Move mailer to use a queue (#9789)

* Move mailer to use a queue

* Make sectionMap map[string]bool

* Ensure that Message is json encodable

3 files changed, 75 insertions, 46 deletions

diff --git a/services/mailer/mail.go b/services/mailer/mail.go
index 4b8e46715f..3241ae728d 100644
--- a/services/mailer/mail.go
+++ b/services/mailer/mail.go
@@ -51,7 +51,7 @@ func InitMailRender(subjectTpl *texttmpl.Template, bodyTpl *template.Template) {
 
 // SendTestMail sends a test mail
 func SendTestMail(email string) error {
-	return gomail.Send(Sender, NewMessage([]string{email}, "Gitea Test Email!", "Gitea Test Email!").Message)
+	return gomail.Send(Sender, NewMessage([]string{email}, "Gitea Test Email!", "Gitea Test Email!").ToMessage())
 }
 
 // SendUserMail sends a mail to the user
diff --git a/services/mailer/mail_test.go b/services/mailer/mail_test.go
index 43e99c635e..d7d02d9dee 100644
--- a/services/mailer/mail_test.go
+++ b/services/mailer/mail_test.go
@@ -61,11 +61,11 @@ func TestComposeIssueCommentMessage(t *testing.T) {
 	msgs := composeIssueCommentMessages(&mailCommentContext{Issue: issue, Doer: doer, ActionType: models.ActionCommentIssue,
 		Content: "test body", Comment: comment}, tos, false, "issue comment")
 	assert.Len(t, msgs, 2)
-
-	mailto := msgs[0].GetHeader("To")
-	subject := msgs[0].GetHeader("Subject")
-	inreplyTo := msgs[0].GetHeader("In-Reply-To")
-	references := msgs[0].GetHeader("References")
+	gomailMsg := msgs[0].ToMessage()
+	mailto := gomailMsg.GetHeader("To")
+	subject := gomailMsg.GetHeader("Subject")
+	inreplyTo := gomailMsg.GetHeader("In-Reply-To")
+	references := gomailMsg.GetHeader("References")
 
 	assert.Len(t, mailto, 1, "exactly one recipient is expected in the To field")
 	assert.Equal(t, "Re: ", subject[0][:4], "Comment reply subject should contain Re:")
@@ -96,14 +96,15 @@ func TestComposeIssueMessage(t *testing.T) {
 		Content: "test body"}, tos, false, "issue create")
 	assert.Len(t, msgs, 2)
 
-	mailto := msgs[0].GetHeader("To")
-	subject := msgs[0].GetHeader("Subject")
-	messageID := msgs[0].GetHeader("Message-ID")
+	gomailMsg := msgs[0].ToMessage()
+	mailto := gomailMsg.GetHeader("To")
+	subject := gomailMsg.GetHeader("Subject")
+	messageID := gomailMsg.GetHeader("Message-ID")
 
 	assert.Len(t, mailto, 1, "exactly one recipient is expected in the To field")
 	assert.Equal(t, "[user2/repo1] @user2 #1 - issue1", subject[0])
-	assert.Nil(t, msgs[0].GetHeader("In-Reply-To"))
-	assert.Nil(t, msgs[0].GetHeader("References"))
+	assert.Nil(t, gomailMsg.GetHeader("In-Reply-To"))
+	assert.Nil(t, gomailMsg.GetHeader("References"))
 	assert.Equal(t, messageID[0], "<user2/repo1/issues/1@localhost>", "Message-ID header doesn't match")
 }
 
@@ -134,9 +135,9 @@ func TestTemplateSelection(t *testing.T) {
 	InitMailRender(stpl, btpl)
 
 	expect := func(t *testing.T, msg *Message, expSubject, expBody string) {
-		subject := msg.GetHeader("Subject")
+		subject := msg.ToMessage().GetHeader("Subject")
 		msgbuf := new(bytes.Buffer)
-		_, _ = msg.WriteTo(msgbuf)
+		_, _ = msg.ToMessage().WriteTo(msgbuf)
 		wholemsg := msgbuf.String()
 		assert.Equal(t, []string{expSubject}, subject)
 		assert.Contains(t, wholemsg, expBody)
@@ -188,9 +189,9 @@ func TestTemplateServices(t *testing.T) {
 		msg := testComposeIssueCommentMessage(t, &mailCommentContext{Issue: issue, Doer: doer, ActionType: actionType,
 			Content: "test body", Comment: comment}, tos, fromMention, "TestTemplateServices")
 
-		subject := msg.GetHeader("Subject")
+		subject := msg.ToMessage().GetHeader("Subject")
 		msgbuf := new(bytes.Buffer)
-		_, _ = msg.WriteTo(msgbuf)
+		_, _ = msg.ToMessage().WriteTo(msgbuf)
 		wholemsg := msgbuf.String()
 
 		assert.Equal(t, []string{expSubject}, subject)
diff --git a/services/mailer/mailer.go b/services/mailer/mailer.go
index 2e4aa8d71b..afcc7a7278 100644
--- a/services/mailer/mailer.go
+++ b/services/mailer/mailer.go
@@ -18,7 +18,9 @@ import (
 	"time"
 
 	"code.gitea.io/gitea/modules/base"
+	"code.gitea.io/gitea/modules/graceful"
 	"code.gitea.io/gitea/modules/log"
+	"code.gitea.io/gitea/modules/queue"
 	"code.gitea.io/gitea/modules/setting"
 
 	"github.com/jaytaylor/html2text"
@@ -27,38 +29,63 @@ import (
 
 // Message mail body and log info
 type Message struct {
-	Info string // Message information for log purpose.
-	*gomail.Message
+	Info            string // Message information for log purpose.
+	FromAddress     string
+	FromDisplayName string
+	To              []string
+	Subject         string
+	Date            time.Time
+	Body            string
+	Headers         map[string][]string
 }
 
-// NewMessageFrom creates new mail message object with custom From header.
-func NewMessageFrom(to []string, fromDisplayName, fromAddress, subject, body string) *Message {
-	log.Trace("NewMessageFrom (body):\n%s", body)
-
+// ToMessage converts a Message to gomail.Message
+func (m *Message) ToMessage() *gomail.Message {
 	msg := gomail.NewMessage()
-	msg.SetAddressHeader("From", fromAddress, fromDisplayName)
-	msg.SetHeader("To", to...)
+	msg.SetAddressHeader("From", m.FromAddress, m.FromDisplayName)
+	msg.SetHeader("To", m.To...)
+	for header := range m.Headers {
+		msg.SetHeader(header, m.Headers[header]...)
+	}
+
 	if len(setting.MailService.SubjectPrefix) > 0 {
-		msg.SetHeader("Subject", setting.MailService.SubjectPrefix+" "+subject)
+		msg.SetHeader("Subject", setting.MailService.SubjectPrefix+" "+m.Subject)
 	} else {
-		msg.SetHeader("Subject", subject)
+		msg.SetHeader("Subject", m.Subject)
 	}
-	msg.SetDateHeader("Date", time.Now())
+	msg.SetDateHeader("Date", m.Date)
 	msg.SetHeader("X-Auto-Response-Suppress", "All")
 
-	plainBody, err := html2text.FromString(body)
+	plainBody, err := html2text.FromString(m.Body)
 	if err != nil || setting.MailService.SendAsPlainText {
-		if strings.Contains(base.TruncateString(body, 100), "<html>") {
+		if strings.Contains(base.TruncateString(m.Body, 100), "<html>") {
 			log.Warn("Mail contains HTML but configured to send as plain text.")
 		}
 		msg.SetBody("text/plain", plainBody)
 	} else {
 		msg.SetBody("text/plain", plainBody)
-		msg.AddAlternative("text/html", body)
+		msg.AddAlternative("text/html", m.Body)
 	}
+	return msg
+}
+
+// SetHeader adds additional headers to a message
+func (m *Message) SetHeader(field string, value ...string) {
+	m.Headers[field] = value
+}
+
+// NewMessageFrom creates new mail message object with custom From header.
+func NewMessageFrom(to []string, fromDisplayName, fromAddress, subject, body string) *Message {
+	log.Trace("NewMessageFrom (body):\n%s", body)
 
 	return &Message{
-		Message: msg,
+		FromAddress:     fromAddress,
+		FromDisplayName: fromDisplayName,
+		To:              to,
+		Subject:         subject,
+		Date:            time.Now(),
+		Body:            body,
+		Headers:         map[string][]string{},
 	}
 }
 
@@ -257,18 +284,7 @@ func (s *dummySender) Send(from string, to []string, msg io.WriterTo) error {
 	return nil
 }
 
-func processMailQueue() {
-	for msg := range mailQueue {
-		log.Trace("New e-mail sending request %s: %s", msg.GetHeader("To"), msg.Info)
-		if err := gomail.Send(Sender, msg.Message); err != nil {
-			log.Error("Failed to send emails %s: %s - %v", msg.GetHeader("To"), msg.Info, err)
-		} else {
-			log.Trace("E-mails sent %s: %s", msg.GetHeader("To"), msg.Info)
-		}
-	}
-}
-
-var mailQueue chan *Message
+var mailQueue queue.Queue
 
 // Sender sender for sending mail synchronously
 var Sender gomail.Sender
@@ -291,14 +307,26 @@ func NewContext() {
 		Sender = &dummySender{}
 	}
 
-	mailQueue = make(chan *Message, setting.MailService.QueueLength)
-	go processMailQueue()
+	mailQueue = queue.CreateQueue("mail", func(data ...queue.Data) {
+		for _, datum := range data {
+			msg := datum.(*Message)
+			gomailMsg := msg.ToMessage()
+			log.Trace("New e-mail sending request %s: %s", gomailMsg.GetHeader("To"), msg.Info)
+			if err := gomail.Send(Sender, gomailMsg); err != nil {
+				log.Error("Failed to send emails %s: %s - %v", gomailMsg.GetHeader("To"), msg.Info, err)
+			} else {
+				log.Trace("E-mails sent %s: %s", gomailMsg.GetHeader("To"), msg.Info)
+			}
+		}
+	}, &Message{})
+
+	go graceful.GetManager().RunWithShutdownFns(mailQueue.Run)
 }
 
 // SendAsync send mail asynchronously
 func SendAsync(msg *Message) {
 	go func() {
-		mailQueue <- msg
+		_ = mailQueue.Push(msg)
 	}()
 }
 
@@ -306,7 +334,7 @@ func SendAsync(msg *Message) {
 func SendAsyncs(msgs []*Message) {
 	go func() {
 		for _, msg := range msgs {
-			mailQueue <- msg
+			_ = mailQueue.Push(msg)
 		}
 	}()
 }