Merge branch 'stable-3.6' into stable-3.7

* stable-3.6:
  Set project and Gerrit version to v3.5.6
  Remove Maven legacy pom.xml
  Make events-broker a Gerrit plugin
  Provide subscribers with consumer's group id
  Remove actual implementation of InProcessBrokerApi
  Set event-broker and gerrit version to v3.4.8
  Add interface ExtendedBrokerApi to consume messages with groupId
  Change the build result name to events-broker.jar
  Set version to 3.6.3

Change-Id: I559ee13c4c2b57aded856e6763b1e68557c8ef43
tree: 7c45ec68ae2c07923e4d76f968717ab306a65906
  1. src/
  2. .gitignore
  3. BUILD
  4. Jenkinsfile
  5. LICENSE
  6. README.md
README.md

Events Broker API for Gerrit Code Review

API of a generic events broker for use with Gerrit Code Review.

Enables the de-coupling between Gerrit, plugins and the different implementations of a generic events broker.

Stream Events Publisher

It is a quite common use case for consumers of this library to listen for Gerrit events and to stream them on a specific topic.

Since the implementation of such logic is always the same, this library provides a generic stream events publisher which will perform the relevant operations.

In order to listen and stream gerrit events, consumers of this API need to provide a binding for the StreamEventPublisherConfig configuration and java.util.concurrent.Executor binding annotated with StreamEventPublisherExecutor annotation. A default single threaded implementation (StreamEventPublisherExecutor) is provided by the library. The last step is to explicitly bind the Stream Events Publisher, as such:

import com.gerritforge.gerrit.eventbroker.publisher.StreamEventPublisher;
import com.google.gerrit.extensions.registration.DynamicSet;
import com.google.gerrit.server.events.EventListener;
import com.google.inject.AbstractModule;

public class SomeModule extends AbstractModule {
    @Override
    protected void configure() {
        long messagePublishingTimeout = 1000L;

        bind(StreamEventPublisherConfig.class)
                .toInstance(new StreamEventPublisherConfig(
                    "name_of_the_stream_events_topic",
                    messagePublishingTimeout));
        
        bind(Executor.class).annotatedWith(StreamEventPublisherExecutor.class).toProvider(StreamEventPublisherExecutorProvider.class);
        DynamicSet.bind(binder(), EventListener.class).to(StreamEventPublisher.class);
    }
}

Alternative way to setup Stream Event Publisher is to use default Guice module:


import com.gerritforge.gerrit.eventbroker.publisher.StreamEventPublisherModule; import com.google.inject.AbstractModule; import com.google.inject.TypeLiteral; import com.google.inject.name.Names; public class SomeModule extends AbstractModule { @Override protected void configure() { long messagePublishingTimeout = 1000L; bind(StreamEventPublisherConfig.class) .toInstance(new StreamEventPublisherConfig( "name_of_the_stream_events_topic", messagePublishingTimeout)); install(new StreamEventPublisherModule()); } }

Note: To avoid message duplication Stream Events Publisher uses gerrit.instanceId and Event.instanceId to filter out forwarded events.

Broker Metrics

When StreamEventPublisher is used user can optionally bind an implementation of the BrokerMetrics` interface. This will allow to collect metrics about successful/failure stream events publishing. If no binding is provided default implementation will skip collecting metrics:

import com.google.gerrit.extensions.registration.DynamicItem;
import com.google.inject.AbstractModule;

public class SomeModule extends AbstractModule {
    @Override
    protected void configure() {
        DynamicItem.bind(binder(), BrokerMetrics.class)
            .to(BrokerMetricsImpl.class)
            .in(Scopes.SINGLETON);
    }
}

Note: BrokerMetrics implementation must be bound in a plugin module.