Implement mirror executor (issue-5)

The mirror executor will fetch ref updates for repository mirrors.  This
feature is disabled by default and can be enabled by setting
git.enableMirroring=true.  The period between update checks is
configurable, but it is global.  An individual rpeository may not set
it's own update schedule.

Requirements:
1. you must manually clone the repository using native git
   git clone --mirror git://somewhere.com/myrepo.git
2. the "origin" remote must be the mirror source
3. the "origin" repository must be accessible without authentication OR
   the credentials must be embedded in the origin url (not recommended)

Notes:
1. "origin" SSH urls are untested and not likely to work
2. mirrors cloned while Gitblit is running are likely to require
   clearing the gitblit cache (link on the repositories page of an
   administrator account)
3. Gitblit will automatically repair any invalid fetch refspecs with a
   "//" sequence.

Change-Id: I4bbe3fb2df106366ae4c2313596d0fab0dfcac46

build.xml

@@ -451,6 +451,7 @@
 			<resource file="${project.resources.dir}/commit_merge_16x16.png" />
 			<resource file="${project.resources.dir}/commit_divide_16x16.png" />
 			<resource file="${project.resources.dir}/star_16x16.png" />
+			<resource file="${project.resources.dir}/mirror_16x16.png" />
 			<resource file="${project.resources.dir}/blank.png" />
 			<resource file="${project.src.dir}/log4j.properties" />
 			<resource>

releases.moxie

@@ -16,6 +16,7 @@ r20: {
 	- Fix error on generating activity page when there is no activity
 	- Fix raw page content type of binaries when running behind a reverse proxy
     changes:
+	- Gitblit now rejects pushes to mirror repositories (issue-5)
 	- Personal repository prefix (~) is now configurable (issue-265)
 	- Reversed line links in blob view (issue-309)
 	- Dashboard and Activity pages now obey the web.generateActivityGraph setting (issue-310)
@@ -24,11 +25,12 @@ r20: {
 	- Change the WAR baseFolder context parameter to a JNDI env-entry to improve enterprise deployments
 	- Removed internal Gitblit ref exclusions in the upload pack
 	- Removed "show readme" setting in favor of automatic detection
-	- Support plain text "readme" files
+	- Support plain text, markdown, confluence, mediawiki, textile, tracwiki, or twiki "readme" files
 	- Determine best commit id (e.g. "master") for the tree and docs pages and use that in links
-	- By default GO will now bind to all interfaces for both http and https connectors.  This simplifies setup for first-time users.
+	- By default GO will now bind to all interfaces for both http and https connectors.  This simplifies setup for first-time users.	
 	- Removed docs indicator on the repositories page
     additions:
+	- Added an optional MirrorExecutor which will periodically fetch ref updates from source repositories for mirrors (issue-5).  Repositories must be manually cloned using native git and "--mirror".
 	- Added branch graph image servlet based on EGit's branch graph renderer (issue-194)
 	- Added option to render Markdown commit messages (issue-203)
 	- Added setting to control creating a repository as --shared on Unix servers (issue-263)
@@ -47,7 +49,9 @@ r20: {
     settings:
     - { name: 'git.createRepositoriesShared', defaultValue: 'false' }
     - { name: 'git.allowAnonymousPushes', defaultValue: 'false' }
+	- { name: 'git.enableMirroring', defaultValue: 'false' }
 	- { name: 'git.defaultAccessRestriction', defaultValue: 'PUSH' }
+	- { name: 'git.mirrorPeriod', defaultValue: '30 mins' }
 	- { name: 'web.commitMessageRenderer', defaultValue: 'plain' }
 	- { name: 'web.showBranchGraph', defaultValue: 'true' }
 	- { name: 'server.redirectToHttpsPort', defaultValue: 'true' }

src/main/distrib/data/gitblit.properties

@@ -276,6 +276,34 @@ git.defaultGarbageCollectionThreshold = 500k
 # SINCE 1.2.0
 git.defaultGarbageCollectionPeriod = 7
 
+# Gitblit can automatically fetch ref updates for a properly configured mirror
+# repository.
+#
+# Requirements:
+# 1. you must manually clone the repository using native git
+#    git clone --mirror git://somewhere.com/myrepo.git
+# 2. the "origin" remote must be the mirror source
+# 3. the "origin" repository must be accessible without authentication OR the
+#    credentials must be embedded in the origin url (not recommended)
+#
+# Notes:
+# 1. "origin" SSH urls are untested and not likely to work
+# 2. mirrors cloned while Gitblit is running are likely to require clearing the
+#    gitblit cache (link on the repositories page of an administrator account)
+# 3. Gitblit will automatically repair any invalid fetch refspecs with a "//"
+#    sequence.
+#
+# SINCE 1.4.0
+# RESTART REQUIRED
+git.enableMirroring = false
+
+# Specify the period between update checks for mirrored repositories.
+# The shortest period you may specify between mirror update checks is 5 mins.
+#
+# SINCE 1.4.0
+# RESTART REQUIRED
+git.mirrorPeriod = 30 mins
+
 # Number of bytes of a pack file to load into memory in a single read operation.
 # This is the "page size" of the JGit buffer cache, used for all pack access
 # operations. All disk IO occurs as single window reads. Setting this too large

src/main/java/com/gitblit/GitBlit.java

@@ -164,7 +164,7 @@ public class GitBlit implements ServletContextListener {
 
 	private final Logger logger = LoggerFactory.getLogger(GitBlit.class);
 
-	private final ScheduledExecutorService scheduledExecutor = Executors.newScheduledThreadPool(5);
+	private final ScheduledExecutorService scheduledExecutor = Executors.newScheduledThreadPool(10);
 
 	private final List<FederationModel> federationRegistrations = Collections
 			.synchronizedList(new ArrayList<FederationModel>());
@@ -207,6 +207,8 @@ public class GitBlit implements ServletContextListener {
 
 	private GCExecutor gcExecutor;
 
+	private MirrorExecutor mirrorExecutor;
+
 	private TimeZone timezone;
 
 	private FileBasedConfig projectConfigs;
@@ -2035,6 +2037,7 @@ public class GitBlit implements ServletContextListener {
 			model.origin = config.getString("remote", "origin", "url");
 			if (model.origin != null) {
 				model.origin = model.origin.replace('\\', '/');
+				model.isMirror = config.getBoolean("remote", "origin", "mirror", false);
 			}
 			model.preReceiveScripts = new ArrayList<String>(Arrays.asList(config.getStringList(
 					Constants.CONFIG_GITBLIT, null, "preReceiveScript")));
@@ -3505,6 +3508,7 @@ public class GitBlit implements ServletContextListener {
 		mailExecutor = new MailExecutor(settings);
 		luceneExecutor = new LuceneExecutor(settings, repositoriesFolder);
 		gcExecutor = new GCExecutor(settings);
+		mirrorExecutor = new MirrorExecutor(settings);
 
 		// initialize utilities
 		String prefix = settings.getString(Keys.git.userRepositoryPrefix, "~");
@@ -3544,6 +3548,7 @@ public class GitBlit implements ServletContextListener {
 		configureMailExecutor();
 		configureLuceneIndexing();
 		configureGarbageCollector();
+		configureMirrorExecutor();
 		if (startFederation) {
 			configureFederation();
 		}
@@ -3595,6 +3600,19 @@ public class GitBlit implements ServletContextListener {
 		}
 	}
 
+	protected void configureMirrorExecutor() {
+		if (mirrorExecutor.isReady()) {
+			int mins = TimeUtils.convertFrequencyToMinutes(settings.getString(Keys.git.mirrorPeriod, "30 mins"));
+			if (mins < 5) {
+				mins = 5;
+			}
+			int delay = 1;
+			scheduledExecutor.scheduleAtFixedRate(mirrorExecutor, delay, mins,  TimeUnit.MINUTES);
+			logger.info("Mirror executor is scheduled to fetch updates every {} minutes.", mins);
+			logger.info("Next scheduled mirror fetch is in {} minutes", delay);
+		}
+	}
+
 	protected void configureJGit() {
 		// Configure JGit
 		WindowCacheConfig cfg = new WindowCacheConfig();
@@ -3864,6 +3882,7 @@ public class GitBlit implements ServletContextListener {
 		scheduledExecutor.shutdownNow();
 		luceneExecutor.close();
 		gcExecutor.close();
+		mirrorExecutor.close();
 		if (fanoutService != null) {
 			fanoutService.stop();
 		}

src/main/java/com/gitblit/MirrorExecutor.java

@@ -0,0 +1,169 @@
+/*
+ * Copyright 2013 gitblit.com.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.gitblit;
+
+import java.text.MessageFormat;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+import java.util.concurrent.atomic.AtomicBoolean;
+
+import org.eclipse.jgit.api.Git;
+import org.eclipse.jgit.lib.RefUpdate.Result;
+import org.eclipse.jgit.lib.Repository;
+import org.eclipse.jgit.lib.StoredConfig;
+import org.eclipse.jgit.transport.FetchResult;
+import org.eclipse.jgit.transport.RemoteConfig;
+import org.eclipse.jgit.transport.TrackingRefUpdate;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import com.gitblit.models.RepositoryModel;
+import com.gitblit.models.UserModel;
+import com.gitblit.utils.JGitUtils;
+
+/**
+ * The Mirror executor handles periodic fetching of mirrored repositories.
+ *
+ * @author James Moger
+ *
+ */
+public class MirrorExecutor implements Runnable {
+
+	private final Logger logger = LoggerFactory.getLogger(MirrorExecutor.class);
+
+	private final Set<String> repairAttempted = Collections.synchronizedSet(new HashSet<String>());
+
+	private final IStoredSettings settings;
+
+	private AtomicBoolean running = new AtomicBoolean(false);
+
+	private AtomicBoolean forceClose = new AtomicBoolean(false);
+
+	private final UserModel gitblitUser;
+
+	public MirrorExecutor(IStoredSettings settings) {
+		this.settings = settings;
+		this.gitblitUser = new UserModel("gitblit");
+		this.gitblitUser.displayName = "Gitblit";
+	}
+
+	public boolean isReady() {
+		return settings.getBoolean(Keys.git.enableMirroring, false);
+	}
+
+	public boolean isRunning() {
+		return running.get();
+	}
+
+	public void close() {
+		forceClose.set(true);
+	}
+
+	@Override
+	public void run() {
+		if (!isReady()) {
+			return;
+		}
+
+		running.set(true);
+
+		for (String repositoryName : GitBlit.self().getRepositoryList()) {
+			if (forceClose.get()) {
+				break;
+			}
+			if (GitBlit.self().isCollectingGarbage(repositoryName)) {
+				logger.debug("mirror is skipping {} garbagecollection", repositoryName);
+				continue;
+			}
+			RepositoryModel model = null;
+			Repository repository = null;
+			try {
+				model = GitBlit.self().getRepositoryModel(repositoryName);
+				if (!model.isMirror && !model.isBare) {
+					// repository must be a valid bare git mirror
+					logger.debug("mirror is skipping {} !mirror !bare", repositoryName);
+					continue;
+				}
+
+				repository = GitBlit.self().getRepository(repositoryName);
+				if (repository == null) {
+					logger.warn(MessageFormat.format("MirrorExecutor is missing repository {0}?!?", repositoryName));
+					continue;
+				}
+
+				// automatically repair (some) invalid fetch ref specs
+				if (!repairAttempted.contains(repositoryName)) {
+					repairAttempted.add(repositoryName);
+					JGitUtils.repairFetchSpecs(repository);
+				}
+
+				// find the first mirror remote - there should only be one
+				StoredConfig rc = repository.getConfig();
+				RemoteConfig mirror = null;
+				List<RemoteConfig> configs = RemoteConfig.getAllRemoteConfigs(rc);
+				for (RemoteConfig config : configs) {
+					if (config.isMirror()) {
+						mirror = config;
+						break;
+					}
+				}
+
+				if (mirror == null) {
+					// repository does not have a mirror remote
+					logger.debug("mirror is skipping {} no mirror remote found", repositoryName);
+					continue;
+				}
+
+				logger.debug("checking {} remote {} for ref updates", repositoryName, mirror.getName());
+				final boolean testing = false;
+				Git git = new Git(repository);
+				FetchResult result = git.fetch().setRemote(mirror.getName()).setDryRun(testing).call();
+				Collection<TrackingRefUpdate> refUpdates = result.getTrackingRefUpdates();
+				if (refUpdates.size() > 0) {
+					for (TrackingRefUpdate ru : refUpdates) {
+						StringBuilder sb = new StringBuilder();
+						sb.append("updated mirror ");
+						sb.append(repositoryName);
+						sb.append(" ");
+						sb.append(ru.getRemoteName());
+						sb.append(" -> ");
+						sb.append(ru.getLocalName());
+						if (ru.getResult() == Result.FORCED) {
+							sb.append(" (forced)");
+						}
+						sb.append(" ");
+						sb.append(ru.getOldObjectId() == null ? "" : ru.getOldObjectId().abbreviate(7).name());
+						sb.append("..");
+						sb.append(ru.getNewObjectId() == null ? "" : ru.getNewObjectId().abbreviate(7).name());
+						logger.info(sb.toString());
+					}
+				}
+			} catch (Exception e) {
+				logger.error("Error updating mirror " + repositoryName, e);
+			} finally {
+				// cleanup
+				if (repository != null) {
+					repository.close();
+				}
+			}
+		}
+
+		running.set(false);
+	}
+}

src/main/java/com/gitblit/client/IndicatorsRenderer.java

@@ -56,6 +56,8 @@ public class IndicatorsRenderer extends JPanel implements TableCellRenderer, Ser
 
 	private final ImageIcon sparkleshareIcon;
 
+	private final ImageIcon mirrorIcon;
+
 	public IndicatorsRenderer() {
 		super(new FlowLayout(FlowLayout.RIGHT, 1, 0));
 		blankIcon = new ImageIcon(getClass().getResource("/blank.png"));
@@ -67,6 +69,7 @@ public class IndicatorsRenderer extends JPanel implements TableCellRenderer, Ser
 		federatedIcon = new ImageIcon(getClass().getResource("/federated_16x16.png"));
 		forkIcon = new ImageIcon(getClass().getResource("/commit_divide_16x16.png"));
 		sparkleshareIcon = new ImageIcon(getClass().getResource("/star_16x16.png"));
+		mirrorIcon = new ImageIcon(getClass().getResource("/mirror_16x16.png"));
 	}
 
 	@Override
@@ -85,6 +88,11 @@ public class IndicatorsRenderer extends JPanel implements TableCellRenderer, Ser
 				tooltip.append(Translation.get("gb.isSparkleshared")).append("<br/>");
 				add(icon);
 			}
+			if (model.isMirror) {
+				JLabel icon = new JLabel(mirrorIcon);
+				tooltip.append(Translation.get("gb.isMirror")).append("<br/>");
+				add(icon);
+			}
 			if (model.isFork()) {
 				JLabel icon = new JLabel(forkIcon);
 				tooltip.append(Translation.get("gb.isFork")).append("<br/>");

src/main/java/com/gitblit/git/GitblitReceivePack.java

@@ -120,6 +120,14 @@ public class GitblitReceivePack extends ReceivePack implements PreReceiveHook, P
 	@Override
 	public void onPreReceive(ReceivePack rp, Collection<ReceiveCommand> commands) {
 
+		if (repository.isMirror) {
+			// repository is a mirror
+			for (ReceiveCommand cmd : commands) {
+				sendRejection(cmd, "Gitblit does not allow pushes to \"{0}\" because it is a mirror!", repository.name);
+			}
+			return;
+		}
+
 		if (repository.isFrozen) {
 			// repository is frozen/readonly
 			for (ReceiveCommand cmd : commands) {

src/main/java/com/gitblit/models/RepositoryModel.java

@@ -65,6 +65,7 @@ public class RepositoryModel implements Serializable, Comparable<RepositoryModel
 	public boolean skipSummaryMetrics;
 	public String frequency;
 	public boolean isBare;
+	public boolean isMirror;
 	public String origin;
 	public String HEAD;
 	public List<String> availableRefs;

src/main/java/com/gitblit/models/TeamModel.java

@@ -206,7 +206,7 @@ public class TeamModel implements Serializable, Comparable<TeamModel> {
 
 		// determine maximum permission for the repository
 		final AccessPermission maxPermission =
-				(repository.isFrozen || !repository.isBare) ?
+				(repository.isFrozen || !repository.isBare || repository.isMirror) ?
 						AccessPermission.CLONE : AccessPermission.REWIND;
 
 		if (AccessRestrictionType.NONE.equals(repository.accessRestriction)) {

src/main/java/com/gitblit/models/UserModel.java

@@ -292,7 +292,7 @@ public class UserModel implements Principal, Serializable, Comparable<UserModel>
 
 		// determine maximum permission for the repository
 		final AccessPermission maxPermission =
-				(repository.isFrozen || !repository.isBare) ?
+				(repository.isFrozen || !repository.isBare || repository.isMirror) ?
 						AccessPermission.CLONE : AccessPermission.REWIND;
 
 		if (AccessRestrictionType.NONE.equals(repository.accessRestriction)) {

src/main/java/com/gitblit/utils/JGitUtils.java

@@ -2096,4 +2096,54 @@ public class JGitUtils {
 		}
 		return StringUtils.decodeString(content);
 	}
+
+	/**
+	 * Automatic repair of (some) invalid refspecs.  These are the result of a
+	 * bug in JGit cloning where a double forward-slash was injected.  :(
+	 *
+	 * @param repository
+	 * @return true, if the refspecs were repaired
+	 */
+	public static boolean repairFetchSpecs(Repository repository) {
+		StoredConfig rc = repository.getConfig();
+
+		// auto-repair broken fetch ref specs
+		for (String name : rc.getSubsections("remote")) {
+			int invalidSpecs = 0;
+			int repairedSpecs = 0;
+			List<String> specs = new ArrayList<String>();
+			for (String spec : rc.getStringList("remote", name, "fetch")) {
+				try {
+					RefSpec rs = new RefSpec(spec);
+					// valid spec
+					specs.add(spec);
+				} catch (IllegalArgumentException e) {
+					// invalid spec
+					invalidSpecs++;
+					if (spec.contains("//")) {
+						// auto-repair this known spec bug
+						spec = spec.replace("//", "/");
+						specs.add(spec);
+						repairedSpecs++;
+					}
+				}
+			}
+
+			if (invalidSpecs == repairedSpecs && repairedSpecs > 0) {
+				// the fetch specs were automatically repaired
+				rc.setStringList("remote", name, "fetch", specs);
+				try {
+					rc.save();
+					rc.load();
+					LOGGER.debug("repaired {} invalid fetch refspecs for {}", repairedSpecs, repository.getDirectory());
+					return true;
+				} catch (Exception e) {
+					LOGGER.error(null, e);
+				}
+			} else if (invalidSpecs > 0) {
+				LOGGER.error("mirror executor found {} invalid fetch refspecs for {}", invalidSpecs, repository.getDirectory());
+			}
+		}
+		return false;
+	}
 }

src/main/java/com/gitblit/wicket/GitBlitWebApp.properties

@@ -504,4 +504,7 @@ gb.noActivityToday = there has been no activity today
 gb.anonymousUser= anonymous
 gb.commitMessageRenderer = commit message renderer
 gb.diffStat = {0} insertions & {1} deletions
-gb.home = home
+gb.home = home
+gb.isMirror = this repository is a mirror
+gb.mirrorOf = mirror of {0}
+gb.mirrorWarning = this repository is a mirror and can not receive pushes

src/main/java/com/gitblit/wicket/pages/RepositoryPage.html

@@ -62,6 +62,10 @@
 		<wicket:fragment wicket:id="originFragment">
 			<p class="originRepository"><wicket:message key="gb.forkedFrom">[forked from]</wicket:message> <span wicket:id="originRepository">[origin repository]</span></p>
 		</wicket:fragment>
+
+		<wicket:fragment wicket:id="mirrorFragment">
+			<p class="originRepository"><span wicket:id="originRepository">[origin repository]</span></p>
+		</wicket:fragment>
 				
 	</wicket:extend>
 </body>

src/main/java/com/gitblit/wicket/pages/RepositoryPage.java

@@ -260,7 +260,14 @@ public abstract class RepositoryPage extends RootPage {
 		// indicate origin repository
 		RepositoryModel model = getRepositoryModel();
 		if (StringUtils.isEmpty(model.originRepository)) {
-			add(new Label("originRepository").setVisible(false));
+			if (model.isMirror) {
+				Fragment mirrorFrag = new Fragment("originRepository", "mirrorFragment", this);
+				Label lbl = new Label("originRepository", MessageFormat.format(getString("gb.mirrorOf"), "<b>" + model.origin + "</b>"));
+				mirrorFrag.add(lbl.setEscapeModelStrings(false));
+				add(mirrorFrag);
+			} else {
+				add(new Label("originRepository").setVisible(false));
+			}
 		} else {
 			RepositoryModel origin = GitBlit.self().getRepositoryModel(model.originRepository);
 			if (origin == null) {

src/main/java/com/gitblit/wicket/panels/ProjectRepositoryPanel.html

@@ -39,6 +39,7 @@
 				<span wicket:id="repositoryLinks"></span>
 				<div>
 					<img class="inlineIcon" wicket:id="sparkleshareIcon" />
+					<img class="inlineIcon" wicket:id="mirrorIcon" />
 					<img class="inlineIcon" wicket:id="frozenIcon" />
 					<img class="inlineIcon" wicket:id="federatedIcon" />
         						

src/main/java/com/gitblit/wicket/panels/ProjectRepositoryPanel.java

@@ -87,6 +87,12 @@ public class ProjectRepositoryPanel extends BasePanel {
 			add(WicketUtils.newClearPixel("sparkleshareIcon").setVisible(false));
 		}
 
+		if (entry.isMirror) {
+			add(WicketUtils.newImage("mirrorIcon", "mirror_16x16.png", localizer.getString("gb.isMirror", parent)));
+		} else {
+			add(WicketUtils.newClearPixel("mirrorIcon").setVisible(false));
+		}
+
 		if (entry.isFrozen) {
 			add(WicketUtils.newImage("frozenIcon", "cold_16x16.png", localizer.getString("gb.isFrozen", parent)));
 		} else {

src/main/java/com/gitblit/wicket/panels/RepositoriesPanel.html

@@ -89,7 +89,7 @@
         <td class="left" style="padding-left:3px;" ><b><span class="repositorySwatch" wicket:id="repositorySwatch"></span></b> <span style="padding-left:3px;" wicket:id="repositoryName">[repository name]</span></td>
         <td class="hidden-phone"><span class="list" wicket:id="repositoryDescription">[repository description]</span></td>
         <td class="hidden-tablet hidden-phone author"><span wicket:id="repositoryOwner">[repository owner]</span></td>
-        <td class="hidden-phone" style="text-align: right;padding-right:10px;"><img class="inlineIcon" wicket:id="sparkleshareIcon" /><img class="inlineIcon" wicket:id="forkIcon" /><img class="inlineIcon" wicket:id="frozenIcon" /><img class="inlineIcon" wicket:id="federatedIcon" /><img class="inlineIcon" wicket:id="accessRestrictionIcon" /></td>
+        <td class="hidden-phone" style="text-align: right;padding-right:10px;"><img class="inlineIcon" wicket:id="sparkleshareIcon" /><img class="inlineIcon" wicket:id="mirrorIcon" /><img class="inlineIcon" wicket:id="forkIcon" /><img class="inlineIcon" wicket:id="frozenIcon" /><img class="inlineIcon" wicket:id="federatedIcon" /><img class="inlineIcon" wicket:id="accessRestrictionIcon" /></td>
         <td><span wicket:id="repositoryLastChange">[last change]</span></td>
         <td class="hidden-phone" style="text-align: right;padding-right:15px;"><span style="font-size:0.8em;" wicket:id="repositorySize">[repository size]</span></td>
         <td class="rightAlign">

src/main/java/com/gitblit/wicket/panels/RepositoriesPanel.java

@@ -243,6 +243,13 @@ public class RepositoriesPanel extends BasePanel {
 					row.add(WicketUtils.newClearPixel("sparkleshareIcon").setVisible(false));
 				}
 
+				if (entry.isMirror) {
+					row.add(WicketUtils.newImage("mirrorIcon", "mirror_16x16.png",
+							getString("gb.isMirror")));
+				} else {
+					row.add(WicketUtils.newClearPixel("mirrorIcon").setVisible(false));
+				}
+
 				if (entry.isFork()) {
 					row.add(WicketUtils.newImage("forkIcon", "commit_divide_16x16.png",
 							getString("gb.isFork")));

src/site/features.mkd

@@ -19,6 +19,7 @@
 - Optional feature to allow users to create personal repositories
 - Optional feature to fork a repository to a personal repository
 - Optional feature to create a repository on push
+- Optional feature to automatically fetch ref updates for repository mirrors
 - *Experimental* built-in Garbage Collection
 - Ability to federate with one or more other Gitblit instances
 - RSS/JSON RPC interface

src/test/java/com/gitblit/tests/PermissionsTest.java

@@ -2878,4 +2878,22 @@ public class PermissionsTest extends Assert {
 		assertEquals("user has wrong permission!", AccessPermission.CLONE, user.getRepositoryPermission(repo).permission);
 		assertEquals("team has wrong permission!", AccessPermission.CLONE, team.getRepositoryPermission(repo).permission);
 	}
+
+	@Test
+	public void testIsMirror() throws Exception {
+		RepositoryModel repo = new RepositoryModel("somerepo.git", null, null, new Date());
+		repo.authorizationControl = AuthorizationControl.NAMED;
+		repo.accessRestriction = AccessRestrictionType.NONE;
+
+		UserModel user = new UserModel("test");
+		TeamModel team = new TeamModel("team");
+
+		assertEquals("user has wrong permission!", AccessPermission.REWIND, user.getRepositoryPermission(repo).permission);
+		assertEquals("team has wrong permission!", AccessPermission.REWIND, team.getRepositoryPermission(repo).permission);
+
+		// set repo to be a mirror, pushes prohibited
+		repo.isMirror = true;
+		assertEquals("user has wrong permission!", AccessPermission.CLONE, user.getRepositoryPermission(repo).permission);
+		assertEquals("team has wrong permission!", AccessPermission.CLONE, team.getRepositoryPermission(repo).permission);
+	}
 }