| :linkattrs: |
| = Gerrit Code Review - Plugin Development |
| |
| The Gerrit server functionality can be extended by installing plugins. |
| This page describes how plugins for Gerrit can be developed and hosted |
| on gerrit-review.googlesource.com. |
| |
| For PolyGerrit-specific plugin development, consult with |
| link:pg-plugin-dev.html[PolyGerrit Plugin Development] guide. |
| |
| Depending on how tightly the extension code is coupled with the Gerrit |
| server code, there is a distinction between `plugins` and `extensions`. |
| |
| [[plugin]] |
| A `plugin` in Gerrit is tightly coupled code that runs in the same |
| JVM as Gerrit. It has full access to all server internals. Plugins |
| are tightly coupled to a specific major.minor server version and |
| may require source code changes to compile against a different |
| server version. |
| |
| Plugins may require a specific major.minor.patch server version |
| and may need rebuild and revalidation across different |
| patch levels. A different patch level may only add new |
| API interfaces and never change or extend existing ones. |
| |
| [[extension]] |
| An `extension` in Gerrit runs inside of the same JVM as Gerrit |
| in the same way as a plugin, but has limited visibility to the |
| server's internals. The limited visibility reduces the extension's |
| dependencies, enabling it to be compatible across a wider range |
| of server versions. |
| |
| Most of this documentation refers to either type as a plugin. |
| |
| [[getting-started]] |
| == Getting started |
| |
| To get started with the development of a plugin, take a look at |
| the samples in the |
| link:https://gerrit.googlesource.com/plugins/examples[examples plugin project,role=external,window=_blank]. |
| |
| This is a project that demonstrates the various features of the |
| plugin API. It can be taken as an example to develop an own plugin. |
| |
| When starting from this example one should take care to adapt the |
| `Gerrit-ApiVersion` in the `BUILD` to the version of Gerrit for which |
| the plugin is developed. |
| |
| [[API]] |
| == API |
| |
| There are two different API formats offered against which plugins can |
| be developed: |
| |
| gerrit-extension-api.jar:: |
| A stable but thin interface. Suitable for extensions that need |
| to be notified of events, but do not require tight coupling to |
| the internals of Gerrit. Extensions built against this API can |
| expect to be binary compatible across a wide range of server |
| versions. |
| |
| gerrit-plugin-api.jar:: |
| The complete internals of the Gerrit server, permitting a |
| plugin to tightly couple itself and provide additional |
| functionality that is not possible as an extension. Plugins |
| built against this API are expected to break at the source |
| code level between every major.minor Gerrit release. A plugin |
| that compiles against 2.5 will probably need source code level |
| changes to work with 2.6, 2.7, and so on. |
| |
| == Manifest |
| |
| Plugins may provide optional description information with standard |
| manifest fields: |
| |
| ---- |
| Implementation-Title: Example plugin showing examples |
| Implementation-Version: 1.0 |
| Implementation-Vendor: Example, Inc. |
| ---- |
| |
| === ApiType |
| |
| Plugins using the tightly coupled `gerrit-plugin-api.jar` must |
| declare this API dependency in the manifest to gain access to server |
| internals. If no `Gerrit-ApiType` is specified the stable `extension` |
| API will be assumed. This may cause ClassNotFoundExceptions when |
| loading a plugin that needs the plugin API. |
| |
| ---- |
| Gerrit-ApiType: plugin |
| ---- |
| |
| === Explicit Registration |
| |
| Plugins that use explicit Guice registration must name the Guice |
| modules in the manifest. Up to three modules can be named in the |
| manifest. `Gerrit-Module` supplies bindings to the core server; |
| `Gerrit-SshModule` supplies SSH commands to the SSH server (if |
| enabled); `Gerrit-HttpModule` supplies servlets and filters to the HTTP |
| server (if enabled). If no modules are named automatic registration |
| will be performed by scanning all classes in the plugin JAR for |
| `@Listen` and `@Export("")` annotations. |
| |
| ---- |
| Gerrit-Module: tld.example.project.CoreModuleClassName |
| Gerrit-SshModule: tld.example.project.SshModuleClassName |
| Gerrit-HttpModule: tld.example.project.HttpModuleClassName |
| ---- |
| |
| === Batch runtime |
| |
| Gerrit can be run as a server, serving HTTP or SSH requests, or as an |
| offline program. Plugins can contribute Guice modules to this batch |
| runtime by binding `Gerrit-BatchModule` to one of their classes. |
| The Guice injector is bound to less classes, and some Gerrit features |
| will be absent - on purpose. |
| |
| This feature was originally introduced to support plugins during an |
| offline reindexing task. |
| |
| ---- |
| Gerrit-BatchModule: tld.example.project.CoreModuleClassName |
| ---- |
| |
| In this runtime, only the module designated by `Gerrit-BatchModule` is |
| enabled, not `Gerrit-SysModule`. |
| |
| [[plugin_name]] |
| === Plugin Name |
| |
| A plugin can optionally provide its own plugin name. |
| |
| ---- |
| Gerrit-PluginName: replication |
| ---- |
| |
| This is useful for plugins that contribute plugin-owned capabilities that |
| are stored in the `project.config` file. Another use case is to be able to put |
| project specific plugin configuration section in `project.config`. In this |
| case it is advantageous to reserve the plugin name to access the configuration |
| section in the `project.config` file. |
| |
| If `Gerrit-PluginName` is omitted, then the plugin's name is determined from |
| the plugin file name. |
| |
| If a plugin provides its own name, then that plugin cannot be deployed |
| multiple times under different file names on one Gerrit site. |
| |
| For Maven driven plugins, the following line must be included in the pom.xml |
| file: |
| |
| [source,xml] |
| ---- |
| <manifestEntries> |
| <Gerrit-PluginName>name</Gerrit-PluginName> |
| </manifestEntries> |
| ---- |
| |
| For Bazel driven plugins, the following line must be included in the BUILD |
| configuration file: |
| |
| [source,python] |
| ---- |
| manifest_entries = [ |
| 'Gerrit-PluginName: name', |
| ] |
| ---- |
| |
| A plugin can get its own name injected at runtime: |
| |
| [source,java] |
| ---- |
| public class MyClass { |
| |
| private final String pluginName; |
| |
| @Inject |
| public MyClass(@PluginName String pluginName) { |
| this.pluginName = pluginName; |
| } |
| |
| [...] |
| } |
| ---- |
| |
| A plugin can get its canonical web URL injected at runtime: |
| |
| [source,java] |
| ---- |
| public class MyClass { |
| |
| private final String url; |
| |
| @Inject |
| public MyClass(@PluginCanonicalWebUrl String url) { |
| this.url = url; |
| } |
| |
| [...] |
| } |
| ---- |
| |
| The URL is composed of the server's canonical web URL and the plugin's |
| name, i.e. `http://review.example.com:8080/plugin-name`. |
| |
| The canonical web URL may be injected into any .jar plugin regardless of |
| whether or not the plugin provides an HTTP servlet. |
| |
| [[reload_method]] |
| === Reload Method |
| |
| If a plugin holds an exclusive resource that must be released before |
| loading the plugin again (for example listening on a network port or |
| acquiring a file lock) the manifest must declare `Gerrit-ReloadMode` |
| to be `restart`. Otherwise the preferred method of `reload` will |
| be used, as it enables the server to hot-patch an updated plugin |
| with no down time. |
| |
| ---- |
| Gerrit-ReloadMode: restart |
| ---- |
| |
| In either mode ('restart' or 'reload') any plugin or extension can |
| be updated without restarting the Gerrit server. The difference is |
| how Gerrit handles the upgrade: |
| |
| restart:: |
| The old plugin is completely stopped. All registrations of SSH |
| commands and HTTP servlets are removed. All registrations of any |
| extension points are removed. All registered LifecycleListeners |
| have their `stop()` method invoked in reverse order. The new |
| plugin is started, and registrations are made from the new |
| plugin. There is a brief window where neither the old nor the |
| new plugin is connected to the server. This means SSH commands |
| and HTTP servlets will return not found errors, and the plugin |
| will not be notified of events that occurred during the restart. |
| |
| reload:: |
| The new plugin is started. Its LifecycleListeners are permitted |
| to perform their `start()` methods. All SSH and HTTP registrations |
| are atomically swapped out from the old plugin to the new plugin, |
| ensuring the server never returns a not found error. All extension |
| point listeners are atomically swapped out from the old plugin to |
| the new plugin, ensuring no events are missed (however some events |
| may still route to the old plugin if the swap wasn't complete yet). |
| The old plugin is stopped. |
| |
| To reload/restart a plugin the link:cmd-plugin-reload.html[plugin reload] |
| command can be used. |
| |
| [[init_step]] |
| === Init step |
| |
| Plugins can contribute their own "init step" during the Gerrit init |
| wizard. This is useful for guiding the Gerrit administrator through |
| the settings needed by the plugin to work properly. |
| |
| For instance plugins to integrate Jira issues to Gerrit changes may |
| contribute their own "init step" to allow configuring the Jira URL, |
| credentials and possibly verify connectivity to validate them. |
| |
| ---- |
| Gerrit-InitStep: tld.example.project.MyInitStep |
| ---- |
| |
| MyInitStep needs to follow the standard Gerrit InitStep syntax |
| and behavior: writing to the console using the injected ConsoleUI |
| and accessing / changing configuration settings using Section.Factory. |
| |
| In addition to the standard Gerrit init injections, plugins receive |
| the @PluginName String injection containing their own plugin name. |
| |
| During their initialization plugins may get access to the |
| `project.config` file of the `All-Projects` project and they are able |
| to store configuration parameters in it. For this a plugin `InitStep` |
| can get `com.google.gerrit.pgm.init.api.AllProjectsConfig` injected: |
| |
| [source,java] |
| ---- |
| public class MyInitStep implements InitStep { |
| private final String pluginName; |
| private final ConsoleUI ui; |
| private final AllProjectsConfig allProjectsConfig; |
| |
| @Inject |
| public MyInitStep(@PluginName String pluginName, ConsoleUI ui, |
| AllProjectsConfig allProjectsConfig) { |
| this.pluginName = pluginName; |
| this.ui = ui; |
| this.allProjectsConfig = allProjectsConfig; |
| } |
| |
| @Override |
| public void run() throws Exception { |
| } |
| |
| @Override |
| public void postRun() throws Exception { |
| ui.message("\n"); |
| ui.header(pluginName + " Integration"); |
| boolean enabled = ui.yesno(true, "By default enabled for all projects"); |
| Config cfg = allProjectsConfig.load().getConfig(); |
| if (enabled) { |
| cfg.setBoolean("plugin", pluginName, "enabled", enabled); |
| } else { |
| cfg.unset("plugin", pluginName, "enabled"); |
| } |
| allProjectsConfig.save(pluginName, "Initialize " + pluginName + " Integration"); |
| } |
| } |
| ---- |
| |
| Bear in mind that the Plugin's InitStep class will be loaded but |
| the standard Gerrit runtime environment is not available and the plugin's |
| own Guice modules were not initialized. |
| This means the InitStep for a plugin is not executed in the same way that |
| the plugin executes within the server, and may mean a plugin author cannot |
| trivially reuse runtime code during init. |
| |
| For instance a plugin that wants to verify connectivity may need to statically |
| call the constructor of their connection class, passing in values obtained |
| from the Section.Factory rather than from an injected Config object. |
| |
| Plugins' InitSteps are executed during the "Gerrit Plugin init" phase, after |
| the extraction of the plugins embedded in the distribution .war file into |
| `$GERRIT_SITE/plugins` and before the site initialization or upgrade. |
| |
| A plugin's InitStep cannot refer to any Gerrit runtime objects injected at |
| startup. |
| |
| [source,java] |
| ---- |
| public class MyInitStep implements InitStep { |
| private final ConsoleUI ui; |
| private final Section.Factory sections; |
| private final String pluginName; |
| |
| @Inject |
| public GitBlitInitStep(final ConsoleUI ui, Section.Factory sections, @PluginName String pluginName) { |
| this.ui = ui; |
| this.sections = sections; |
| this.pluginName = pluginName; |
| } |
| |
| @Override |
| public void run() throws Exception { |
| ui.header("\nMy plugin"); |
| |
| Section mySection = getSection("myplugin", null); |
| mySection.string("Link name", "linkname", "MyLink"); |
| } |
| |
| @Override |
| public void postRun() throws Exception { |
| } |
| } |
| ---- |
| |
| [[classpath]] |
| == Classpath |
| |
| Each plugin is loaded into its own ClassLoader, isolating plugins |
| from each other. A plugin or extension inherits the Java runtime |
| and the Gerrit API chosen by `Gerrit-ApiType` (extension or plugin) |
| from the hosting server. |
| |
| Plugins are loaded from a single JAR file. If a plugin needs |
| additional libraries, it must include those dependencies within |
| its own JAR. Plugins built using Maven may be able to use the |
| link:http://maven.apache.org/plugins/maven-shade-plugin/[shade plugin,role=external,window=_blank] |
| to package additional dependencies. Relocating (or renaming) classes |
| should not be necessary due to the ClassLoader isolation. |
| |
| [[events]] |
| == Listening to Events |
| |
| Certain operations in Gerrit trigger events. Plugins may receive |
| notifications of these events by implementing the corresponding |
| listeners. |
| |
| * `com.google.gerrit.common.EventListener`: |
| + |
| Allows to listen to events without user visibility restrictions. These |
| are the same link:cmd-stream-events.html#events[events] that are also streamed by |
| the link:cmd-stream-events.html[gerrit stream-events] command. |
| |
| * `com.google.gerrit.common.UserScopedEventListener`: |
| + |
| Allows to listen to events visible to the specified user. These are the |
| same link:cmd-stream-events.html#events[events] that are also streamed |
| by the link:cmd-stream-events.html[gerrit stream-events] command. |
| |
| * `com.google.gerrit.extensions.events.AccountActivationListener`: |
| + |
| User account got activated or deactivated |
| |
| * `com.google.gerrit.extensions.events.LifecycleListener`: |
| + |
| Plugin start and stop |
| |
| * `com.google.gerrit.extensions.events.NewProjectCreatedListener`: |
| + |
| Project creation |
| |
| * `com.google.gerrit.extensions.events.ProjectDeletedListener`: |
| + |
| Project deletion |
| |
| * `com.google.gerrit.extensions.events.HeadUpdatedListener`: |
| + |
| Update of HEAD on a project |
| |
| * `com.google.gerrit.extensions.events.UsageDataPublishedListener`: |
| + |
| Publication of usage data |
| |
| * `com.google.gerrit.extensions.events.GarbageCollectorListener`: |
| + |
| Garbage collection ran on a project |
| |
| * `com.google.gerrit.server.extensions.events.ChangeIndexedListener`: |
| + |
| Update of the change secondary index |
| |
| * `com.google.gerrit.server.extensions.events.AccountIndexedListener`: |
| + |
| Update of the account secondary index |
| |
| * `com.google.gerrit.server.extensions.events.GroupIndexedListener`: |
| + |
| Update of the group secondary index |
| |
| * `com.google.gerrit.server.extensions.events.ProjectIndexedListener`: |
| + |
| Update of the project secondary index |
| |
| * `com.google.gerrit.httpd.WebLoginListener`: |
| + |
| User login or logout interactively on the Web user interface. |
| |
| The event listener is under the Gerrit http package to automatically |
| inherit the javax.servlet.http dependencies and allowing to influence |
| the login or logout flow with additional redirections. |
| |
| [[stream-events]] |
| == Sending Events to the Events Stream |
| |
| Plugins may send events to the events stream where consumers of |
| Gerrit's `stream-events` ssh command will receive them. |
| |
| To send an event, the plugin must invoke one of the `postEvent` |
| methods in the `EventDispatcher` interface, passing an instance of |
| its own custom event class derived from |
| `com.google.gerrit.server.events.Event`. |
| |
| [source,java] |
| ---- |
| import com.google.gerrit.common.EventDispatcher; |
| import com.google.gerrit.exceptions.StorageException; |
| import com.google.gerrit.extensions.registration.DynamicItem; |
| import com.google.inject.Inject; |
| |
| class MyPlugin { |
| private final DynamicItem<EventDispatcher> eventDispatcher; |
| |
| @Inject |
| myPlugin(DynamicItem<EventDispatcher> eventDispatcher) { |
| this.eventDispatcher = eventDispatcher; |
| } |
| |
| private void postEvent(MyPluginEvent event) { |
| try { |
| eventDispatcher.get().postEvent(event); |
| } catch (StorageException e) { |
| // error handling |
| } |
| } |
| } |
| ---- |
| |
| Plugins which define new Events should register them via the |
| `com.google.gerrit.server.events.EventTypes.register()` method. |
| This will make the EventType known to the system. Deserializing |
| events with the |
| `com.google.gerrit.server.events.EventDeserializer` class requires |
| that the event be registered in EventTypes. |
| |
| == Modifying the Stream Event Flow |
| |
| It is possible to modify the stream event flow from plugins by registering |
| an `com.google.gerrit.server.events.EventDispatcher`. A plugin may register |
| a Dispatcher class to replace the internal Dispatcher. EventDispatcher is |
| a DynamicItem, so Gerrit may only have one copy. |
| |
| [[validation]] |
| == Validation Listeners |
| |
| Certain operations in Gerrit can be validated by plugins by |
| implementing the corresponding link:config-validation.html[listeners]. |
| |
| [[change-message-modifier]] |
| == Change Message Modifier |
| |
| `com.google.gerrit.server.git.ChangeMessageModifier`: |
| plugins implementing this can modify commit message of the change being |
| submitted by Rebase Always and Cherry Pick submit strategies as well as |
| change being queried with COMMIT_FOOTERS option. |
| |
| [[merge-super-set-computation]] |
| == Merge Super Set Computation |
| |
| The algorithm to compute the merge super set to detect changes that |
| should be submitted together can be customized by implementing |
| `com.google.gerrit.server.git.MergeSuperSetComputation`. |
| MergeSuperSetComputation is a DynamicItem, so Gerrit may only have one |
| implementation. |
| |
| [[receive-pack]] |
| == Receive Pack Initializers |
| |
| Plugins may provide ReceivePackInitializer instances, which will be |
| invoked by Gerrit just before a ReceivePack instance will be used. |
| Usually, plugins will make use of the setXXX methods on the ReceivePack |
| to set additional properties on it. |
| |
| The interactions with the core Gerrit ReceivePack initialization and |
| between ReceivePackInitializers can be complex. Please read the |
| ReceivePack Javadoc and Gerrit AsyncReceiveCommits implementation |
| carefully. |
| |
| [[post-receive-hook]] |
| == Post Receive-Pack Hooks |
| |
| Plugins may register PostReceiveHook instances in order to get |
| notified when JGit successfully receives a pack. This may be useful |
| for those plugins which would like to monitor changes in Git |
| repositories. |
| |
| [[upload-pack]] |
| == Upload Pack Initializers |
| |
| Plugins may provide UploadPackInitializer instances, which will be |
| invoked by Gerrit just before a UploadPack instance will be used. |
| Usually, plugins will make use of the setXXX methods on the UploadPack |
| to set additional properties on it. |
| |
| The interactions with the core Gerrit UploadPack initialization and |
| between UploadPackInitializers can be complex. Please read the |
| UploadPack Javadoc and Gerrit Upload/UploadFactory implementations |
| carefully. |
| |
| [[pre-upload-hook]] |
| == Pre Upload-Pack Hooks |
| |
| Plugins may register PreUploadHook instances in order to get |
| notified when JGit is about to upload a pack. This may be useful |
| for those plugins which would like to monitor usage in Git |
| repositories. |
| |
| [[post-upload-hook]] |
| == Post Upload-Pack Hooks |
| |
| Plugins may register PostUploadHook instances in order to get notified after |
| JGit is done uploading a pack. |
| |
| [[ssh]] |
| == SSH Commands |
| |
| Plugins may provide commands that can be accessed through the SSH |
| interface (extensions do not have this option). |
| |
| Command implementations must extend the base class SshCommand: |
| |
| [source,java] |
| ---- |
| import com.google.gerrit.sshd.SshCommand; |
| import com.google.gerrit.sshd.CommandMetaData; |
| |
| @CommandMetaData(name="print", description="Print hello command") |
| class PrintHello extends SshCommand { |
| @Override |
| protected void run() { |
| stdout.print("Hello\n"); |
| } |
| } |
| ---- |
| |
| If no Guice modules are declared in the manifest, SSH commands may |
| use auto-registration by providing an `@Export` annotation: |
| |
| [source,java] |
| ---- |
| import com.google.gerrit.extensions.annotations.Export; |
| import com.google.gerrit.sshd.SshCommand; |
| |
| @Export("print") |
| class PrintHello extends SshCommand { |
| @Override |
| protected void run() { |
| stdout.print("Hello\n"); |
| } |
| } |
| ---- |
| |
| If explicit registration is being used, a Guice module must be |
| supplied to register the SSH command and declared in the manifest |
| with the `Gerrit-SshModule` attribute: |
| |
| [source,java] |
| ---- |
| import com.google.gerrit.sshd.PluginCommandModule; |
| |
| class MyCommands extends PluginCommandModule { |
| @Override |
| protected void configureCommands() { |
| command(PrintHello.class); |
| } |
| } |
| ---- |
| |
| For a plugin installed as name `helloworld`, the command implemented |
| by PrintHello class will be available to users as: |
| |
| ---- |
| $ ssh -p 29418 review.example.com helloworld print |
| ---- |
| |
| [[multiple-commands]] |
| === Multiple Commands bound to one implementation |
| |
| Multiple SSH commands can be bound to the same implementation class. For |
| example a Gerrit Shell plugin can bind different shell commands to the same |
| implementation class: |
| |
| [source,java] |
| ---- |
| public class SshShellModule extends PluginCommandModule { |
| @Override |
| protected void configureCommands() { |
| command("ls").to(ShellCommand.class); |
| command("ps").to(ShellCommand.class); |
| [...] |
| } |
| } |
| ---- |
| |
| With the possible implementation: |
| |
| [source,java] |
| ---- |
| public class ShellCommand extends SshCommand { |
| @Override |
| protected void run() throws UnloggedFailure { |
| String cmd = getName().substring(getPluginName().length() + 1); |
| ProcessBuilder proc = new ProcessBuilder(cmd); |
| Process cmd = proc.start(); |
| [...] |
| } |
| } |
| ---- |
| |
| And the call: |
| |
| ---- |
| $ ssh -p 29418 review.example.com shell ls |
| $ ssh -p 29418 review.example.com shell ps |
| ---- |
| |
| [[root-level-commands]] |
| === Root Level Commands |
| |
| Single command plugins are also supported. In this scenario plugin binds |
| SSH command to its own name. `SshModule` must inherit from |
| `SingleCommandPluginModule` class: |
| |
| [source,java] |
| ---- |
| public class SshModule extends SingleCommandPluginModule { |
| @Override |
| protected void configure(LinkedBindingBuilder<Command> b) { |
| b.to(ShellCommand.class); |
| } |
| } |
| ---- |
| |
| If the plugin above is deployed under sh.jar file in `$site/plugins` |
| directory, generic commands can be called without specifying the |
| actual SSH command. Note in the example below, that the called commands |
| `ls` and `ps` was not explicitly bound: |
| |
| ---- |
| $ ssh -p 29418 review.example.com sh ls |
| $ ssh -p 29418 review.example.com sh ps |
| ---- |
| |
| [[search_operators]] |
| == Search Operators |
| |
| Plugins can define new search operators to extend change searching by |
| implementing the `ChangeQueryBuilder.ChangeOperatorFactory` interface |
| and registering it to an operator name in the plugin module's |
| `configure()` method. The search operator name is defined during |
| registration via the DynamicMap annotation mechanism. The plugin |
| name will get appended to the annotated name, with an underscore |
| in between, leading to the final operator name. An example |
| registration looks like this: |
| |
| [source,java] |
| ---- |
| bind(ChangeOperatorFactory.class) |
| .annotatedWith(Exports.named("sample")) |
| .to(SampleOperator.class); |
| ---- |
| |
| If this is registered in the `myplugin` plugin, then the resulting |
| operator will be named `sample_myplugin`. |
| |
| The search operator itself is implemented by ensuring that the |
| `create()` method of the class implementing the |
| `ChangeQueryBuilder.ChangeOperatorFactory` interface returns a |
| `Predicate<ChangeData>`. Here is a sample operator factory |
| definition which creates a `MyPredicate`: |
| |
| [source,java] |
| ---- |
| public class SampleOperator |
| implements ChangeQueryBuilder.ChangeOperatorFactory { |
| public static class MyPredicate extends PostFilterPredicate<ChangeData> { |
| ... |
| } |
| |
| @Override |
| public Predicate<ChangeData> create(ChangeQueryBuilder builder, String value) |
| throws QueryParseException { |
| return new MyPredicate(value); |
| } |
| } |
| ---- |
| |
| [[search_operands]] |
| == Search Operands |
| |
| Plugins can define new search operands to extend change searching. |
| Plugin methods implementing search operands (returning a |
| `Predicate<ChangeData>`), must be defined on a class implementing |
| one of the `ChangeQueryBuilder.ChangeOperandsFactory` interfaces |
| (.e.g., ChangeQueryBuilder.ChangeHasOperandFactory). The specific |
| `ChangeOperandFactory` class must also be bound to the `DynamicSet` from |
| a module's `configure()` method in the plugin. |
| |
| The new operand, when used in a search would appear as: |
| `operatorName:operandName_pluginName` |
| |
| A sample `ChangeHasOperandFactory` class implementing, and registering, a |
| new `has:sample_pluginName` operand is shown below: |
| |
| [source, java] |
| ---- |
| public class SampleHasOperand implements ChangeHasOperandFactory { |
| public static class Module extends AbstractModule { |
| @Override |
| protected void configure() { |
| bind(ChangeHasOperandFactory.class) |
| .annotatedWith(Exports.named("sample") |
| .to(SampleHasOperand.class); |
| } |
| } |
| |
| @Override |
| public Predicate<ChangeData> create(ChangeQueryBuilder builder) |
| throws QueryParseException { |
| return new HasSamplePredicate(); |
| } |
| } |
| ---- |
| |
| [[command_options]] |
| == Command Options |
| |
| Plugins can provide additional options for each of the gerrit ssh and the |
| REST API commands by implementing the DynamicBean interface and registering |
| it to a command class name in the plugin module's `configure()` method. The |
| plugin's name will be prepended to the name of each @Option annotation found |
| on the DynamicBean object provided by the plugin. The example below shows a |
| plugin that adds an option to log a value from the gerrit 'ban-commits' |
| ssh command. |
| |
| [source, java] |
| ---- |
| public class SshModule extends AbstractModule { |
| private static final FluentLogger logger = FluentLogger.forEnclosingClass(); |
| |
| @Override |
| protected void configure() { |
| bind(DynamicOptions.DynamicBean.class) |
| .annotatedWith(Exports.named( |
| com.google.gerrit.sshd.commands.BanCommitCommand.class)) |
| .to(BanOptions.class); |
| } |
| |
| public static class BanOptions implements DynamicOptions.DynamicBean { |
| @Option(name = "--log", aliases = { "-l" }, usage = "Say Hello in the Log") |
| private void parse(String arg) { |
| logger.atSevere().log("Say Hello in the Log %s", arg); |
| } |
| } |
| } |
| ---- |
| |
| Plugins can receive a bean object for each of the gerrit ssh and the REST API |
| commands by implementing BeanParseListener interface and registering it to a |
| command class name in the plugin module's `configure()` method. The below |
| example shows a plugin that always limits the number of projects returned |
| by the ls-projects SSH command. |
| |
| [source, java] |
| ---- |
| protected static class PluginModule extends AbstractModule { |
| @Override |
| public void configure() { |
| bind(DynamicOptions.DynamicBean.class) |
| .annotatedWith(Exports.named(ListProjectsCommand.class)) |
| .to(ListProjectsCommandBeanListener.class); |
| } |
| |
| protected static class ListProjectsCommandBeanListener |
| implements DynamicOptions.BeanParseListener { |
| @Override |
| public void onBeanParseStart(String plugin, Object bean) { |
| ListProjectsCommand command = (ListProjectsCommand) bean; |
| command.impl.setLimit(1); |
| } |
| |
| @Override |
| public void onBeanParseEnd(String plugin, Object bean) {} |
| } |
| } |
| ---- |
| |
| The below example shows a plugin that always limits the number of projects |
| returned by the /projects/ REST API. |
| |
| [source, java] |
| ---- |
| protected static class PluginModule extends AbstractModule { |
| @Override |
| public void configure() { |
| bind(DynamicOptions.DynamicBean.class) |
| .annotatedWith(Exports.named(ListProjects.class)) |
| .to(ListProjectsBeanListener.class); |
| } |
| |
| protected static class ListProjectsBeanListener |
| implements DynamicOptions.BeanParseListener { |
| @Override |
| public void onBeanParseStart(String plugin, Object bean) { |
| ListProjects listProjects = (ListProjects) bean; |
| listProjects.setLimit(1); |
| } |
| |
| @Override |
| public void onBeanParseEnd(String plugin, Object bean) {} |
| } |
| } |
| ---- |
| |
| === Calling Command Options === |
| |
| Within an OptionHandler, during the processing of an option, plugins can |
| provide and call extra parameters on the current command during parsing |
| simulating as if they had been passed from the command line originally. |
| |
| To call additional parameters from within an option handler, instantiate |
| the com.google.gerrit.util.cli.CmdLineParser.Parameters class with the |
| existing parameters, and then call callParameters() with the additional |
| parameters to be parsed. OptionHandlers may optionally pass this class to |
| other methods which may then both parse/consume more parameters and call |
| additional parameters. |
| |
| When calling command options not provided by your plugin, there is always |
| a risk that the options may not exist, perhaps because the options being |
| called are to be provided by another plugin, and said plugin is not |
| currently installed. To protect againt this situation, it is possible to |
| define an option as being dependent on other options using the |
| @RequiresOptions() annotation. If the required options are not all not |
| currently present, then the dependent option will not be available or |
| visible in the help. |
| |
| The example below shows a plugin that adds a "--special" option (perhaps |
| for use with the Query command) that calls (and requires) the |
| "--format json" option. |
| |
| [source, java] |
| ---- |
| public class JsonOutputOptionHandler<T> extends OptionHandler<T> { |
| protected com.google.gerrit.util.cli.CmdLineParser.MyParser myParser; |
| |
| public JsonOutputOptionHandler(CmdLineParser parser, OptionDef option, Setter<? super T> setter) { |
| super(parser, option, setter); |
| myParser = (com.google.gerrit.util.cli.CmdLineParser.MyParser) owner; |
| } |
| |
| @Override |
| public int parseArguments(org.kohsuke.args4j.spi.Parameters params) throws CmdLineException { |
| new Parameters(params, myParser).callParameters("--format", "json"); |
| setter.addValue(true); |
| return 0; // we didn't consume any additional args |
| } |
| |
| @Override |
| public String getDefaultMetaVariable() { |
| ... |
| } |
| } |
| |
| @RequiresOptions("--format") |
| @Option( |
| name = "--special", |
| usage = "ouptut results using json", |
| handler = JsonOutputOptionHandler.class |
| ) |
| boolean json; |
| ---- |
| |
| [[query_attributes]] |
| == Change Attributes |
| |
| Plugins can provide additional attributes to be returned from the Get Change and |
| Query Change APIs by implementing implementing the `ChangeAttributeFactory` |
| interface and adding it to the `DynamicSet` in the plugin module's `configure()` |
| method. The new attribute(s) will be output under a `plugin` attribute in the |
| change output. This can be further controlled by registering a class containing |
| @Option declarations as a `DynamicBean`, annotated with the with HTTP/SSH |
| commands on which the options should be available. |
| |
| The example below shows a plugin that adds two attributes (`exampleName` and |
| `changeValue`), to the change query output, when the query command is provided |
| the `--myplugin-name--all` option. |
| |
| [source, java] |
| ---- |
| public class Module extends AbstractModule { |
| @Override |
| protected void configure() { |
| // Register attribute factory. |
| DynamicSet.bind(binder(), ChangeAttributeFactory.class) |
| .to(AttributeFactory.class); |
| |
| // Register options for GET /changes/X/change and /changes/X/detail. |
| bind(DynamicBean.class) |
| .annotatedWith(Exports.named(GetChange.class)) |
| .to(MyChangeOptions.class); |
| |
| // Register options for GET /changes/?q=... |
| bind(DynamicBean.class) |
| .annotatedWith(Exports.named(QueryChanges.class)) |
| .to(MyChangeOptions.class); |
| |
| // Register options for ssh gerrit query. |
| bind(DynamicBean.class) |
| .annotatedWith(Exports.named(Query.class)) |
| .to(MyChangeOptions.class); |
| } |
| } |
| |
| public class MyChangeOptions implements DynamicBean { |
| @Option(name = "--all", usage = "Include plugin output") |
| public boolean all = false; |
| } |
| |
| public class AttributeFactory implements ChangeAttributeFactory { |
| protected MyChangeOptions options; |
| |
| public class PluginAttribute extends PluginDefinedInfo { |
| public String exampleName; |
| public String changeValue; |
| |
| public PluginAttribute(ChangeData c) { |
| this.exampleName = "Attribute Example"; |
| this.changeValue = Integer.toString(c.getId().get()); |
| } |
| } |
| |
| @Override |
| public PluginDefinedInfo create(ChangeData c, BeanProvider bp, String plugin) { |
| if (options == null) { |
| options = (MyChangeOptions) bp.getDynamicBean(plugin); |
| } |
| if (options.all) { |
| return new PluginAttribute(c); |
| } |
| return null; |
| } |
| } |
| ---- |
| |
| Example: |
| ---- |
| $ ssh -p 29418 localhost gerrit query --myplugin-name--all "change:1" --format json |
| { |
| "url" : "http://localhost:8080/1", |
| "plugins" : [ |
| { |
| "name" : "myplugin-name", |
| "exampleName" : "Attribute Example", |
| "changeValue" : "1" |
| } |
| ], |
| ... |
| } |
| |
| $ curl http://localhost:8080/changes/1?myplugin-name--all |
| { |
| "_number": 1, |
| ... |
| "plugins": [ |
| { |
| "name": "myplugin-name", |
| "example_name": "Attribute Example", |
| "change_value": "1" |
| } |
| ], |
| ... |
| } |
| ---- |
| |
| Implementors of the `ChangeAttributeFactory` interface should check whether |
| they need to contribute to the link:#change-etag-computation[change ETag |
| computation] to prevent callers using ETags from potentially seeing outdated |
| plugin attributes. |
| |
| [[simple-configuration]] |
| == Simple Configuration in `gerrit.config` |
| |
| In Gerrit, global configuration is stored in the `gerrit.config` file. |
| If a plugin needs global configuration, this configuration should be |
| stored in a `plugin` subsection in the `gerrit.config` file. |
| |
| This approach of storing the plugin configuration is only suitable for |
| plugins that have a simple configuration that only consists of |
| key-value pairs. With this approach it is not possible to have |
| subsections in the plugin configuration. Plugins that require a complex |
| configuration need to store their configuration in their |
| link:#configuration[own configuration file] where they can make use of |
| subsections. On the other hand storing the plugin configuration in a |
| 'plugin' subsection in the `gerrit.config` file has the advantage that |
| administrators have all configuration parameters in one file, instead |
| of having one configuration file per plugin. |
| |
| 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"] |
| language = Latin |
| ---- |
| |
| Via the `com.google.gerrit.server.config.PluginConfigFactory` class a |
| plugin can easily access its configuration and there is no need for a |
| plugin to parse the `gerrit.config` file on its own: |
| |
| [source,java] |
| ---- |
| @Inject |
| private com.google.gerrit.server.config.PluginConfigFactory cfg; |
| |
| [...] |
| |
| String language = cfg.getFromGerritConfig("helloworld") |
| .getString("language", "English"); |
| ---- |
| |
| [[configuration]] |
| == Configuration in own config file |
| |
| Plugins can store their configuration in an own configuration file. |
| This makes sense if the plugin configuration is rather complex and |
| requires the usage of subsections. Plugins that have a simple |
| key-value pair configuration can store their configuration in a |
| link:#simple-configuration[`plugin` subsection of the `gerrit.config` |
| file]. |
| |
| The plugin configuration file must be named after the plugin and must |
| be located in the `etc` folder of the review site. For example a |
| configuration file for a `default-reviewer` plugin could look like |
| this: |
| |
| .$site_path/etc/default-reviewer.config |
| ---- |
| [branch "refs/heads/master"] |
| reviewer = Project Owners |
| reviewer = john.doe@example.com |
| [match "file:^.*\.txt"] |
| reviewer = My Info Developers |
| ---- |
| |
| Plugins that have sensitive configuration settings can store those settings in |
| an own secure configuration file. The plugin's secure configuration file must be |
| named after the plugin and must be located in the `etc` folder of the review |
| site. For example a secure configuration file for a `default-reviewer` plugin |
| could look like this: |
| |
| .$site_path/etc/default-reviewer.secure.config |
| ---- |
| [auth] |
| password = secret |
| ---- |
| |
| Via the `com.google.gerrit.server.config.PluginConfigFactory` class a |
| plugin can easily access its configuration: |
| |
| [source,java] |
| ---- |
| @Inject |
| private com.google.gerrit.server.config.PluginConfigFactory cfg; |
| |
| [...] |
| |
| String[] reviewers = cfg.getGlobalPluginConfig("default-reviewer") |
| .getStringList("branch", "refs/heads/master", "reviewer"); |
| String password = cfg.getGlobalPluginConfig("default-reviewer") |
| .getString("auth", null, "password"); |
| ---- |
| |
| |
| [[simple-project-specific-configuration]] |
| == Simple Project Specific Configuration in `project.config` |
| |
| 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. |
| |
| This approach of storing the plugin configuration is only suitable for |
| plugins that have a simple configuration that only consists of |
| key-value pairs. With this approach it is not possible to have |
| subsections in the plugin configuration. Plugins that require a complex |
| configuration need to store their configuration in their |
| link:#project-specific-configuration[own configuration file] where they |
| can make use of subsections. On the other hand storing the plugin |
| configuration in a 'plugin' subsection in the `project.config` file has |
| the advantage that project owners have all configuration parameters in |
| one file, instead of having one configuration file per plugin. |
| |
| 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.getFromProjectConfig(project, "helloworld") |
| .getBoolean("enabled", false); |
| ---- |
| |
| It is also possible to get missing configuration parameters inherited |
| from the parent projects: |
| |
| [source,java] |
| ---- |
| @Inject |
| private com.google.gerrit.server.config.PluginConfigFactory cfg; |
| |
| [...] |
| |
| boolean enabled = cfg.getFromProjectConfigWithInheritance(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. |
| |
| Plugin configuration values that are stored in the `project.config` |
| file can be exposed in the ProjectInfoScreen to allow project owners |
| to see and edit them from the UI. |
| |
| For this an instance of `ProjectConfigEntry` needs to be bound for each |
| parameter. The export name must be a valid Git variable name. The |
| variable name is case-insensitive, allows only alphanumeric characters |
| and '-', and must start with an alphabetic character. |
| |
| The example below shows how the parameters `plugin.helloworld.enabled` |
| and `plugin.helloworld.language` are bound to be editable from the |
| Web UI. For the parameter `plugin.helloworld.enabled` "Enable Greeting" |
| is provided as display name and the default value is set to `true`. |
| For the parameter `plugin.helloworld.language` "Preferred Language" |
| is provided as display name and "en" is set as default value. |
| |
| [source,java] |
| ---- |
| class Module extends AbstractModule { |
| @Override |
| protected void configure() { |
| bind(ProjectConfigEntry.class) |
| .annotatedWith(Exports.named("enabled")) |
| .toInstance(new ProjectConfigEntry("Enable Greeting", true)); |
| bind(ProjectConfigEntry.class) |
| .annotatedWith(Exports.named("language")) |
| .toInstance(new ProjectConfigEntry("Preferred Language", "en")); |
| } |
| } |
| ---- |
| |
| By overwriting the `onUpdate` method of `ProjectConfigEntry` plugins |
| can be notified when this configuration parameter is updated on a |
| project. |
| |
| [[configuring-groups]] |
| === Referencing groups in `project.config` |
| |
| Plugins can refer to groups so that when they are renamed, the project |
| config will also be updated in this section. The proper format to use is |
| the same as for any other group reference in the `project.config`, as shown below. |
| |
| ---- |
| group group_name |
| ---- |
| |
| The file `groups` must also contains the mapping of the group name and its UUID, |
| refer to link:config-project-config.html#file-groups[file groups] |
| |
| [[project-specific-configuration]] |
| == Project Specific Configuration in own config file |
| |
| Plugins can store their project specific configuration in an own |
| configuration file in the projects `refs/meta/config` branch. |
| This makes sense if the plugins project specific configuration is |
| rather complex and requires the usage of subsections. Plugins that |
| have a simple key-value pair configuration can store their project |
| specific configuration in a link:#simple-project-specific-configuration[ |
| `plugin` subsection of the `project.config` file]. |
| |
| The plugin configuration file in the `refs/meta/config` branch must be |
| named after the plugin. For example a configuration file for a |
| `default-reviewer` plugin could look like this: |
| |
| .default-reviewer.config |
| ---- |
| [branch "refs/heads/master"] |
| reviewer = Project Owners |
| reviewer = john.doe@example.com |
| [match "file:^.*\.txt"] |
| reviewer = My Info Developers |
| ---- |
| |
| Via the `com.google.gerrit.server.config.PluginConfigFactory` class a |
| plugin can easily access its project specific configuration: |
| |
| [source,java] |
| ---- |
| @Inject |
| private com.google.gerrit.server.config.PluginConfigFactory cfg; |
| |
| [...] |
| |
| String[] reviewers = cfg.getProjectPluginConfig(project, "default-reviewer") |
| .getStringList("branch", "refs/heads/master", "reviewer"); |
| ---- |
| |
| It is also possible to get missing configuration parameters inherited |
| from the parent projects: |
| |
| [source,java] |
| ---- |
| @Inject |
| private com.google.gerrit.server.config.PluginConfigFactory cfg; |
| |
| [...] |
| |
| String[] reviewers = cfg.getProjectPluginConfigWithInheritance(project, "default-reviewer") |
| .getStringList("branch", "refs/heads/master", "reviewer"); |
| ---- |
| |
| Project owners can edit the project configuration by fetching the |
| `refs/meta/config` branch, editing the `<plugin-name>.config` file and |
| pushing the commit back. |
| |
| == React on changes in project configuration |
| |
| If a plugin wants to react on changes in the project configuration, it |
| can implement a `GitReferenceUpdatedListener` and filter on events for |
| the `refs/meta/config` branch: |
| |
| [source,java] |
| ---- |
| public class MyListener implements GitReferenceUpdatedListener { |
| |
| private final MetaDataUpdate.Server metaDataUpdateFactory; |
| |
| @Inject |
| MyListener(MetaDataUpdate.Server metaDataUpdateFactory) { |
| this.metaDataUpdateFactory = metaDataUpdateFactory; |
| } |
| |
| @Override |
| public void onGitReferenceUpdated(Event event) { |
| if (event.getRefName().equals(RefNames.REFS_CONFIG)) { |
| Project.NameKey p = new Project.NameKey(event.getProjectName()); |
| try { |
| ProjectConfig oldCfg = parseConfig(p, event.getOldObjectId()); |
| ProjectConfig newCfg = parseConfig(p, event.getNewObjectId()); |
| |
| if (oldCfg != null && newCfg != null |
| && !oldCfg.getProject().getSubmitType().equals(newCfg.getProject().getSubmitType())) { |
| // submit type has changed |
| ... |
| } |
| } catch (IOException | ConfigInvalidException e) { |
| ... |
| } |
| } |
| } |
| |
| private ProjectConfig parseConfig(Project.NameKey p, String idStr) |
| throws IOException, ConfigInvalidException, RepositoryNotFoundException { |
| ObjectId id = ObjectId.fromString(idStr); |
| if (ObjectId.zeroId().equals(id)) { |
| return null; |
| } |
| return ProjectConfig.read(metaDataUpdateFactory.create(p), id); |
| } |
| } |
| ---- |
| |
| == Trace Event origin |
| |
| When plugins are installed in a multi-master setups it can be useful to know |
| the Gerrit `instanceId` of the server that has generated an Event. |
| |
| E.g. A plugin that sends an instance message for every comment on a change may |
| want to react only if the event is generated on the local Gerrit master, for |
| avoiding duplicating the notifications. |
| |
| If link:config-gerrit.html[instanceId] is set, each Event will contain its |
| origin in the `instanceId` field. |
| |
| Here and example of ref-updated JSON event payload with `instanceId`: |
| |
| [source,json] |
| ---- |
| { |
| "submitter": { |
| "name": "Administrator", |
| "email": "admin@example.com", |
| "username": "admin" |
| }, |
| "refUpdate": { |
| "oldRev": "a69fc95c7aad5ad41c618d31548b8af835d2959a", |
| "newRev": "31da6556d638a74e5370b62f83e8007f94abb7c6", |
| "refName": "refs/changes/01/1/meta", |
| "project": "test" |
| }, |
| "type": "ref-updated", |
| "eventCreatedOn": 1588849085, |
| "instanceId": "instance1" |
| } |
| ---- |
| |
| [[capabilities]] |
| == Plugin Owned Capabilities |
| |
| Plugins may provide their own capabilities and restrict usage of SSH |
| commands or `UiAction` to the users who are granted those capabilities. |
| |
| Plugins define the capabilities by overriding the `CapabilityDefinition` |
| abstract class: |
| |
| [source,java] |
| ---- |
| public class PrintHelloCapability extends CapabilityDefinition { |
| @Override |
| public String getDescription() { |
| return "Print Hello"; |
| } |
| } |
| ---- |
| |
| If no Guice modules are declared in the manifest, capability may |
| use auto-registration by providing an `@Export` annotation: |
| |
| [source,java] |
| ---- |
| @Export("printHello") |
| public class PrintHelloCapability extends CapabilityDefinition { |
| [...] |
| } |
| ---- |
| |
| Otherwise the capability must be bound in a plugin module: |
| |
| [source,java] |
| ---- |
| public class HelloWorldModule extends AbstractModule { |
| @Override |
| protected void configure() { |
| bind(CapabilityDefinition.class) |
| .annotatedWith(Exports.named("printHello")) |
| .to(PrintHelloCapability.class); |
| } |
| } |
| ---- |
| |
| With a plugin-owned capability defined in this way, it is possible to restrict |
| usage of an SSH command or `UiAction` to members of the group that were granted |
| this capability in the usual way, using the `RequiresCapability` annotation: |
| |
| [source,java] |
| ---- |
| @RequiresCapability("printHello") |
| @CommandMetaData(name="print", description="Print greeting in different languages") |
| public final class PrintHelloWorldCommand extends SshCommand { |
| [...] |
| } |
| ---- |
| |
| Or with `UiAction`: |
| |
| [source,java] |
| ---- |
| @RequiresCapability("printHello") |
| public class SayHelloAction extends UiAction<RevisionResource> |
| implements RestModifyView<RevisionResource, SayHelloAction.Input> { |
| [...] |
| } |
| ---- |
| |
| Capability scope was introduced to differentiate between plugin-owned |
| capabilities and core capabilities. Per default the scope of the |
| `@RequiresCapability` annotation is `CapabilityScope.CONTEXT`, that means: |
| |
| * when `@RequiresCapability` is used within a plugin the scope of the |
| capability is assumed to be that plugin. |
| |
| * If `@RequiresCapability` is used within the core Gerrit Code Review server |
| (and thus is outside of a plugin) the scope is the core server and will use |
| the `GlobalCapability` known to Gerrit Code Review server. |
| |
| If a plugin needs to use a core capability name (e.g. "administrateServer") |
| this can be specified by setting `scope = CapabilityScope.CORE`: |
| |
| [source,java] |
| ---- |
| @RequiresCapability(value = "administrateServer", scope = |
| CapabilityScope.CORE) |
| [...] |
| ---- |
| |
| [[ui_extension]] |
| == UI Extension |
| |
| [[panels]] |
| === Panels |
| |
| UI plugins can contribute panels to Gerrit screens. |
| |
| Gerrit screens define extension points where plugins can add GWT |
| panels with custom controls: |
| |
| * Change Screen: |
| ** `GerritUiExtensionPoint.CHANGE_SCREEN_HEADER`: |
| + |
| Panel will be shown in the header bar to the right of the change |
| status. |
| |
| ** `GerritUiExtensionPoint.CHANGE_SCREEN_HEADER_RIGHT_OF_BUTTONS`: |
| + |
| Panel will be shown in the header bar on the right side of the buttons. |
| |
| ** `GerritUiExtensionPoint.CHANGE_SCREEN_HEADER_RIGHT_OF_POP_DOWNS`: |
| + |
| Panel will be shown in the header bar on the right side of the pop down |
| buttons. |
| |
| ** `GerritUiExtensionPoint.CHANGE_SCREEN_BELOW_COMMIT_INFO_BLOCK`: |
| + |
| Panel will be shown below the commit info block. |
| |
| ** `GerritUiExtensionPoint.CHANGE_SCREEN_BELOW_CHANGE_INFO_BLOCK`: |
| + |
| Panel will be shown below the change info block. |
| |
| ** `GerritUiExtensionPoint.CHANGE_SCREEN_BELOW_RELATED_INFO_BLOCK`: |
| + |
| Panel will be shown below the related info block. |
| |
| ** `GerritUiExtensionPoint.CHANGE_SCREEN_HISTORY_RIGHT_OF_BUTTONS`: |
| + |
| Panel will be shown in the history bar on the right side of the buttons. |
| |
| ** The following parameters are provided: |
| *** `GerritUiExtensionPoint.Key.CHANGE_INFO`: |
| + |
| The link:rest-api-changes.html#change-info[ChangeInfo] entity for the |
| current change. |
| + |
| The link:rest-api-changes.html#revision-info[RevisionInfo] entity for |
| the current patch set. |
| |
| * Project Info Screen: |
| ** `GerritUiExtensionPoint.PROJECT_INFO_SCREEN_TOP`: |
| + |
| Panel will be shown at the top of the screen. |
| |
| ** `GerritUiExtensionPoint.PROJECT_INFO_SCREEN_BOTTOM`: |
| + |
| Panel will be shown at the bottom of the screen. |
| |
| ** The following parameters are provided: |
| *** `GerritUiExtensionPoint.Key.PROJECT_NAME`: |
| + |
| The name of the project. |
| |
| * User Password Screen: |
| ** `GerritUiExtensionPoint.PASSWORD_SCREEN_BOTTOM`: |
| + |
| Panel will be shown at the bottom of the screen. |
| |
| ** The following parameters are provided: |
| *** `GerritUiExtensionPoint.Key.ACCOUNT_INFO`: |
| + |
| The link:rest-api-accounts.html#account-info[AccountInfo] entity for |
| the current user. |
| |
| * User Preferences Screen: |
| ** `GerritUiExtensionPoint.PREFERENCES_SCREEN_BOTTOM`: |
| + |
| Panel will be shown at the bottom of the screen. |
| |
| ** The following parameters are provided: |
| *** `GerritUiExtensionPoint.Key.ACCOUNT_INFO`: |
| + |
| The link:rest-api-accounts.html#account-info[AccountInfo] entity for |
| the current user. |
| |
| * User Profile Screen: |
| ** `GerritUiExtensionPoint.PROFILE_SCREEN_BOTTOM`: |
| + |
| Panel will be shown at the bottom of the screen below the grid with the |
| profile data. |
| |
| ** The following parameters are provided: |
| *** `GerritUiExtensionPoint.Key.ACCOUNT_INFO`: |
| + |
| The link:rest-api-accounts.html#account-info[AccountInfo] entity for |
| the current user. |
| |
| Example panel: |
| [source,java] |
| ---- |
| public class MyPlugin extends PluginEntryPoint { |
| @Override |
| public void onPluginLoad() { |
| Plugin.get().panel(GerritUiExtensionPoint.CHANGE_SCREEN_BELOW_CHANGE_INFO_BLOCK, |
| "my_panel_name", |
| new Panel.EntryPoint() { |
| @Override |
| public void onLoad(Panel panel) { |
| panel.setWidget(new InlineLabel("My Panel for change " |
| + panel.getInt(GerritUiExtensionPoint.Key.CHANGE_ID, -1)); |
| } |
| }); |
| } |
| } |
| ---- |
| |
| Change Screen panel ordering may be specified in the |
| project config. Values may be either "plugin name" or |
| "plugin name"."panel name". |
| Panels not specified in the config will be added |
| to the end in load order. Panels specified in the config that |
| are not found will be ignored. |
| |
| Example config: |
| ---- |
| [extension-panels "CHANGE_SCREEN_BELOW_CHANGE_INFO_BLOCK"] |
| panel = helloworld.change_id |
| panel = myotherplugin |
| panel = myplugin.my_panel_name |
| ---- |
| |
| |
| |
| [[actions]] |
| === Actions |
| |
| Plugins can contribute UI actions on core Gerrit pages. This is useful |
| for workflow customization or exposing plugin functionality through the |
| UI in addition to SSH commands and the REST API. |
| |
| For instance a plugin to integrate Jira with Gerrit changes may |
| contribute a "File bug" button to allow filing a bug from the change |
| page or plugins to integrate continuous integration systems may |
| contribute a "Schedule" button to allow a CI build to be scheduled |
| manually from the patch set panel. |
| |
| Two different places on core Gerrit pages are supported: |
| |
| * Change screen |
| * Project info screen |
| |
| Plugins contribute UI actions by implementing the `UiAction` interface: |
| |
| [source,java] |
| ---- |
| @RequiresCapability("printHello") |
| class HelloWorldAction implements UiAction<RevisionResource>, |
| RestModifyView<RevisionResource, HelloWorldAction.Input> { |
| static class Input { |
| boolean french; |
| String message; |
| } |
| |
| private Provider<CurrentUser> user; |
| |
| @Inject |
| HelloWorldAction(Provider<CurrentUser> user) { |
| this.user = user; |
| } |
| |
| @Override |
| public String apply(RevisionResource rev, Input input) { |
| final String greeting = input.french |
| ? "Bonjour" |
| : "Hello"; |
| return String.format("%s %s from change %s, patch set %d!", |
| greeting, |
| Strings.isNullOrEmpty(input.message) |
| ? Objects.firstNonNull(user.get().getUserName(), "world") |
| : input.message, |
| rev.getChange().getId().toString(), |
| rev.getPatchSet().getPatchSetId()); |
| } |
| |
| @Override |
| public Description getDescription( |
| RevisionResource resource) { |
| return new Description() |
| .setLabel("Say hello") |
| .setTitle("Say hello in different languages"); |
| } |
| } |
| ---- |
| |
| Sometimes plugins may want to be able to change the state of a patch set or |
| change in the `UiAction.apply()` method and reflect these changes on the core |
| UI. For example a buildbot plugin which exposes a 'Schedule' button on the |
| patch set panel may want to disable that button after the build was scheduled |
| and update the tooltip of that button. But because of Gerrit's caching |
| strategy the following must be taken into consideration. |
| |
| The browser is allowed to cache the `UiAction` information until something on |
| the change is modified. More accurately the change row needs to be modified in |
| the database to have a more recent `lastUpdatedOn` or a new `rowVersion`, or |
| the +refs/meta/config+ of the project or any parents needs to change to a new |
| SHA-1. The ETag SHA-1 computation code can be found in the |
| `ChangeResource.getETag()` method. |
| |
| The easiest way to accomplish this is to update `lastUpdatedOn` of the change: |
| |
| [source,java] |
| ---- |
| @Override |
| public Object apply(RevisionResource rcrs, Input in) { |
| // schedule a build |
| [...] |
| // update change |
| try (BatchUpdate bu = batchUpdateFactory.create( |
| project.getNameKey(), user, TimeUtil.nowTs())) { |
| bu.addOp(change.getId(), new BatchUpdate.Op() { |
| @Override |
| public boolean updateChange(ChangeContext ctx) { |
| return true; |
| } |
| }); |
| bu.execute(); |
| } |
| [...] |
| } |
| ---- |
| |
| `UiAction` must be bound in a plugin module: |
| |
| [source,java] |
| ---- |
| public class Module extends AbstractModule { |
| @Override |
| protected void configure() { |
| install(new RestApiModule() { |
| @Override |
| protected void configure() { |
| post(REVISION_KIND, "say-hello") |
| .to(HelloWorldAction.class); |
| } |
| }); |
| } |
| } |
| ---- |
| |
| The module above must be declared in the `pom.xml` for Maven driven |
| plugins: |
| |
| [source,xml] |
| ---- |
| <manifestEntries> |
| <Gerrit-Module>com.googlesource.gerrit.plugins.cookbook.Module</Gerrit-Module> |
| </manifestEntries> |
| ---- |
| |
| or in the `BUILD` configuration file for Bazel driven plugins: |
| |
| [source,python] |
| ---- |
| manifest_entries = [ |
| 'Gerrit-Module: com.googlesource.gerrit.plugins.cookbook.Module', |
| ] |
| ---- |
| |
| In some use cases more user input must be gathered, for that `UiAction` can be |
| combined with the JavaScript API. This would display a small popup near the |
| activation button to gather additional input from the user. The JS file is |
| typically put in the `static` folder within the plugin's directory: |
| |
| [source,javascript] |
| ---- |
| Gerrit.install(function(self) { |
| function onSayHello(c) { |
| var f = c.textfield(); |
| var t = c.checkbox(); |
| var b = c.button('Say hello', {onclick: function(){ |
| c.call( |
| {message: f.value, french: t.checked}, |
| function(r) { |
| c.hide(); |
| window.alert(r); |
| c.refresh(); |
| }); |
| }}); |
| c.popup(c.div( |
| c.prependLabel('Greeting message', f), |
| c.br(), |
| c.label(t, 'french'), |
| c.br(), |
| b)); |
| f.focus(); |
| } |
| self.onAction('revision', 'say-hello', onSayHello); |
| }); |
| ---- |
| |
| The JS module must be exposed as a `WebUiPlugin` and bound as |
| an HTTP Module: |
| |
| [source,java] |
| ---- |
| public class HttpModule extends ServletModule { |
| @Override |
| protected void configureServlets() { |
| DynamicSet.bind(binder(), WebUiPlugin.class) |
| .toInstance(new JavaScriptPlugin("hello.js")); |
| } |
| } |
| ---- |
| |
| The HTTP module above must be declared in the `pom.xml` for Maven |
| driven plugins: |
| |
| [source,xml] |
| ---- |
| <manifestEntries> |
| <Gerrit-HttpModule>com.googlesource.gerrit.plugins.cookbook.HttpModule</Gerrit-HttpModule> |
| </manifestEntries> |
| ---- |
| |
| or in the `BUILD` configuration file for Bazel driven plugins |
| |
| [source,python] |
| ---- |
| manifest_entries = [ |
| 'Gerrit-HttpModule: com.googlesource.gerrit.plugins.cookbook.HttpModule', |
| ] |
| ---- |
| |
| If `UiAction` is annotated with the `@RequiresCapability` annotation, then the |
| capability check is done during the `UiAction` gathering, so the plugin author |
| doesn't have to set `UiAction.Description.setVisible()` explicitly in this |
| case. |
| |
| The following prerequisites must be met, to satisfy the capability check: |
| |
| * user is authenticated |
| * user is a member of a group which has the `Administrate Server` capability, or |
| * user is a member of a group which has the required capability |
| |
| The `apply` method is called when the button is clicked. If `UiAction` is |
| combined with JavaScript API (its own JavaScript function is provided), |
| then a popup dialog is normally opened to gather additional user input. |
| A new button is placed on the popup dialog to actually send the request. |
| |
| Every `UiAction` exposes a REST API endpoint. The endpoint from the example above |
| can be accessed from any REST client, i. e.: |
| |
| ---- |
| $ curl -X POST -H "Content-Type: application/json" \ |
| -d '{message: "François", french: true}' \ |
| --user joe:secret \ |
| http://host:port/a/changes/1/revisions/1/cookbook~say-hello |
| "Bonjour François from change 1, patch set 1!" |
| ---- |
| |
| A special case is to bind an endpoint without a view name. This is |
| particularly useful for `DELETE` requests: |
| |
| [source,java] |
| ---- |
| public class Module extends AbstractModule { |
| @Override |
| protected void configure() { |
| install(new RestApiModule() { |
| @Override |
| protected void configure() { |
| delete(PROJECT_KIND) |
| .to(DeleteProject.class); |
| } |
| }); |
| } |
| } |
| ---- |
| |
| For a `UiAction` bound this way, a JS API function can be provided. |
| |
| Currently only one restriction exists: per plugin only one `UiAction` |
| can be bound per resource without view name. To define a JS function |
| for the `UiAction`, "/" must be used as the name: |
| |
| [source,javascript] |
| ---- |
| Gerrit.install(function(self) { |
| function onDeleteProject(c) { |
| [...] |
| } |
| self.onAction('project', '/', onDeleteProject); |
| }); |
| ---- |
| |
| |
| [[action-visitor]] |
| === Action Visitors |
| |
| In addition to providing new actions, plugins can have fine-grained control |
| over the link:rest-api-changes.html#action-info[ActionInfo] map, modifying or |
| removing existing actions, including those contributed by core. |
| |
| Visitors are provided the link:rest-api-changes.html#action-info[ActionInfo], |
| which is mutable, along with copies of the |
| link:rest-api-changes.html#change-info[ChangeInfo] and |
| link:rest-api-changes.html#revision-info[RevisionInfo]. They can modify the |
| action, or return `false` to exclude it from the resulting map. |
| |
| These operations only affect the action buttons that are displayed in the UI; |
| the underlying REST API endpoints are not affected. Multiple plugins may |
| implement the visitor interface, but the order in which they are run is |
| undefined. |
| |
| For example, to exclude "Cherry-Pick" only from certain projects, and rename |
| "Abandon": |
| |
| [source,java] |
| ---- |
| public class MyActionVisitor implements ActionVisitor { |
| @Override |
| public boolean visit(String name, ActionInfo actionInfo, |
| ChangeInfo changeInfo) { |
| if (name.equals("abandon")) { |
| actionInfo.label = "Drop"; |
| } |
| return true; |
| } |
| |
| @Override |
| public boolean visit(String name, ActionInfo actionInfo, |
| ChangeInfo changeInfo, RevisionInfo revisionInfo) { |
| if (project.startsWith("some-team/") && name.equals("cherrypick")) { |
| return false; |
| } |
| return true; |
| } |
| } |
| ---- |
| |
| |
| [[top-menu-extensions]] |
| == Top Menu Extensions |
| |
| Plugins can contribute items to Gerrit's top menu. |
| |
| A single top menu extension can have multiple elements and will be put as |
| the last element in Gerrit's top menu. |
| |
| Plugins define the top menu entries by implementing `TopMenu` interface: |
| |
| [source,java] |
| ---- |
| public class MyTopMenuExtension implements TopMenu { |
| @Override |
| public List<MenuEntry> getEntries() { |
| return Lists.newArrayList( |
| new MenuEntry("Top Menu Entry", Lists.newArrayList( |
| new MenuItem("Gerrit", "http://gerrit.googlecode.com/")))); |
| } |
| } |
| ---- |
| |
| Plugins can also add additional menu items to Gerrit's top menu entries |
| by defining a `MenuEntry` that has the same name as a Gerrit top menu |
| entry: |
| |
| [source,java] |
| ---- |
| public class MyTopMenuExtension implements TopMenu { |
| @Override |
| public List<MenuEntry> getEntries() { |
| return Lists.newArrayList( |
| new MenuEntry(GerritTopMenu.PROJECTS, Lists.newArrayList( |
| new MenuItem("Browse Repositories", "https://gerrit.googlesource.com/")))); |
| } |
| } |
| ---- |
| |
| `MenuItems` that are bound for the `MenuEntry` with the name |
| `GerritTopMenu.PROJECTS` can contain a `${projectName}` placeholder |
| which is automatically replaced by the actual project name. |
| |
| E.g. plugins may register an link:#http[HTTP Servlet] to handle project |
| specific requests and add an menu item for this: |
| |
| [source,java] |
| ---- |
| new MenuItem("My Screen", "/plugins/myplugin/project/${projectName}"); |
| ---- |
| |
| This also enables plugins to provide menu items for project aware |
| screens: |
| |
| [source,java] |
| ---- |
| new MenuItem("My Screen", "/x/my-screen/for/${projectName}"); |
| ---- |
| |
| If no Guice modules are declared in the manifest, the top menu extension may use |
| auto-registration by providing an `@Listen` annotation: |
| |
| [source,java] |
| ---- |
| @Listen |
| public class MyTopMenuExtension implements TopMenu { |
| [...] |
| } |
| ---- |
| |
| Otherwise the top menu extension must be bound in the plugin module used |
| for the Gerrit system injector (Gerrit-Module entry in MANIFEST.MF): |
| |
| [source,java] |
| ---- |
| package com.googlesource.gerrit.plugins.helloworld; |
| |
| public class HelloWorldModule extends AbstractModule { |
| @Override |
| protected void configure() { |
| DynamicSet.bind(binder(), TopMenu.class).to(MyTopMenuExtension.class); |
| } |
| } |
| ---- |
| |
| [source,manifest] |
| ---- |
| Gerrit-ApiType: plugin |
| Gerrit-Module: com.googlesource.gerrit.plugins.helloworld.HelloWorldModule |
| ---- |
| |
| It is also possible to show some menu entries only if the user has a |
| certain capability: |
| |
| [source,java] |
| ---- |
| public class MyTopMenuExtension implements TopMenu { |
| private final String pluginName; |
| private final Provider<CurrentUser> userProvider; |
| private final List<MenuEntry> menuEntries; |
| |
| @Inject |
| public MyTopMenuExtension(@PluginName String pluginName, |
| Provider<CurrentUser> userProvider) { |
| this.pluginName = pluginName; |
| this.userProvider = userProvider; |
| menuEntries = new ArrayList<TopMenu.MenuEntry>(); |
| |
| // add menu entry that is only visible to users with a certain capability |
| if (canSeeMenuEntry()) { |
| menuEntries.add(new MenuEntry("Top Menu Entry", Collections |
| .singletonList(new MenuItem("Gerrit", "http://gerrit.googlecode.com/")))); |
| } |
| |
| // add menu entry that is visible to all users (even anonymous users) |
| menuEntries.add(new MenuEntry("Top Menu Entry", Collections |
| .singletonList(new MenuItem("Documentation", "/plugins/myplugin/")))); |
| } |
| |
| private boolean canSeeMenuEntry() { |
| if (userProvider.get().isIdentifiedUser()) { |
| CapabilityControl ctl = userProvider.get().getCapabilities(); |
| return ctl.canPerform(pluginName + "-" + MyCapability.ID) |
| || ctl.canAdministrateServer(); |
| } else { |
| return false; |
| } |
| } |
| |
| @Override |
| public List<MenuEntry> getEntries() { |
| return menuEntries; |
| } |
| } |
| ---- |
| |
| |
| [[settings-screen]] |
| == Plugin Settings Screen |
| |
| If a plugin implements a screen for administrating its settings that is |
| available under "#/x/<plugin-name>/settings" it is automatically linked |
| from the plugin list screen. |
| |
| [[http]] |
| == HTTP Servlets |
| |
| Plugins or extensions may register additional HTTP servlets, and |
| wrap them with HTTP filters. |
| |
| Servlets may use auto-registration to declare the URL they handle: |
| |
| [source,java] |
| ---- |
| import com.google.gerrit.extensions.annotations.Export; |
| import com.google.inject.Singleton; |
| import javax.servlet.http.HttpServlet; |
| import javax.servlet.http.HttpServletRequest; |
| import javax.servlet.http.HttpServletResponse; |
| |
| @Export("/print") |
| @Singleton |
| class HelloServlet extends HttpServlet { |
| protected void doGet(HttpServletRequest req, HttpServletResponse res) throws IOException { |
| res.setContentType("text/plain"); |
| res.setCharacterEncoding("UTF-8"); |
| res.getWriter().write("Hello"); |
| } |
| } |
| ---- |
| |
| The auto registration only works for standard servlet mappings like |
| `/foo` or `+/foo/*+`. Regex style bindings must use a Guice ServletModule |
| to register the HTTP servlets and declare it explicitly in the manifest |
| with the `Gerrit-HttpModule` attribute: |
| |
| [source,java] |
| ---- |
| import com.google.inject.servlet.ServletModule; |
| |
| class MyWebUrls extends ServletModule { |
| protected void configureServlets() { |
| serve("/print").with(HelloServlet.class); |
| } |
| } |
| ---- |
| |
| For a plugin installed as name `helloworld`, the servlet implemented |
| by HelloServlet class will be available to users as: |
| |
| ---- |
| $ curl http://review.example.com/plugins/helloworld/print |
| ---- |
| |
| [[data-directory]] |
| == Data Directory |
| |
| Plugins can request a data directory with a `@PluginData` Path (or File, |
| deprecated) dependency. A data directory will be created automatically |
| by the server in `$site_path/data/$plugin_name` and passed to the |
| plugin. |
| |
| Plugins can use this to store any data they want. |
| |
| [source,java] |
| ---- |
| @Inject |
| MyType(@PluginData java.nio.file.Path myDir) { |
| this.in = Files.newInputStream(myDir.resolve("my.config")); |
| } |
| ---- |
| |
| [[secure-store]] |
| == SecureStore |
| |
| SecureStore allows to change the way Gerrit stores sensitive data like |
| passwords. |
| |
| In order to replace the default SecureStore (no-op) implementation, |
| a class that extends `com.google.gerrit.server.securestore.SecureStore` |
| needs to be provided (with dependencies) in a separate jar file. Then |
| link:pgm-SwitchSecureStore.html[SwitchSecureStore] must be run to |
| switch implementations. |
| |
| The SecureStore implementation is instantiated using a Guice injector |
| which binds the `File` annotated with the `@SitePath` annotation. |
| This means that a SecureStore implementation class can get access to |
| the `site_path` like in the following example: |
| |
| [source,java] |
| ---- |
| @Inject |
| MySecureStore(@SitePath java.io.File sitePath) { |
| // your code |
| } |
| ---- |
| |
| No Guice bindings or modules are required. Gerrit will automatically |
| discover and bind the implementation. |
| |
| [[gerrit-replica]] |
| == Gerrit Replica |
| |
| Gerrit can be run as a read-only replica. Some plugins may need to know |
| whether Gerrit is run as a primary- or a replica instance. For that purpose |
| Gerrit exposes the `@GerritIsReplica` annotation. A boolean annotated with |
| this annotation will indicate whether Gerrit is run as a replica. |
| |
| [[accountcreation]] |
| == Account Creation |
| |
| Plugins can hook into the |
| link:rest-api-accounts.html#create-account[account creation] REST API and |
| inject additional external identifiers for an account that represents a user |
| in some external user store. For that, an implementation of the extension |
| point `com.google.gerrit.server.account.AccountExternalIdCreator` |
| must be registered. |
| |
| [source,java] |
| ---- |
| class MyExternalIdCreator implements AccountExternalIdCreator { |
| @Override |
| public List<AccountExternalId> create(Account.Id id, String username, |
| String email) { |
| // your code |
| } |
| } |
| |
| bind(AccountExternalIdCreator.class) |
| .annotatedWith(UniqueAnnotations.create()) |
| .to(MyExternalIdCreator.class); |
| ---- |
| |
| [[download-commands]] |
| == Download Commands |
| |
| Gerrit offers commands for downloading changes and cloning projects |
| using different download schemes (e.g. for downloading via different |
| network protocols). Plugins can contribute download schemes, download |
| commands and clone commands by implementing |
| `com.google.gerrit.extensions.config.DownloadScheme`, |
| `com.google.gerrit.extensions.config.DownloadCommand` and |
| `com.google.gerrit.extensions.config.CloneCommand`. |
| |
| The download schemes, download commands and clone commands which are |
| used most often are provided by the Gerrit core plugin |
| `download-commands`. |
| |
| [[included-in]] |
| == Included In |
| |
| For merged changes the link:user-review-ui.html#included-in[Included In] |
| drop-down panel shows the branches and tags in which the change is |
| included. |
| |
| Plugins can add additional systems in which the change can be included |
| by implementing `com.google.gerrit.extensions.config.ExternalIncludedIn`, |
| e.g. a plugin can provide a list of servers on which the change was |
| deployed. |
| |
| [[change-report-formatting]] |
| == Change Report Formatting |
| |
| When a change is pushed for review from the command line, Gerrit reports |
| the change(s) received with their URL and subject. |
| |
| By implementing the |
| `com.google.gerrit.server.git.ChangeReportFormatter` interface, a plugin |
| may change the formatting of the report. |
| |
| [[url-formatting]] |
| == URL Formatting |
| |
| URLs to various parts of Gerrit are usually formed by adding suffixes to |
| the canonical web URL. |
| |
| By implementing the |
| `com.google.gerrit.server.config.UrlFormatter` interface, a plugin may |
| change the format of the URL. |
| |
| [[links-to-external-tools]] |
| == Links To External Tools |
| |
| Gerrit has extension points that enables development of a |
| light-weight plugin that links commits to external |
| tools (GitBlit, CGit, company specific resources etc). |
| |
| PatchSetWebLinks will appear to the right of the commit-SHA1 in the UI. |
| |
| [source, java] |
| ---- |
| import com.google.gerrit.extensions.annotations.Listen; |
| import com.google.gerrit.extensions.webui.PatchSetWebLink;; |
| import com.google.gerrit.extensions.webui.WebLinkTarget; |
| |
| @Listen |
| public class MyWeblinkPlugin implements PatchSetWebLink { |
| private String name = "MyLink"; |
| private String placeHolderUrlProjectCommit = "http://my.tool.com/project=%s/commit=%s"; |
| private String imageUrl = "http://placehold.it/16x16.gif"; |
| |
| @Override |
| public WebLinkInfo getPatchSetWebLink(String projectName, String commit) { |
| return new WebLinkInfo(name, |
| imageUrl, |
| String.format(placeHolderUrlProjectCommit, project, commit), |
| WebLinkTarget.BLANK); |
| } |
| } |
| ---- |
| |
| ParentWebLinks will appear to the right of the SHA1 of the parent |
| revisions in the UI. The implementation should in most use cases direct |
| to the same external service as PatchSetWebLink; it is provided as a |
| separate interface because not all users want to have links for the |
| parent revisions. |
| |
| FileWebLinks will appear in the side-by-side diff screen on the right |
| side of the patch selection on each side. |
| |
| DiffWebLinks will appear in the side-by-side and unified diff screen in |
| the header next to the navigation icons. |
| |
| ProjectWebLinks will appear in the project list in the |
| `Repository Browser` column. |
| |
| BranchWebLinks will appear in the branch list in the last column. |
| |
| FileHistoryWebLinks will appear on the access rights screen. |
| |
| TagWebLinks will appear in the tag list in the last column. |
| |
| If a `get*WebLink` implementation returns `null`, the link will be omitted. This |
| allows the plugin to selectively "enable" itself on a per-project/branch/file |
| basis. |
| |
| [[lfs-extension]] |
| == LFS Storage Plugins |
| |
| Gerrit provides an extension point that enables development of |
| link:https://github.com/github/git-lfs/blob/master/docs/api/v1/http-v1-batch.md[ |
| LFS (Large File Storage),role=external,window=_blank] storage plugins. Gerrit core exposes the default LFS |
| protocol endpoint `<project-name>/info/lfs/objects/batch` and forwards the requests |
| to the configured link:config-gerrit.html#lfs[lfs.plugin] plugin which implements |
| the LFS protocol. By exposing the default LFS endpoint, the git-lfs client can be |
| used without any configuration. |
| |
| [source, java] |
| ---- |
| /** Provide an LFS protocol implementation */ |
| import org.eclipse.jgit.lfs.server.LargeFileRepository; |
| import org.eclipse.jgit.lfs.server.LfsProtocolServlet; |
| |
| @Singleton |
| public class LfsApiServlet extends LfsProtocolServlet { |
| private static final long serialVersionUID = 1L; |
| |
| private final S3LargeFileRepository repository; |
| |
| @Inject |
| LfsApiServlet(S3LargeFileRepository repository) { |
| this.repository = repository; |
| } |
| |
| @Override |
| protected LargeFileRepository getLargeFileRepository() { |
| return repository; |
| } |
| } |
| |
| /** Register the LfsApiServlet to listen on the default LFS protocol endpoint */ |
| import static com.google.gerrit.httpd.plugins.LfsPluginServlet.URL_REGEX; |
| |
| import com.google.inject.servlet.ServletModule; |
| |
| public class HttpModule extends ServletModule { |
| @Override |
| protected void configureServlets() { |
| serveRegex(URL_REGEX).with(LfsApiServlet.class); |
| } |
| } |
| |
| /** Provide an implementation of the LargeFileRepository */ |
| import org.eclipse.jgit.lfs.server.s3.S3Repository; |
| |
| public class S3LargeFileRepository extends S3Repository { |
| ... |
| } |
| ---- |
| |
| [[metrics]] |
| == Metrics |
| |
| === Metrics Reporting |
| |
| To send Gerrit's metrics data to an external reporting backend, a plugin can |
| get a `MetricRegistry` injected and register an instance of a class that |
| implements the `Reporter` interface from link:http://metrics.dropwizard.io/[ |
| DropWizard Metrics,role=external,window=_blank]. |
| |
| Metric reporting plugin implementations are provided for |
| link:https://gerrit.googlesource.com/plugins/metrics-reporter-jmx/[JMX,role=external,window=_blank], |
| link:https://gerrit.googlesource.com/plugins/metrics-reporter-elasticsearch/[Elastic Search,role=external,window=_blank], |
| and link:https://gerrit.googlesource.com/plugins/metrics-reporter-graphite/[Graphite,role=external,window=_blank]. |
| |
| There is also a working example of reporting metrics to the console in the |
| link:https://gerrit.googlesource.com/plugins/cookbook-plugin/+/master/src/main/java/com/googlesource/gerrit/plugins/cookbook/ConsoleMetricReporter.java[ |
| cookbook plugin,role=external,window=_blank]. |
| |
| === Providing own metrics |
| |
| Plugins may provide metrics to be dispatched to external reporting services by |
| getting a `MetricMaker` injected and creating instances of specific types of |
| metric: |
| |
| * Counter |
| + |
| Metric whose value increments during the life of the process. |
| |
| * Timer |
| + |
| Metric recording time spent on an operation. |
| |
| * Histogram |
| + |
| Metric recording statistical distribution (rate) of values. |
| |
| Note that metrics cannot be recorded from plugin init steps that |
| are run during site initialization. |
| |
| By default, plugin metrics are recorded under |
| `plugins/${plugin-name}/${metric-name}`. This can be changed by |
| setting `plugins.${plugin-name}.metricsPrefix` in the `gerrit.config` |
| file. For example: |
| |
| ---- |
| [plugin "my-plugin"] |
| metricsPrefix = my-metrics |
| ---- |
| |
| will cause the metrics to be recorded under `my-metrics/${metric-name}`. |
| |
| See the replication metrics in the |
| link:https://gerrit.googlesource.com/plugins/replication/+/master/src/main/java/com/googlesource/gerrit/plugins/replication/ReplicationMetrics.java[ |
| replication plugin,role=external,window=_blank] for an example of usage. |
| |
| [[account-patch-review-store]] |
| == AccountPatchReviewStore |
| |
| The AccountPatchReviewStore is used to store reviewed flags on changes. |
| A reviewed flag is a tuple of (patch set ID, file, account ID) and |
| records whether the user has reviewed a file in a patch set. Each user |
| can easily have thousands of reviewed flags and the number of reviewed |
| flags is growing without bound. The store must be able handle this data |
| volume efficiently. |
| |
| Gerrit implements this extension point, but plugins may bind another |
| implementation, e.g. one that supports cluster setup with multiple |
| primary Gerrit nodes handling write operations. |
| |
| [source,java] |
| ---- |
| DynamicItem.bind(binder(), AccountPatchReviewStore.class) |
| .to(MultiMasterAccountPatchReviewStore.class); |
| |
| ... |
| |
| public class MultiMasterAccountPatchReviewStore |
| implements AccountPatchReviewStore { |
| ... |
| } |
| ---- |
| |
| |
| [[documentation]] |
| == Documentation |
| |
| If a plugin does not register a filter or servlet to handle URLs |
| `+/Documentation/*+` or `+/static/*+`, the core Gerrit server will |
| automatically export these resources over HTTP from the plugin JAR. |
| |
| Static resources under the `static/` directory in the JAR will be |
| available as `/plugins/helloworld/static/resource`. This prefix is |
| configurable by setting the `Gerrit-HttpStaticPrefix` attribute. |
| |
| Documentation files under the `Documentation/` directory in the JAR |
| will be available as `/plugins/helloworld/Documentation/resource`. This |
| prefix is configurable by setting the `Gerrit-HttpDocumentationPrefix` |
| attribute. |
| |
| Documentation may be written in the Markdown flavor |
| link:https://github.com/vsch/flexmark-java[flexmark-java,role=external,window=_blank] |
| if the file name ends with `.md`. Gerrit will automatically convert |
| Markdown to HTML if accessed with extension `.html`. |
| |
| [[macros]] |
| Within the Markdown documentation files macros can be used that allow |
| to write documentation with reasonably accurate examples that adjust |
| automatically based on the installation. |
| |
| The following macros are supported: |
| |
| [width="40%",options="header"] |
| |=================================================== |
| |Macro | Replacement |
| |@PLUGIN@ | name of the plugin |
| |@URL@ | Gerrit Web URL |
| |@SSH_HOST@ | SSH Host |
| |@SSH_PORT@ | SSH Port |
| |=================================================== |
| |
| The macros will be replaced when the documentation files are rendered |
| from Markdown to HTML. |
| |
| Macros that start with `\` such as `\@KEEP@` will render as `@KEEP@` |
| even if there is an expansion for `KEEP` in the future. |
| |
| [[auto-index]] |
| === Automatic Index |
| |
| If a plugin does not handle its `/` URL itself, Gerrit will |
| redirect clients to the plugin's `/Documentation/index.html`. |
| Requests for `/Documentation/` (bare directory) will also redirect |
| to `/Documentation/index.html`. |
| |
| If neither resource `Documentation/index.html` or |
| `Documentation/index.md` exists in the plugin JAR, Gerrit will |
| automatically generate an index page for the plugin's documentation |
| tree by scanning every `*.md` and `*.html` file in the Documentation/ |
| directory. |
| |
| For any discovered Markdown (`*.md`) file, Gerrit will parse the |
| header of the file and extract the first level one title. This |
| title text will be used as display text for a link to the HTML |
| version of the page. |
| |
| For any discovered HTML (`*.html`) file, Gerrit will use the name |
| of the file, minus the `*.html` extension, as the link text. Any |
| hyphens in the file name will be replaced with spaces. |
| |
| If a discovered file is named `about.md` or `about.html`, its |
| content will be inserted in an 'About' section at the top of the |
| auto-generated index page. If both `about.md` and `about.html` |
| exist, only the first discovered file will be used. |
| |
| If a discovered file name beings with `cmd-` it will be clustered |
| into a 'Commands' section of the generated index page. |
| |
| If a discovered file name beings with `servlet-` it will be clustered |
| into a 'Servlets' section of the generated index page. |
| |
| If a discovered file name beings with `rest-api-` it will be clustered |
| into a 'REST APIs' section of the generated index page. |
| |
| All other files are clustered under a 'Documentation' section. |
| |
| Some optional information from the manifest is extracted and |
| displayed as part of the index page, if present in the manifest: |
| |
| [width="40%",options="header"] |
| |=================================================== |
| |Field | Source Attribute |
| |Name | Implementation-Title |
| |Vendor | Implementation-Vendor |
| |Version | Implementation-Version |
| |URL | Implementation-URL |
| |API Version | Gerrit-ApiVersion |
| |=================================================== |
| |
| [[deployment]] |
| == Deployment |
| |
| Compiled plugins and extensions can be deployed to a running Gerrit |
| server using the link:cmd-plugin-install.html[plugin install] command. |
| |
| Web UI plugins distributed as a single `.js` file (or `.html` file for |
| Polygerrit) can be deployed without the overhead of JAR packaging. For |
| more information refer to link:cmd-plugin-install.html[plugin install] |
| command. |
| |
| Plugins can also be copied directly into the server's directory at |
| `$site_path/plugins/$name.(jar|js|html)`. For Web UI plugins, the name |
| of the file, minus the `.js` or `.html` extension, will be used as the |
| plugin name. For JAR plugins, the value of the `Gerrit-PluginName` |
| manifest attribute will be used, if provided, otherwise the name of |
| the file, minus the `.jar` extension, will be used. |
| |
| For Web UI plugins, the plugin version is derived from the filename. |
| If the filename contains one or more hyphens, the version is taken |
| from the portion following the last hyphen. For example if the plugin |
| filename is `my-plugin-1.0.js` the version will be `1.0`. For JAR |
| plugins, the version is taken from the `Version` attribute in the |
| manifest. |
| |
| Unless disabled, servers periodically scan the `$site_path/plugins` |
| directory for updated plugins. The time can be adjusted by |
| link:config-gerrit.html#plugins.checkFrequency[plugins.checkFrequency]. |
| |
| For disabling plugins the link:cmd-plugin-remove.html[plugin remove] |
| command can be used. |
| |
| Disabled plugins can be re-enabled using the |
| link:cmd-plugin-enable.html[plugin enable] command. |
| |
| [[reviewer-suggestion]] |
| == Reviewer Suggestion Plugins |
| |
| Gerrit provides an extension point that enables Plugins to rank |
| the list of reviewer suggestion a user receives upon clicking "Add Reviewer" on |
| the change screen. |
| |
| Gerrit supports both a default suggestion that appears when the user has not yet |
| typed anything and a filtered suggestion that is shown as the user starts |
| typing. |
| |
| Plugins receive a candidate list and can return a `Set` of suggested reviewers |
| containing the `Account.Id` and a score for each reviewer. The candidate list is |
| non-binding and plugins can choose to return reviewers not initially contained in |
| the candidate list. |
| |
| Server administrators can configure the overall weight of each plugin by setting |
| the `addreviewer.pluginName-exportName.weight` value in `gerrit.config`. |
| |
| [source, java] |
| ---- |
| import com.google.gerrit.common.Nullable; |
| import com.google.gerrit.entities.Account; |
| import com.google.gerrit.entities.Change; |
| import com.google.gerrit.entities.Project; |
| import com.google.gerrit.extensions.annotations.ExtensionPoint; |
| |
| import java.util.Set; |
| |
| public class MyPlugin implements ReviewerSuggestion { |
| public Set<SuggestedReviewer> suggestReviewers(Project.NameKey project, |
| @Nullable Change.Id changeId, @Nullable String query, |
| Set<Account.Id> candidates) { |
| Set<SuggestedReviewer> suggestions = new HashSet<>(); |
| // Implement your ranking logic here |
| return suggestions; |
| } |
| } |
| ---- |
| |
| |
| [[mail-filter]] |
| == Mail Filter Plugins |
| |
| Gerrit provides an extension point that enables Plugins to discard incoming |
| messages and prevent further processing by Gerrit. |
| |
| This can be used to implement spam checks, signature validations or organization |
| specific checks like IP filters. |
| |
| [source, java] |
| ---- |
| import com.google.gerrit.extensions.annotations.ExtensionPoint; |
| import com.google.gerrit.mail.MailMessage; |
| |
| public class MyPlugin implements MailFilter { |
| public boolean shouldProcessMessage(MailMessage message) { |
| // Implement your filter logic here |
| return true; |
| } |
| } |
| ---- |
| |
| [[ssh-command-creation-interception]] |
| == SSH Command Creation Interception |
| |
| Gerrit provides an extension point that allows a plugin to intercept |
| creation of SSH commands and override the functionality with its own |
| implementation. |
| |
| [source, java] |
| ---- |
| import com.google.gerrit.sshd.SshCreateCommandInterceptor; |
| |
| class MyCommandInterceptor implements SshCreateCommandInterceptor { |
| @Override |
| public String intercept(String in) { |
| return pluginName + " mycommand"; |
| } |
| } |
| ---- |
| |
| [[ssh-command-execution-interception]] |
| == SSH Command Execution Interception |
| Gerrit provides an extension point that enables plugins to check and |
| prevent an SSH command from being run. |
| |
| [source, java] |
| ---- |
| import com.google.gerrit.sshd.SshExecuteCommandInterceptor; |
| |
| @Singleton |
| public class SshExecuteCommandInterceptorImpl implements SshExecuteCommandInterceptor { |
| private final Provider<SshSession> sessionProvider; |
| |
| @Inject |
| SshExecuteCommandInterceptorImpl(Provider<SshSession> sessionProvider) { |
| this.sessionProvider = sessionProvider; |
| } |
| |
| @Override |
| public boolean accept(String command, List<String> arguments) { |
| if (command.startsWith("gerrit") && !"10.1.2.3".equals(sessionProvider.get().getRemoteAddressAsString())) { |
| return false; |
| } |
| return true; |
| } |
| } |
| ---- |
| |
| And then declare it in your SSH module: |
| [source, java] |
| ---- |
| DynamicSet.bind(binder(), SshExecuteCommandInterceptor.class) |
| .to(SshExecuteCommandInterceptorImpl.class); |
| ---- |
| |
| [[pre-submit-evaluator]] |
| == Pre-submit Validation Plugins |
| |
| Gerrit provides an extension point that enables plugins to prevent a change |
| from being submitted. |
| |
| [IMPORTANT] |
| This extension point **must NOT** be used for long or slow operations, like |
| calling external programs or content, running unit tests... |
| Slow operations will hurt the whole Gerrit instance. |
| |
| This can be used to implement custom rules that changes have to match to become |
| submittable. A more concrete example: the Prolog rules engine can be |
| implemented using this. |
| |
| Gerrit calls the plugins once per change and caches the results. Although it is |
| possible to predict when this interface will be triggered, this should not be |
| considered as a feature. Plugins should only rely on the internal state of the |
| ChangeData, not on external values like date and time, remote content or |
| randomness. |
| |
| Plugins are expected to support rules inheritance themselves, providing ways |
| to configure it and handling the logic behind it. |
| Please note that no inheritance is sometimes better than badly handled |
| inheritance: mis-communication and strange behaviors caused by inheritance |
| may and will confuse the users. Each plugins is responsible for handling the |
| project hierarchy and taking wise actions. Gerrit does not enforce it. |
| |
| Once Gerrit has gathered every plugins' SubmitRecords, it stores them. |
| |
| Plugins accept or reject a given change using `SubmitRecord.Status`. |
| If a change is ready to be submitted, `OK`. If it is not ready and requires |
| modifications, `NOT_READY`. Other statuses are available for particular cases. |
| A change can be submitted if all the plugins accept the change. |
| |
| Plugins may also decide not to vote on a given change by returning an |
| `Optional.empty()` (ie: the plugin is not enabled for this repository). |
| |
| If a plugin decides not to vote, it's name will not be displayed in the UI and |
| it will not be recoded in the database. |
| |
| .Gerrit's Pre-submit handling with three plugins |
| [width="50%",cols="^m,^m,^m,^m",frame="topbot",options="header"] |
| |======================================================= |
| | Plugin A | Plugin B | Plugin C | Final decision |
| | OK | OK | OK | OK |
| | OK | OK | / | OK |
| | OK | OK | RULE_ERROR | NOT_READY |
| | OK | NOT_READY | OK | NOT_READY |
| | NOT_READY | OK | OK | NOT_READY |
| |======================================================= |
| |
| |
| This makes composing plugins really easy. |
| |
| - If a plugin places a veto on a change, it can't be submitted. |
| - If a plugin isn't enabled for a project (or isn't needed for this change), |
| it returns an empty collection. |
| - If all the plugins answer `OK`, the change can be submitted. |
| |
| |
| A more rare case, but worth documenting: if there are no installed plugins, |
| the labels will be compared to the rules defined in the project's config, |
| and the permission system will be used to allow or deny a submit request. |
| |
| Some rules are defined internally to provide a common base ground (and sanity): |
| changes that are marked as WIP or that are closed (abandoned, merged) can't be merged. |
| |
| |
| [source, java] |
| ---- |
| import java.util.Optional; |
| import com.google.gerrit.common.data.SubmitRecord; |
| import com.google.gerrit.common.data.SubmitRecord.Status; |
| import com.google.gerrit.server.query.change.ChangeData; |
| import com.google.gerrit.server.rules.SubmitRule; |
| |
| public class MyPluginRules implements SubmitRule { |
| public Optional<SubmitRecord> evaluate(ChangeData changeData) { |
| // Implement your submitability logic here |
| |
| // Assuming we want to prevent this change from being submitted: |
| SubmitRecord record = new SubmitRecord(); |
| record.status = Status.NOT_READY; |
| return Optional.of(record); |
| } |
| } |
| ---- |
| |
| Don't forget to register your class! |
| |
| [source, java] |
| ---- |
| import com.google.gerrit.extensions.annotations.Exports; |
| import com.google.inject.AbstractModule; |
| |
| public class MyPluginModule extends AbstractModule { |
| @Override |
| protected void configure() { |
| bind(SubmitRule.class).annotatedWith(Exports.named("myPlugin")).to(MyPluginRules.class); |
| } |
| } |
| ---- |
| |
| Plugin authors should also consider binding their SubmitRule using a `Gerrit-BatchModule`. |
| See link:dev-plugins.html[Batch runtime] for more informations. |
| |
| |
| The SubmitRule extension point allows you to write complex rules, but writing |
| small self-contained rules should be preferred: doing so allows end users to |
| compose several rules to form more complex submit checks. |
| |
| The `SubmitRequirement` class allows rules to communicate what the user needs |
| to change in order to be compliant. These requirements should be kept once they |
| are met, but marked as `OK`. If the requirements were not displayed, reviewers |
| would need to use their precious time to manually check that they were met. |
| |
| Implementors of the `SubmitRule` interface should check whether they need to |
| contribute to the link:#change-etag-computation[change ETag computation] to |
| prevent callers using ETags from potentially seeing outdated submittability |
| information. |
| |
| [[change-etag-computation]] |
| == Change ETag Computation |
| |
| By implementing the `com.google.gerrit.server.change.ChangeETagComputation` |
| interface plugins can contribute a value to the change ETag computation. |
| |
| Plugins can affect the result of the get change / get change details REST |
| endpoints by: |
| |
| * providing link:#query_attributes[plugin defined attributes] in |
| link:rest-api-changes.html#change-info[ChangeInfo] |
| * implementing a link:#pre-submit-evaluator[pre-submit evaluator] which affects |
| the computation of `submittable` field in |
| link:rest-api-changes.html#change-info[ChangeInfo] |
| |
| If the plugin defined part of link:rest-api-changes.html#change-info[ |
| ChangeInfo] depends on plugin specific data, callers that use change ETags to |
| avoid unneeded recomputations of ChangeInfos may see outdated plugin attributes |
| and/or outdated submittable information, because a ChangeInfo is only reloaded |
| if the change ETag changes. |
| |
| By implementating the `com.google.gerrit.server.change.ChangeETagComputation` |
| interface plugins can contribute to the ETag computation and thus ensure that |
| the change ETag changes when the plugin data was changed. This way it can be |
| ensured that callers do not see outdated ChangeInfos. |
| |
| IMPORTANT: Change ETags are computed very frequently and the computation must |
| be cheap. Take good care to not perform any expensive computations when |
| implementing this. |
| |
| [source, java] |
| ---- |
| import static java.nio.charset.StandardCharsets.UTF_8; |
| |
| import com.google.common.hash.Hasher; |
| import com.google.gerrit.entities.Change; |
| import com.google.gerrit.entities.Project; |
| import com.google.gerrit.server.change.ChangeETagComputation; |
| |
| public class MyPluginChangeETagComputation implements ChangeETagComputation { |
| public String getETag(Project.NameKey projectName, Change.Id changeId) { |
| Hasher hasher = Hashing.murmur3_128().newHasher(); |
| |
| // Add hashes for all plugin-specific data that affects change infos. |
| hasher.putString(sha1OfPluginSpecificChangeRef, UTF_8); |
| |
| return hasher.hash().toString(); |
| } |
| } |
| ---- |
| |
| [[exception-hook]] |
| == ExceptionHook |
| |
| An `ExceptionHook` allows implementors to control how certain |
| exceptions should be handled. |
| |
| This interface is intended to be implemented for multi-master setups to |
| control the behavior for handling exceptions that are thrown by a lower |
| layer that handles the consensus and synchronization between different |
| server nodes. E.g. if an operation fails because consensus for a Git |
| update could not be achieved (e.g. due to slow responding server nodes) |
| this interface can be used to retry the request instead of failing it |
| immediately. |
| |
| It also allows implementors to group exceptions that have the same |
| cause into one metric bucket. |
| |
| [[mail-soy-template-provider]] |
| == MailSoyTemplateProvider |
| |
| This extension point allows to provide soy templates for registration |
| so that they can be used for sending emails from a plugin. |
| |
| [[quota-enforcer]] |
| == Quota Enforcer |
| |
| Gerrit provides an extension point that allows a plugin to enforce quota. |
| link:quota.html[This documentation page] has a list of all quota requests that |
| Gerrit core issues. Plugins can choose to respond to all or just a subset of |
| requests. Some implementations might want to keep track of user quota in buckets, |
| others might just check against instance or project state to enforce limits on how |
| many projects can be created or how large a repository can become. |
| |
| Checking against instance state can be racy for concurrent requests as the server does not |
| refill tokens if the action fails in a later stage (e.g. database failure). If |
| plugins want to guarantee an absolute maximum on a resource, they have to do their own |
| book-keeping. |
| |
| [source, java] |
| ---- |
| import com.google.server.quota.QuotaEnforcer; |
| |
| class ProjectLimiter implements QuotaEnforcer { |
| private final long maxNumberOfProjects = 100; |
| @Override |
| QuotaResponse requestTokens(String quotaGroup, QuotaRequestContext ctx, long numTokens) { |
| if (!"/projects/create".equals(quotaGroup)) { |
| return QuotaResponse.noOp(); |
| } |
| // No deduction because we always check against the instance state (racy but fine for |
| // this plugin) |
| if (currentNumberOfProjects() + numTokens > maxNumberOfProjects) { |
| return QuotaResponse.error("too many projects"); |
| } |
| return QuotaResponse.ok(); |
| } |
| |
| @Override |
| QuotaResponse dryRun(String quotaGroup, QuotaRequestContext ctx, long numTokens) { |
| // Since we are not keeping any state in this enforcer, we can simply call requestTokens(). |
| return requestTokens(quotaGroup, ctx, numTokens); |
| } |
| |
| void refill(String quotaGroup, QuotaRequestContext ctx, long numTokens) { |
| // No-op |
| } |
| } |
| ---- |
| |
| [source, java] |
| ---- |
| import com.google.server.quota.QuotaEnforcer; |
| |
| class ApiQpsEnforcer implements QuotaEnforcer { |
| // AutoRefillingPerUserBuckets is a imaginary bucket implementation that could be based on |
| // a loading cache or a commonly used bucketing algorithm. |
| private final AutoRefillingPerUserBuckets<CurrentUser, Long> buckets; |
| @Override |
| QuotaResponse requestTokens(String quotaGroup, QuotaRequestContext ctx, long numTokens) { |
| if (!quotaGroup.startsWith("/restapi/")) { |
| return QuotaResponse.noOp(); |
| } |
| boolean success = buckets.deduct(ctx.user(), numTokens); |
| if (!success) { |
| return QuotaResponse.error("user sent too many qps, please wait for 5 minutes"); |
| } |
| return QuotaResponse.ok(); |
| } |
| |
| @Override |
| QuotaResponse dryRun(String quotaGroup, QuotaRequestContext ctx, long numTokens) { |
| if (!quotaGroup.startsWith("/restapi/")) { |
| return QuotaResponse.noOp(); |
| } |
| boolean success = buckets.checkOnly(ctx.user(), numTokens); |
| if (!success) { |
| return QuotaResponse.error("user sent too many qps, please wait for 5 minutes"); |
| } |
| return QuotaResponse.ok(); |
| } |
| |
| @Override |
| void refill(String quotaGroup, QuotaRequestContext ctx, long numTokens) { |
| if (!quotaGroup.startsWith("/restapi/")) { |
| return; |
| } |
| buckets.add(ctx.user(), numTokens); |
| } |
| } |
| ---- |
| |
| [[performance-logger]] |
| == Performance Logger |
| |
| `com.google.gerrit.server.logging.PerformanceLogger` is an extension point that |
| is invoked for all operations for which the execution time is measured. The |
| invocation of the extension point does not happen immediately, but only at the |
| end of a request (REST call, SSH call, git push). Implementors can write the |
| execution times into a performance log for further analysis. |
| |
| [[request-listener]] |
| == Request Listener |
| |
| `com.google.gerrit.server.RequestListener` is an extension point that is |
| invoked each time the server executes a request from a user. |
| |
| == SEE ALSO |
| |
| * link:js-api.html[JavaScript API] |
| * link:dev-rest-api.html[REST API Developers' Notes] |
| |
| GERRIT |
| ------ |
| Part of link:index.html[Gerrit Code Review] |
| |
| SEARCHBOX |
| --------- |