Revert "Remove publishing of stream events"

Revert "Remove publishing of stream events"

Revert submission 312871-centralize-stream-events-handling

Reason for revert: It broke existing functionality of events-* plugins
Reverted Changes:
I79a059deb:Remove publishing of stream events
I68906e9b4:Remove publishing of stream events
I632f7b900:Remove publishing of stream events
Iafe5a8155:Leverage stream events publishing from the events-...

Change-Id: Iccbfa651600c89e30705fe16d7149e04a7be9ec0
diff --git a/src/main/java/com/googlesource/gerrit/plugins/pubsub/Manager.java b/src/main/java/com/googlesource/gerrit/plugins/pubsub/Manager.java
index 1d5f649..01bd857 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/pubsub/Manager.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/pubsub/Manager.java
@@ -26,11 +26,16 @@
 
   private final Set<TopicSubscriber> consumers;
   private final BrokerApi brokerApi;
+  private final PubSubEventListener pubSubEventListener;
 
   @Inject
-  public Manager(Set<TopicSubscriber> consumers, BrokerApi brokerApi) {
+  public Manager(
+      Set<TopicSubscriber> consumers,
+      BrokerApi brokerApi,
+      PubSubEventListener pubSubEventListener) {
     this.consumers = consumers;
     this.brokerApi = brokerApi;
+    this.pubSubEventListener = pubSubEventListener;
   }
 
   @Override
@@ -43,5 +48,6 @@
   @Override
   public void stop() {
     brokerApi.disconnect();
+    pubSubEventListener.disconnect();
   }
 }
diff --git a/src/main/java/com/googlesource/gerrit/plugins/pubsub/Module.java b/src/main/java/com/googlesource/gerrit/plugins/pubsub/Module.java
index d1723c7..50fad61 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/pubsub/Module.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/pubsub/Module.java
@@ -18,6 +18,7 @@
 import com.google.gerrit.extensions.config.FactoryModule;
 import com.google.gerrit.extensions.events.LifecycleListener;
 import com.google.gerrit.extensions.registration.DynamicSet;
+import com.google.gerrit.server.events.EventListener;
 import com.google.inject.Inject;
 import com.google.inject.Scopes;
 import com.googlesource.gerrit.plugins.pubsub.local.EnvironmentChecker;
@@ -39,6 +40,7 @@
   @Override
   protected void configure() {
     DynamicSet.bind(binder(), LifecycleListener.class).to(Manager.class);
+    DynamicSet.bind(binder(), EventListener.class).to(PubSubEventListener.class);
     factory(PubSubPublisher.Factory.class);
     factory(PubSubEventSubscriber.Factory.class);
 
diff --git a/src/main/java/com/googlesource/gerrit/plugins/pubsub/PubSubConfiguration.java b/src/main/java/com/googlesource/gerrit/plugins/pubsub/PubSubConfiguration.java
index 465c913..614d0aa 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/pubsub/PubSubConfiguration.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/pubsub/PubSubConfiguration.java
@@ -28,6 +28,7 @@
   private static final String DEFAULT_ACK_DEADLINE_SECONDS = "10";
   private static final String DEFAULT_SUBSCTIPRION_TIMEOUT = "10";
   private static final String DEFAULT_SHUTDOWN_TIMEOUT = "10";
+  private static final String DEFAULT_STREAM_EVENTS_TOPIC = "gerrit";
 
   private final String gcloudProject;
   private final String subscriptionId;
@@ -36,6 +37,7 @@
   private final Integer ackDeadlineSeconds;
   private final Long subscribtionTimeoutInSeconds;
   private final Long shutdownTimeoutInSeconds;
+  private final String streamEventsTopic;
   private final PluginConfig fromGerritConfig;
 
   @Inject
@@ -47,6 +49,8 @@
     this.gcloudProject = getMandatoryString("gcloudProject");
     this.subscriptionId = getMandatoryString("subscriptionId", instanceId);
     this.privateKeyLocation = getMandatoryString("privateKeyLocation");
+    this.streamEventsTopic =
+        fromGerritConfig.getString("streamEventsTopic", DEFAULT_STREAM_EVENTS_TOPIC);
     this.numberOfSubscribers =
         Integer.parseInt(
             fromGerritConfig.getString("numberOfSubscribers", DEFAULT_NUMBER_OF_SUBSCRIBERS));
@@ -90,6 +94,10 @@
     return shutdownTimeoutInSeconds;
   }
 
+  public String getStreamEventsTopic() {
+    return streamEventsTopic;
+  }
+
   private String getMandatoryString(String name) throws IllegalStateException {
     return getMandatoryString(name, null);
   }
diff --git a/src/main/java/com/googlesource/gerrit/plugins/pubsub/PubSubEventListener.java b/src/main/java/com/googlesource/gerrit/plugins/pubsub/PubSubEventListener.java
new file mode 100644
index 0000000..29ec263
--- /dev/null
+++ b/src/main/java/com/googlesource/gerrit/plugins/pubsub/PubSubEventListener.java
@@ -0,0 +1,46 @@
+// Copyright (C) 2021 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+package com.googlesource.gerrit.plugins.pubsub;
+
+import com.google.common.flogger.FluentLogger;
+import com.google.gerrit.server.events.Event;
+import com.google.gerrit.server.events.EventListener;
+import com.google.inject.Inject;
+import com.google.inject.Singleton;
+
+@Singleton
+public class PubSubEventListener implements EventListener {
+  private static final FluentLogger logger = FluentLogger.forEnclosingClass();
+
+  private final PubSubPublisher publisher;
+
+  @Inject
+  public PubSubEventListener(
+      PubSubPublisher.Factory publisherFactory, PubSubConfiguration configuration) {
+    this.publisher = publisherFactory.create(configuration.getStreamEventsTopic());
+  }
+
+  @Override
+  public void onEvent(Event event) {
+    publisher.publish(event);
+  }
+
+  public void disconnect() {
+    try {
+      publisher.close();
+    } catch (InterruptedException e) {
+      logger.atSevere().withCause(e).log("Disconnect failed");
+    }
+  }
+}
diff --git a/src/main/resources/Documentation/config.md b/src/main/resources/Documentation/config.md
index d5f9643..f3263d3 100644
--- a/src/main/resources/Documentation/config.md
+++ b/src/main/resources/Documentation/config.md
@@ -42,3 +42,8 @@
 `plugin.events-gcloud-pubsub.subscribtionTimeoutInSeconds`
 :   Optional. Maximum time in seconds to wait for the subscriber to connect to GCloud PubSub topic.
     Default: 10
+
+`plugin.events-gcloud-pubsub.streamEventsTopic`
+:   Optional. Name of the GCloud PubSub topic for stream events. events-gcloud-pubsub plugin exposes
+    all stream events under this topic name.
+    Default: gerrit
diff --git a/src/test/java/com/googlesource/gerrit/plugins/pubsub/PubSubBrokerApiIT.java b/src/test/java/com/googlesource/gerrit/plugins/pubsub/PubSubBrokerApiIT.java
index 4a68b8b..d202f25 100644
--- a/src/test/java/com/googlesource/gerrit/plugins/pubsub/PubSubBrokerApiIT.java
+++ b/src/test/java/com/googlesource/gerrit/plugins/pubsub/PubSubBrokerApiIT.java
@@ -15,6 +15,8 @@
 package com.googlesource.gerrit.plugins.pubsub;
 
 import static com.google.common.truth.Truth.assertThat;
+import static java.util.stream.Collectors.counting;
+import static java.util.stream.Collectors.groupingBy;
 
 import com.gerritforge.gerrit.eventbroker.BrokerApi;
 import com.google.api.gax.core.NoCredentialsProvider;
@@ -36,18 +38,22 @@
 import com.google.gerrit.server.events.Event;
 import com.google.gerrit.server.events.EventGson;
 import com.google.gerrit.server.events.ProjectCreatedEvent;
+import com.google.gerrit.server.events.RefUpdatedEvent;
 import com.google.gson.Gson;
 import com.google.inject.Inject;
 import com.google.pubsub.v1.ProjectSubscriptionName;
 import com.google.pubsub.v1.PullRequest;
 import com.google.pubsub.v1.PullResponse;
 import com.google.pubsub.v1.PushConfig;
+import com.google.pubsub.v1.ReceivedMessage;
 import com.google.pubsub.v1.TopicName;
 import com.googlesource.gerrit.plugins.pubsub.local.EnvironmentChecker;
 import io.grpc.ManagedChannel;
 import io.grpc.ManagedChannelBuilder;
 import java.io.IOException;
 import java.time.Duration;
+import java.util.List;
+import java.util.Map;
 import java.util.function.Consumer;
 import org.junit.Test;
 import org.testcontainers.containers.PubSubEmulatorContainer;
@@ -129,6 +135,36 @@
   @GerritConfig(
       name = "plugin.events-gcloud-pubsub.privateKeyLocation",
       value = PRIVATE_KEY_LOCATION)
+  public void shouldProduceStreamEvents() throws Exception {
+    String subscriptionId = "gerrit-subscription-id";
+    String topicId = "gerrit";
+    createSubscription(subscriptionId, topicId, channelProvider, credentialsProvider);
+
+    createChange();
+
+    readMessageAndValidate(
+        (pullResponse) -> {
+          List<ReceivedMessage> messages = pullResponse.getReceivedMessagesList();
+          assertThat(messages).hasSize(4);
+          Map<String, Long> messageTypeCount =
+              messages.stream()
+                  .map(m -> gson.fromJson(m.getMessage().getData().toStringUtf8(), Map.class))
+                  .map(m -> m.get("type").toString())
+                  .collect(groupingBy(t -> t, counting()));
+
+          assertThat(messageTypeCount.get(RefUpdatedEvent.TYPE)).isEqualTo(3);
+          assertThat(messageTypeCount.get("patchset-created")).isEqualTo(1);
+        },
+        PROJECT_ID,
+        subscriptionId);
+  }
+
+  @Test
+  @GerritConfig(name = "plugin.events-gcloud-pubsub.gcloudProject", value = PROJECT_ID)
+  @GerritConfig(name = "plugin.events-gcloud-pubsub.subscriptionId", value = SUBSCRIPTION_ID)
+  @GerritConfig(
+      name = "plugin.events-gcloud-pubsub.privateKeyLocation",
+      value = PRIVATE_KEY_LOCATION)
   public void shouldConsumeEvent() throws InterruptedException {
     Event event = new ProjectCreatedEvent();
     event.instanceId = DEFAULT_INSTANCE_ID;