Merge "Support project level plugin configuration"

Documentation/dev-plugins.txt

@@ -366,6 +366,45 @@ plugin to parse the `gerrit.config` file on its own:
                        .getString("language", "English");
 ----
 
+[[project-specific-configuration]]
+Project Specific Configuration
+------------------------------
+
+In Gerrit, project specific configuration is stored in the project's
+`project.config` file on the `refs/meta/config` branch.  If a plugin
+needs configuration on project level (e.g. to enable its functionality
+only for certain projects), this configuration should be stored in a
+`plugin` subsection in the project's `project.config` file.
+
+To avoid conflicts with other plugins, it is recommended that plugins
+only use the `plugin` subsection with their own name. For example the
+`helloworld` plugin should store its configuration in the
+`plugin.helloworld` subsection:
+
+----
+  [plugin "helloworld"]
+    enabled = true
+----
+
+Via the `com.google.gerrit.server.config.PluginConfigFactory` class a
+plugin can easily access its project specific configuration and there
+is no need for a plugin to parse the `project.config` file on its own:
+
+[source,java]
+----
+  @Inject
+  private com.google.gerrit.server.config.PluginConfigFactory cfg;
+
+  ...
+
+  boolean enabled = cfg.get(project, "helloworld")
+                       .getBoolean("enabled", false);
+----
+
+Project owners can edit the project configuration by fetching the
+`refs/meta/config` branch, editing the `project.config` file and
+pushing the commit back.
+
 [[capabilities]]
 Plugin Owned Capabilities
 -------------------------

gerrit-server/src/main/java/com/google/gerrit/server/config/PluginConfigFactory.java

@@ -14,6 +14,10 @@
 
 package com.google.gerrit.server.config;
 
+import com.google.gerrit.reviewdb.client.Project;
+import com.google.gerrit.server.project.NoSuchProjectException;
+import com.google.gerrit.server.project.ProjectCache;
+import com.google.gerrit.server.project.ProjectState;
 import com.google.inject.Inject;
 import com.google.inject.Singleton;
 
@@ -22,13 +26,24 @@ import org.eclipse.jgit.lib.Config;
 @Singleton
 public class PluginConfigFactory {
   private final Config cfg;
+  private final ProjectCache projectCache;
 
   @Inject
-  PluginConfigFactory(@GerritServerConfig Config cfg) {
+  PluginConfigFactory(@GerritServerConfig Config cfg, ProjectCache projectCache) {
     this.cfg = cfg;
+    this.projectCache = projectCache;
   }
 
   public PluginConfig get(String pluginName) {
     return new PluginConfig(pluginName, cfg);
   }
+
+  public PluginConfig get(Project.NameKey projectName, String pluginName)
+      throws NoSuchProjectException {
+    ProjectState projectState = projectCache.get(projectName);
+    if (projectState == null) {
+      throw new NoSuchProjectException(projectName);
+    }
+    return projectState.getConfig().getPluginConfig(pluginName);
+  }
 }

gerrit-server/src/main/java/com/google/gerrit/server/git/ProjectConfig.java

@@ -46,6 +46,7 @@ import com.google.gerrit.reviewdb.client.Project.State;
 import com.google.gerrit.reviewdb.client.Project.SubmitType;
 import com.google.gerrit.server.account.GroupBackend;
 import com.google.gerrit.server.config.ConfigUtil;
+import com.google.gerrit.server.config.PluginConfig;
 import com.google.gerrit.server.mail.Address;
 import com.google.gerrit.server.project.CommentLinkInfo;
 
@@ -67,6 +68,7 @@ import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
+import java.util.Map.Entry;
 import java.util.Set;
 import java.util.regex.Pattern;
 import java.util.regex.PatternSyntaxException;
@@ -132,6 +134,8 @@ public class ProjectConfig extends VersionedMetaData {
   private static final Set<String> LABEL_FUNCTIONS = ImmutableSet.of(
       "MaxWithBlock", "AnyWithBlock", "MaxNoBlock", "NoBlock", "NoOp");
 
+  private static final String PLUGIN = "plugin";
+
   private static final SubmitType defaultSubmitAction =
       SubmitType.MERGE_IF_NECESSARY;
   private static final State defaultStateValue =
@@ -149,6 +153,7 @@ public class ProjectConfig extends VersionedMetaData {
   private List<ValidationError> validationErrors;
   private ObjectId rulesId;
   private long maxObjectSizeLimit;
+  private Map<String, Config> pluginConfigs;
 
   public static ProjectConfig read(MetaDataUpdate update) throws IOException,
       ConfigInvalidException {
@@ -399,6 +404,7 @@ public class ProjectConfig extends VersionedMetaData {
     loadNotifySections(rc, groupsByName);
     loadLabelSections(rc);
     loadCommentLinkSections(rc);
+    loadPluginSections(rc);
 
     maxObjectSizeLimit = rc.getLong(RECEIVE, null, KEY_MAX_OBJECT_SIZE_LIMIT, 0);
   }
@@ -683,6 +689,27 @@ public class ProjectConfig extends VersionedMetaData {
     commentLinkSections = ImmutableList.copyOf(commentLinkSections);
   }
 
+  private void loadPluginSections(Config rc) {
+    pluginConfigs = Maps.newHashMap();
+    for (String plugin : rc.getSubsections(PLUGIN)) {
+      Config pluginConfig = new Config();
+      pluginConfigs.put(plugin, pluginConfig);
+      for (String name : rc.getNames(PLUGIN, plugin)) {
+        pluginConfig.setStringList(PLUGIN, plugin, name,
+            Arrays.asList(rc.getStringList(PLUGIN, plugin, name)));
+      }
+    }
+  }
+
+  public PluginConfig getPluginConfig(String pluginName) {
+    Config pluginConfig = pluginConfigs.get(pluginName);
+    if (pluginConfig == null) {
+      pluginConfig = new Config();
+      pluginConfigs.put(pluginName, pluginConfig);
+    }
+    return new PluginConfig(pluginName, pluginConfig);
+  }
+
   private Map<String, GroupReference> readGroupList() throws IOException {
     groupsByUUID = new HashMap<AccountGroup.UUID, GroupReference>();
     Map<String, GroupReference> groupsByName =
@@ -748,6 +775,7 @@ public class ProjectConfig extends VersionedMetaData {
     saveNotifySections(rc, keepGroups);
     groupsByUUID.keySet().retainAll(keepGroups);
     saveLabelSections(rc);
+    savePluginSections(rc);
 
     saveConfig(PROJECT_CONFIG, rc);
     saveGroupList();
@@ -997,6 +1025,22 @@ public class ProjectConfig extends VersionedMetaData {
     }
   }
 
+  private void savePluginSections(Config rc) {
+    List<String> existing = Lists.newArrayList(rc.getSubsections(PLUGIN));
+    for (String name : existing) {
+      rc.unsetSection(PLUGIN, name);
+    }
+
+    for (Entry<String, Config> e : pluginConfigs.entrySet()) {
+      String plugin = e.getKey();
+      Config pluginConfig = e.getValue();
+      for (String name : pluginConfig.getNames(PLUGIN, plugin)) {
+        rc.setStringList(PLUGIN, plugin, name,
+            Arrays.asList(pluginConfig.getStringList(PLUGIN, plugin, name)));
+      }
+    }
+  }
+
   private void saveGroupList() throws IOException {
     if (groupsByUUID.isEmpty()) {
       saveFile(GROUP_LIST, null);