txt ./
-
-after_success:
-  - bash <(curl -s https://codecov.io/bash)
diff --git a/vendor/github.com/facebookgo/httpdown/httpdown.go b/vendor/github.com/facebookgo/httpdown/httpdown.go
deleted file mode 100644
index 34c5dea9ff..0000000000
--- a/vendor/github.com/facebookgo/httpdown/httpdown.go
+++ /dev/null
@@ -1,376 +0,0 @@
-// Package httpdown provides http.ConnState enabled graceful termination of
-// http.Server.
-package httpdown
-
-import (
-	"crypto/tls"
-	"fmt"
-	"net"
-	"net/http"
-	"os"
-	"os/signal"
-	"sync"
-	"syscall"
-	"time"
-
-	"github.com/facebookgo/clock"
-	"github.com/facebookgo/stats"
-)
-
-const (
-	defaultStopTimeout = time.Minute
-	defaultKillTimeout = time.Minute
-)
-
-// A Server allows encapsulates the process of accepting new connections and
-// serving them, and gracefully shutting down the listener without dropping
-// active connections.
-type Server interface {
-	// Wait waits for the serving loop to finish. This will happen when Stop is
-	// called, at which point it returns no error, or if there is an error in the
-	// serving loop. You must call Wait after calling Serve or ListenAndServe.
-	Wait() error
-
-	// Stop stops the listener. It will block until all connections have been
-	// closed.
-	Stop() error
-}
-
-// HTTP defines the configuration for serving a http.Server. Multiple calls to
-// Serve or ListenAndServe can be made on the same HTTP instance. The default
-// timeouts of 1 minute each result in a maximum of 2 minutes before a Stop()
-// returns.
-type HTTP struct {
-	// StopTimeout is the duration before we begin force closing connections.
-	// Defaults to 1 minute.
-	StopTimeout time.Duration
-
-	// KillTimeout is the duration before which we completely give up and abort
-	// even though we still have connected clients. This is useful when a large
-	// number of client connections exist and closing them can take a long time.
-	// Note, this is in addition to the StopTimeout. Defaults to 1 minute.
-	KillTimeout time.Duration
-
-	// Stats is optional. If provided, it will be used to record various metrics.
-	Stats stats.Client
-
-	// Clock allows for testing timing related functionality. Do not specify this
-	// in production code.
-	Clock clock.Clock
-}
-
-// Serve provides the low-level API which is useful if you're creating your own
-// net.Listener.
-func (h HTTP) Serve(s *http.Server, l net.Listener) Server {
-	stopTimeout := h.StopTimeout
-	if stopTimeout == 0 {
-		stopTimeout = defaultStopTimeout
-	}
-	killTimeout := h.KillTimeout
-	if killTimeout == 0 {
-		killTimeout = defaultKillTimeout
-	}
-	klock := h.Clock
-	if klock == nil {
-		klock = clock.New()
-	}
-
-	ss := &server{
-		stopTimeout:  stopTimeout,
-		killTimeout:  killTimeout,
-		stats:        h.Stats,
-		clock:        klock,
-		oldConnState: s.ConnState,
-		listener:     l,
-		server:       s,
-		serveDone:    make(chan struct{}),
-		serveErr:     make(chan error, 1),
-		new:          make(chan net.Conn),
-		active:       make(chan net.Conn),
-		idle:         make(chan net.Conn),
-		closed:       make(chan net.Conn),
-		stop:         make(chan chan struct{}),
-		kill:         make(chan chan struct{}),
-	}
-	s.ConnState = ss.connState
-	go ss.manage()
-	go ss.serve()
-	return ss
-}
-
-// ListenAndServe returns a Server for the given http.Server. It is equivalent
-// to ListenAndServe from the standard library, but returns immediately.
-// Requests will be accepted in a background goroutine. If the http.Server has
-// a non-nil TLSConfig, a TLS enabled listener will be setup.
-func (h HTTP) ListenAndServe(s *http.Server) (Server, error) {
-	addr := s.Addr
-	if addr == "" {
-		if s.TLSConfig == nil {
-			addr = ":http"
-		} else {
-			addr = ":https"
-		}
-	}
-	l, err := net.Listen("tcp", addr)
-	if err != nil {
-		stats.BumpSum(h.Stats, "listen.error", 1)
-		return nil, err
-	}
-	if s.TLSConfig != nil {
-		l = tls.NewListener(l, s.TLSConfig)
-	}
-	return h.Serve(s, l), nil
-}
-
-// server manages the serving process and allows for gracefully stopping it.
-type server struct {
-	stopTimeout time.Duration
-	killTimeout time.Duration
-	stats       stats.Client
-	clock       clock.Clock
-
-	oldConnState func(net.Conn, http.ConnState)
-	server       *http.Server
-	serveDone    chan struct{}
-	serveErr     chan error
-	listener     net.Listener
-
-	new    chan net.Conn
-	active chan net.Conn
-	idle   chan net.Conn
-	closed chan net.Conn
-	stop   chan chan struct{}
-	kill   chan chan struct{}
-
-	stopOnce sync.Once
-	stopErr  error
-}
-
-func (s *server) connState(c net.Conn, cs http.ConnState) {
-	if s.oldConnState != nil {
-		s.oldConnState(c, cs)
-	}
-
-	switch cs {
-	case http.StateNew:
-		s.new <- c
-	case http.StateActive:
-		s.active <- c
-	case http.StateIdle:
-		s.idle <- c
-	case http.StateHijacked, http.StateClosed:
-		s.closed <- c
-	}
-}
-
-func (s *server) manage() {
-	defer func() {
-		close(s.new)
-		close(s.active)
-		close(s.idle)
-		close(s.closed)
-		close(s.stop)
-		close(s.kill)
-	}()
-
-	var stopDone chan struct{}
-
-	conns := map[net.Conn]http.ConnState{}
-	var countNew, countActive, countIdle float64
-
-	// decConn decrements the count associated with the current state of the
-	// given connection.
-	decConn := func(c net.Conn) {
-		switch conns[c] {
-		default:
-			panic(fmt.Errorf("unknown existing connection: %s", c))
-		case http.StateNew:
-			countNew--
-		case http.StateActive:
-			countActive--
-		case http.StateIdle:
-			countIdle--
-		}
-	}
-
-	// setup a ticker to report various values every minute. if we don't have a
-	// Stats implementation provided, we Stop it so it never ticks.
-	statsTicker := s.clock.Ticker(time.Minute)
-	if s.stats == nil {
-		statsTicker.Stop()
-	}
-
-	for {
-		select {
-		case <-statsTicker.C:
-			// we'll only get here when s.stats is not nil
-			s.stats.BumpAvg("http-state.new", countNew)
-			s.stats.BumpAvg("http-state.active", countActive)
-			s.stats.BumpAvg("http-state.idle", countIdle)
-			s.stats.BumpAvg("http-state.total", countNew+countActive+countIdle)
-		case c := <-s.new:
-			conns[c] = http.StateNew
-			countNew++
-		case c := <-s.active:
-			decConn(c)
-			countActive++
-
-			conns[c] = http.StateActive
-		case c := <-s.idle:
-			decConn(c)
-			countIdle++
-
-			conns[c] = http.StateIdle
-
-			// if we're already stopping, close it
-			if stopDone != nil {
-				c.Close()
-			}
-		case c := <-s.closed:
-			stats.BumpSum(s.stats, "conn.closed", 1)
-			decConn(c)
-			delete(conns, c)
-
-			// if we're waiting to stop and are all empty, we just closed the last
-			// connection and we're done.
-			if stopDone != nil && len(conns) == 0 {
-				close(stopDone)
-				return
-			}
-		case stopDone = <-s.stop:
-			// if we're already all empty, we're already done
-			if len(conns) == 0 {
-				close(stopDone)
-				return
-			}
-
-			// close current idle connections right away
-			for c, cs := range conns {
-				if cs == http.StateIdle {
-					c.Close()
-				}
-			}
-
-			// continue the loop and wait for all the ConnState updates which will
-			// eventually close(stopDone) and return from this goroutine.
-
-		case killDone := <-s.kill:
-			// force close all connections
-			stats.BumpSum(s.stats, "kill.conn.count", float64(len(conns)))
-			for c := range conns {
-				c.Close()
-			}
-
-			// don't block the kill.
-			close(killDone)
-
-			// continue the loop and we wait for all the ConnState updates and will
-			// return from this goroutine when we're all done. otherwise we'll try to
-			// send those ConnState updates on closed channels.
-
-		}
-	}
-}
-
-func (s *server) serve() {
-	stats.BumpSum(s.stats, "serve", 1)
-	s.serveErr <- s.server.Serve(s.listener)
-	close(s.serveDone)
-	close(s.serveErr)
-}
-
-func (s *server) Wait() error {
-	if err := <-s.serveErr; !isUseOfClosedError(err) {
-		return err
-	}
-	return nil
-}
-
-func (s *server) Stop() error {
-	s.stopOnce.Do(func() {
-		defer stats.BumpTime(s.stats, "stop.time").End()
-		stats.BumpSum(s.stats, "stop", 1)
-
-		// first disable keep-alive for new connections
-		s.server.SetKeepAlivesEnabled(false)
-
-		// then close the listener so new connections can't connect come thru
-		closeErr := s.listener.Close()
-		<-s.serveDone
-
-		// then trigger the background goroutine to stop and wait for it
-		stopDone := make(chan struct{})
-		s.stop <- stopDone
-
-		// wait for stop
-		select {
-		case <-stopDone:
-		case <-s.clock.After(s.stopTimeout):
-			defer stats.BumpTime(s.stats, "kill.time").End()
-			stats.BumpSum(s.stats, "kill", 1)
-
-			// stop timed out, wait for kill
-			killDone := make(chan struct{})
-			s.kill <- killDone
-			select {
-			case <-killDone:
-			case <-s.clock.After(s.killTimeout):
-				// kill timed out, give up
-				stats.BumpSum(s.stats, "kill.timeout", 1)
-			}
-		}
-
-		if closeErr != nil && !isUseOfClosedError(closeErr) {
-			stats.BumpSum(s.stats, "listener.close.error", 1)
-			s.stopErr = closeErr
-		}
-	})
-	return s.stopErr
-}
-
-func isUseOfClosedError(err error) bool {
-	if err == nil {
-		return false
-	}
-	if opErr, ok := err.(*net.OpError); ok {
-		err = opErr.Err
-	}
-	return err.Error() == "use of closed network connection"
-}
-
-// ListenAndServe is a convenience function to serve and wait for a SIGTERM
-// or SIGINT before shutting down.
-func ListenAndServe(s *http.Server, hd *HTTP) error {
-	if hd == nil {
-		hd = &HTTP{}
-	}
-	hs, err := hd.ListenAndServe(s)
-	if err != nil {
-		return err
-	}
-
-	waiterr := make(chan error, 1)
-	go func() {
-		defer close(waiterr)
-		waiterr <- hs.Wait()
-	}()
-
-	signals := make(chan os.Signal, 10)
-	signal.Notify(signals, syscall.SIGTERM, syscall.SIGINT)
-
-	select {
-	case err := <-waiterr:
-		if err != nil {
-			return err
-		}
-	case <-signals:
-		signal.Stop(signals)
-		if err := hs.Stop(); err != nil {
-			return err
-		}
-		if err := <-waiterr; err != nil {
-			return err
-		}
-	}
-	return nil
-}
diff --git a/vendor/github.com/facebookgo/httpdown/license b/vendor/github.com/facebookgo/httpdown/license
deleted file mode 100644
index d849082ffb..0000000000
--- a/vendor/github.com/facebookgo/httpdown/license
+++ /dev/null
@@ -1,30 +0,0 @@
-BSD License
-
-For httpdown software
-
-Copyright (c) 2015, Facebook, Inc. All rights reserved.
-
-Redistribution and use in source and binary forms, with or without modification,
-are permitted provided that the following conditions are met:
-
- * Redistributions of source code must retain the above copyright notice, this
-   list of conditions and the following disclaimer.
-
- * Redistributions in binary form must reproduce the above copyright notice,
-   this list of conditions and the following disclaimer in the documentation
-   and/or other materials provided with the distribution.
-
- * Neither the name Facebook nor the names of its contributors may be used to
-   endorse or promote products derived from this software without specific
-   prior written permission.
-
-THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
-ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
-WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
-DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
-ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
-(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
-LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
-ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
-SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
diff --git a/vendor/github.com/facebookgo/httpdown/patents b/vendor/github.com/facebookgo/httpdown/patents
deleted file mode 100644
index f7133456a2..0000000000
--- a/vendor/github.com/facebookgo/httpdown/patents
+++ /dev/null
@@ -1,33 +0,0 @@
-Additional Grant of Patent Rights Version 2
-
-"Software" means the httpdown software distributed by Facebook, Inc.
-
-Facebook, Inc. ("Facebook") hereby grants to each recipient of the Software
-("you") a perpetual, worldwide, royalty-free, non-exclusive, irrevocable
-(subject to the termination provision below) license under any Necessary
-Claims, to make, have made, use, sell, offer to sell, import, and otherwise
-transfer the Software. For avoidance of doubt, no license is granted under
-Facebook’s rights in any patent claims that are infringed by (i) modifications
-to the Software made by you or any third party or (ii) the Software in
-combination with any software or other technology.
-
-The license granted hereunder will terminate, automatically and without notice,
-if you (or any of your subsidiaries, corporate affiliates or agents) initiate
-directly or indirectly, or take a direct financial interest in, any Patent
-Assertion: (i) against Facebook or any of its subsidiaries or corporate
-affiliates, (ii) against any party if such Patent Assertion arises in whole or
-in part from any software, technology, product or service of Facebook or any of
-its subsidiaries or corporate affiliates, or (iii) against any party relating
-to the Software. Notwithstanding the foregoing, if Facebook or any of its
-subsidiaries or corporate affiliates files a lawsuit alleging patent
-infringement against you in the first instance, and you respond by filing a
-patent infringement counterclaim in that lawsuit against that party that is
-unrelated to the Software, the license granted hereunder will not terminate
-under section (i) of this paragraph due to such counterclaim.
-
-A "Necessary Claim" is a claim of a patent owned by Facebook that is
-necessarily infringed by the Software standing alone.
-
-A "Patent Assertion" is any lawsuit or other action alleging direct, indirect,
-or contributory infringement or inducement to infringe any patent, including a
-cross-claim or counterclaim.
diff --git a/vendor/github.com/facebookgo/httpdown/readme.md b/vendor/github.com/facebookgo/httpdown/readme.md
deleted file mode 100644
index d5fa245dbc..0000000000
--- a/vendor/github.com/facebookgo/httpdown/readme.md
+++ /dev/null
@@ -1,41 +0,0 @@
-httpdown [![Build Status](https://secure.travis-ci.org/facebookgo/httpdown.png)](https://travis-ci.org/facebookgo/httpdown)
-========
-
-Documentation: https://godoc.org/github.com/facebookgo/httpdown
-
-Package httpdown provides a library that makes it easy to build a HTTP server
-that can be shutdown gracefully (that is, without dropping any connections).
-
-If you want graceful restart and not just graceful shutdown, look at the
-[grace](https://github.com/facebookgo/grace) package which uses this package
-underneath but also provides graceful restart.
-
-Usage
------
-
-Demo HTTP Server with graceful termination:
-https://github.com/facebookgo/httpdown/blob/master/httpdown_example/main.go
-
-1. Install the demo application
-
-        go get github.com/facebookgo/httpdown/httpdown_example
-
-1. Start it in the first terminal
-
-        httpdown_example
-
-   This will output something like:
-
-        2014/11/18 21:57:50 serving on http://127.0.0.1:8080/ with pid 17
-
-1. In a second terminal start a slow HTTP request
-
-        curl 'http://localhost:8080/?duration=20s'
-
-1. In a third terminal trigger a graceful shutdown (using the pid from your output):
-
-        kill -TERM 17
-
-This will demonstrate that the slow request was served before the server was
-shutdown. You could also have used `Ctrl-C` instead of `kill` as the example
-application triggers graceful shutdown on TERM or INT signals.
diff --git a/vendor/github.com/facebookgo/stats/.travis.yml b/vendor/github.com/facebookgo/stats/.travis.yml
deleted file mode 100644
index 9c9f036ae3..0000000000
--- a/vendor/github.com/facebookgo/stats/.travis.yml
+++ /dev/null
@@ -1,20 +0,0 @@
-language: go
-
-go:
-  - 1.5
-
-before_install:
-  - go get -v golang.org/x/tools/cmd/vet
-  - go get -v golang.org/x/tools/cmd/cover
-  - go get -v github.com/golang/lint/golint
-
-install:
-  - go install -race -v std
-  - go get -race -t -v ./...
-  - go install -race -v ./...
-
-script:
-  - go vet ./...
-  - $HOME/gopath/bin/golint .
-  - go test -cpu=2 -race -v ./...
-  - go test -cpu=2 -covermode=atomic ./...
diff --git a/vendor/github.com/facebookgo/stats/aggregation.go b/vendor/github.com/facebookgo/stats/aggregation.go
deleted file mode 100644
index 8f57fb7f1b..0000000000
--- a/vendor/github.com/facebookgo/stats/aggregation.go
+++ /dev/null
@@ -1,35 +0,0 @@
-package stats
-
-import "sort"
-
-// Average returns the average value
-func Average(values []float64) float64 {
-	if len(values) == 0 {
-		return 0
-	}
-
-	var val float64
-	for _, point := range values {
-		val += point
-	}
-	return val / float64(len(values))
-}
-
-// Sum returns the sum of all the given values
-func Sum(values []float64) float64 {
-	var val float64
-	for _, point := range values {
-		val += point
-	}
-	return val
-}
-
-// Percentiles returns a map containing the asked for percentiles
-func Percentiles(values []float64, percentiles map[string]float64) map[string]float64 {
-	sort.Float64s(values)
-	results := map[string]float64{}
-	for label, p := range percentiles {
-		results[label] = values[int(float64(len(values))*p)]
-	}
-	return results
-}
diff --git a/vendor/github.com/facebookgo/stats/counter.go b/vendor/github.com/facebookgo/stats/counter.go
deleted file mode 100644
index 59a0ed1e7d..0000000000
--- a/vendor/github.com/facebookgo/stats/counter.go
+++ /dev/null
@@ -1,112 +0,0 @@
-package stats
-
-import "fmt"
-
-// Type is the type of aggregation of apply
-type Type int
-
-const (
-	AggregateAvg Type = iota
-	AggregateSum
-	AggregateHistogram
-)
-
-var (
-	// HistogramPercentiles is used to determine which percentiles to return for
-	// SimpleCounter.Aggregate
-	HistogramPercentiles = map[string]float64{
-		"p50": 0.5,
-		"p95": 0.95,
-		"p99": 0.99,
-	}
-
-	// MinSamplesForPercentiles is used by SimpleCounter.Aggregate to determine
-	// what the minimum number of samples is required for percentile analysis
-	MinSamplesForPercentiles = 10
-)
-
-// Aggregates can be used to merge counters together. This is not goroutine safe
-type Aggregates map[string]Counter
-
-// Add adds the counter for aggregation. This is not goroutine safe
-func (a Aggregates) Add(c Counter) error {
-	key := c.FullKey()
-	if counter, ok := a[key]; ok {
-		if counter.GetType() != c.GetType() {
-			return fmt.Errorf("stats: mismatched aggregation type for: %s", key)
-		}
-		counter.AddValues(c.GetValues()...)
-	} else {
-		a[key] = c
-	}
-	return nil
-}
-
-// Counter is the interface used by Aggregates to merge counters together
-type Counter interface {
-	// FullKey is used to uniquely identify the counter
-	FullKey() string
-
-	// AddValues adds values for aggregation
-	AddValues(...float64)
-
-	// GetValues returns the values for aggregation
-	GetValues() []float64
-
-	// GetType returns the type of aggregation to apply
-	GetType() Type
-}
-
-// SimpleCounter is a basic implementation of the Counter interface
-type SimpleCounter struct {
-	Key    string
-	Values []float64
-	Type   Type
-}
-
-// FullKey is part of the Counter interace
-func (s *SimpleCounter) FullKey() string {
-	return s.Key
-}
-
-// GetValues is part of the Counter interface
-func (s *SimpleCounter) GetValues() []float64 {
-	return s.Values
-}
-
-// AddValues is part of the Counter interface
-func (s *SimpleCounter) AddValues(vs ...float64) {
-	s.Values = append(s.Values, vs...)
-}
-
-// GetType is part of the Counter interface
-func (s *SimpleCounter) GetType() Type {
-	return s.Type
-}
-
-// Aggregate aggregates the provided values appropriately, returning a map
-// from key to value. If AggregateHistogram is specified, the map will contain
-// the relevant percentiles as specified by HistogramPercentiles
-func (s *SimpleCounter) Aggregate() map[string]float64 {
-	switch s.Type {
-	case AggregateAvg:
-		return map[string]float64{
-			s.Key: Average(s.Values),
-		}
-	case AggregateSum:
-		return map[string]float64{
-			s.Key: Sum(s.Values),
-		}
-	case AggregateHistogram:
-		histogram := map[string]float64{
-			s.Key: Average(s.Values),
-		}
-		if len(s.Values) > MinSamplesForPercentiles {
-			for k, v := range Percentiles(s.Values, HistogramPercentiles) {
-				histogram[fmt.Sprintf("%s.%s", s.Key, k)] = v
-			}
-		}
-		return histogram
-	}
-	panic("stats: unsupported aggregation type")
-}
diff --git a/vendor/github.com/facebookgo/stats/license b/vendor/github.com/facebookgo/stats/license
deleted file mode 100644
index feae870756..0000000000
--- a/vendor/github.com/facebookgo/stats/license
+++ /dev/null
@@ -1,30 +0,0 @@
-BSD License
-
-For stats software
-
-Copyright (c) 2015, Facebook, Inc. All rights reserved.
-
-Redistribution and use in source and binary forms, with or without modification,
-are permitted provided that the following conditions are met:
-
- * Redistributions of source code must retain the above copyright notice, this
-   list of conditions and the following disclaimer.
-
- * Redistributions in binary form must reproduce the above copyright notice,
-   this list of conditions and the following disclaimer in the documentation
-   and/or other materials provided with the distribution.
-
- * Neither the name Facebook nor the names of its contributors may be used to
-   endorse or promote products derived from this software without specific
-   prior written permission.
-
-THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
-ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
-WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
-DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
-ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
-(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
-LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
-ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
-SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
diff --git a/vendor/github.com/facebookgo/stats/patents b/vendor/github.com/facebookgo/stats/patents
deleted file mode 100644
index 5d76172129..0000000000
--- a/vendor/github.com/facebookgo/stats/patents
+++ /dev/null
@@ -1,33 +0,0 @@
-Additional Grant of Patent Rights Version 2
-
-"Software" means the stats software distributed by Facebook, Inc.
-
-Facebook, Inc. ("Facebook") hereby grants to each recipient of the Software
-("you") a perpetual, worldwide, royalty-free, non-exclusive, irrevocable
-(subject to the termination provision below) license under any Necessary
-Claims, to make, have made, use, sell, offer to sell, import, and otherwise
-transfer the Software. For avoidance of doubt, no license is granted under
-Facebook’s rights in any patent claims that are infringed by (i) modifications
-to the Software made by you or any third party or (ii) the Software in
-combination with any software or other technology.
-
-The license granted hereunder will terminate, automatically and without notice,
-if you (or any of your subsidiaries, corporate affiliates or agents) initiate
-directly or indirectly, or take a direct financial interest in, any Patent
-Assertion: (i) against Facebook or any of its subsidiaries or corporate
-affiliates, (ii) against any party if such Patent Assertion arises in whole or
-in part from any software, technology, product or service of Facebook or any of
-its subsidiaries or corporate affiliates, or (iii) against any party relating
-to the Software. Notwithstanding the foregoing, if Facebook or any of its
-subsidiaries or corporate affiliates files a lawsuit alleging patent
-infringement against you in the first instance, and you respond by filing a
-patent infringement counterclaim in that lawsuit against that party that is
-unrelated to the Software, the license granted hereunder will not terminate
-under section (i) of this paragraph due to such counterclaim.
-
-A "Necessary Claim" is a claim of a patent owned by Facebook that is
-necessarily infringed by the Software standing alone.
-
-A "Patent Assertion" is any lawsuit or other action alleging direct, indirect,
-or contributory infringement or inducement to infringe any patent, including a
-cross-claim or counterclaim.
diff --git a/vendor/github.com/facebookgo/stats/readme.md b/vendor/github.com/facebookgo/stats/readme.md
deleted file mode 100644
index f268ed307b..0000000000
--- a/vendor/github.com/facebookgo/stats/readme.md
+++ /dev/null
@@ -1,4 +0,0 @@
-stats [![Build Status](https://secure.travis-ci.org/facebookgo/stats.png)](https://travis-ci.org/facebookgo/stats)
-=====
-
-Documentation: https://godoc.org/github.com/facebookgo/stats
diff --git a/vendor/github.com/facebookgo/stats/stats.go b/vendor/github.com/facebookgo/stats/stats.go
deleted file mode 100644
index b833506aa2..0000000000
--- a/vendor/github.com/facebookgo/stats/stats.go
+++ /dev/null
@@ -1,166 +0,0 @@
-// Package stats defines a lightweight interface for collecting statistics. It
-// doesn't provide an implementation, just the shared interface.
-package stats
-
-// Client provides methods to collection statistics.
-type Client interface {
-	// BumpAvg bumps the average for the given key.
-	BumpAvg(key string, val float64)
-
-	// BumpSum bumps the sum for the given key.
-	BumpSum(key string, val float64)
-
-	// BumpHistogram bumps the histogram for the given key.
-	BumpHistogram(key string, val float64)
-
-	// BumpTime is a special version of BumpHistogram which is specialized for
-	// timers. Calling it starts the timer, and it returns a value on which End()
-	// can be called to indicate finishing the timer. A convenient way of
-	// recording the duration of a function is calling it like such at the top of
-	// the function:
-	//
-	//     defer s.BumpTime("my.function").End()
-	BumpTime(key string) interface {
-		End()
-	}
-}
-
-// PrefixClient adds multiple keys for the same value, with each prefix
-// added to the key and calls the underlying client.
-func PrefixClient(prefixes []string, client Client) Client {
-	return &prefixClient{
-		Prefixes: prefixes,
-		Client:   client,
-	}
-}
-
-type prefixClient struct {
-	Prefixes []string
-	Client   Client
-}
-
-func (p *prefixClient) BumpAvg(key string, val float64) {
-	for _, prefix := range p.Prefixes {
-		p.Client.BumpAvg(prefix+key, val)
-	}
-}
-
-func (p *prefixClient) BumpSum(key string, val float64) {
-	for _, prefix := range p.Prefixes {
-		p.Client.BumpSum(prefix+key, val)
-	}
-}
-
-func (p *prefixClient) BumpHistogram(key string, val float64) {
-	for _, prefix := range p.Prefixes {
-		p.Client.BumpHistogram(prefix+key, val)
-	}
-}
-
-func (p *prefixClient) BumpTime(key string) interface {
-	End()
-} {
-	var m multiEnder
-	for _, prefix := range p.Prefixes {
-		m = append(m, p.Client.BumpTime(prefix+key))
-	}
-	return m
-}
-
-// multiEnder combines many enders together.
-type multiEnder []interface {
-	End()
-}
-
-func (m multiEnder) End() {
-	for _, e := range m {
-		e.End()
-	}
-}
-
-// HookClient is useful for testing. It provides optional hooks for each
-// expected method in the interface, which if provided will be called. If a
-// hook is not provided, it will be ignored.
-type HookClient struct {
-	BumpAvgHook       func(key string, val float64)
-	BumpSumHook       func(key string, val float64)
-	BumpHistogramHook func(key string, val float64)
-	BumpTimeHook      func(key string) interface {
-		End()
-	}
-}
-
-// BumpAvg will call BumpAvgHook if defined.
-func (c *HookClient) BumpAvg(key string, val float64) {
-	if c.BumpAvgHook != nil {
-		c.BumpAvgHook(key, val)
-	}
-}
-
-// BumpSum will call BumpSumHook if defined.
-func (c *HookClient) BumpSum(key string, val float64) {
-	if c.BumpSumHook != nil {
-		c.BumpSumHook(key, val)
-	}
-}
-
-// BumpHistogram will call BumpHistogramHook if defined.
-func (c *HookClient) BumpHistogram(key string, val float64) {
-	if c.BumpHistogramHook != nil {
-		c.BumpHistogramHook(key, val)
-	}
-}
-
-// BumpTime will call BumpTimeHook if defined.
-func (c *HookClient) BumpTime(key string) interface {
-	End()
-} {
-	if c.BumpTimeHook != nil {
-		return c.BumpTimeHook(key)
-	}
-	return NoOpEnd
-}
-
-type noOpEnd struct{}
-
-func (n noOpEnd) End() {}
-
-// NoOpEnd provides a dummy value for use in tests as valid return value for
-// BumpTime().
-var NoOpEnd = noOpEnd{}
-
-// BumpAvg calls BumpAvg on the Client if it isn't nil. This is useful when a
-// component has an optional stats.Client.
-func BumpAvg(c Client, key string, val float64) {
-	if c != nil {
-		c.BumpAvg(key, val)
-	}
-}
-
-// BumpSum calls BumpSum on the Client if it isn't nil. This is useful when a
-// component has an optional stats.Client.
-func BumpSum(c Client, key string, val float64) {
-	if c != nil {
-		c.BumpSum(key, val)
-	}
-}
-
-// BumpHistogram calls BumpHistogram on the Client if it isn't nil. This is
-// useful when a component has an optional stats.Client.
-func BumpHistogram(c Client, key string, val float64) {
-	if c != nil {
-		c.BumpHistogram(key, val)
-	}
-}
-
-// BumpTime calls BumpTime on the Client if it isn't nil. If the Client is nil
-// it still returns a valid return value which will be a no-op. This is useful
-// when a component has an optional stats.Client.
-func BumpTime(c Client, key string) interface {
-	End()
-} {
-	if c != nil {
-		return c.BumpTime(key)
-	}
-	return NoOpEnd
-}
diff --git a/vendor/github.com/facebookgo/stats/stopper.go b/vendor/github.com/facebookgo/stats/stopper.go
deleted file mode 100644
index 38e8eab80a..0000000000
--- a/vendor/github.com/facebookgo/stats/stopper.go
+++ /dev/null
@@ -1,17 +0,0 @@
-package stats
-
-import "time"
-
-// Stopper calls Client.BumpSum and Client.BumpHistogram when End'ed
-type Stopper struct {
-	Key    string
-	Start  time.Time
-	Client Client
-}
-
-// End the Stopper
-func (s *Stopper) End() {
-	since := time.Since(s.Start).Seconds() * 1000.0
-	s.Client.BumpSum(s.Key+".total", since)
-	s.Client.BumpHistogram(s.Key, since)
-}
diff --git a/vendor/modules.txt b/vendor/modules.txt
index 30b1370933..52bb23dfda 100644
--- a/vendor/modules.txt
+++ b/vendor/modules.txt
@@ -132,15 +132,6 @@ github.com/emirpasic/gods/utils
 github.com/etcd-io/bbolt
 # github.com/ethantkoenig/rupture v0.0.0-20180203182544-0a76f03a811a
 github.com/ethantkoenig/rupture
-# github.com/facebookgo/clock v0.0.0-20150410010913-600d898af40a
-github.com/facebookgo/clock
-# github.com/facebookgo/grace v0.0.0-20160926231715-5729e484473f
-github.com/facebookgo/grace/gracehttp
-github.com/facebookgo/grace/gracenet
-# github.com/facebookgo/httpdown v0.0.0-20160323221027-a3b1354551a2
-github.com/facebookgo/httpdown
-# github.com/facebookgo/stats v0.0.0-20151006221625-1b76add642e4
-github.com/facebookgo/stats
 # github.com/fsnotify/fsnotify v1.4.7
 github.com/fsnotify/fsnotify
 # github.com/gliderlabs/ssh v0.2.2