Instrument Gradle build with metrics.

buildSrc/build.gradle

@@ -38,6 +38,10 @@ dependencies {
     implementation "com.jaredsburrows:gradle-license-plugin:0.8.1"
     implementation 'digital.wup:android-maven-publish:3.6.2'
 
+    implementation 'io.opencensus:opencensus-api:0.18.0'
+    implementation 'io.opencensus:opencensus-exporter-stats-stackdriver:0.18.0'
+    runtime 'io.opencensus:opencensus-impl:0.18.0'
+
     implementation 'com.android.tools.build:gradle:3.2.1'
     testImplementation 'junit:junit:4.12'
     testImplementation 'org.json:json:20180813'

buildSrc/src/main/groovy/com/google/firebase/gradle/plugins/ci/metrics/DrainingBuildListener.java

@@ -0,0 +1,53 @@
+// Copyright 2018 Google LLC
+//
+// 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.google.firebase.gradle.plugins.ci.metrics;
+
+import org.gradle.BuildAdapter;
+import org.gradle.BuildResult;
+import org.gradle.api.logging.Logger;
+
+/**
+ * Build listener that waits for Stackdriver to export metrics before exiting.
+ *
+ * <p>Stackdriver exporter is implemented in such a way that it exports metrics on a periodic basis,
+ * with period being configurable. This means that, when the build finishes and exits, it is highly
+ * likely that there are unexported metrics in memory. For this reason we have this build listener
+ * that makes the gradle process sleep for the duration of the configured export period to make sure
+ * metrics get exported.
+ *
+ * @see <a
+ *     href="https://opencensus.io/exporters/supported-exporters/java/stackdriver-stats/">Opencensus
+ *     docs</a>
+ */
+class DrainingBuildListener extends BuildAdapter {
+  private final long sleepDuration;
+  private final Logger logger;
+
+  DrainingBuildListener(long sleepDuration, Logger logger) {
+    this.sleepDuration = sleepDuration;
+    this.logger = logger;
+  }
+
+  @Override
+  public void buildFinished(BuildResult result) {
+    try {
+      logger.lifecycle("Draining metrics to Stackdriver.");
+      Thread.sleep(sleepDuration);
+    } catch (InterruptedException e) {
+      // Restore the interrupted status
+      Thread.currentThread().interrupt();
+    }
+  }
+}

buildSrc/src/main/groovy/com/google/firebase/gradle/plugins/ci/metrics/MeasuringTaskExecutionListener.java

@@ -0,0 +1,92 @@
+// Copyright 2018 Google LLC
+//
+// 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.google.firebase.gradle.plugins.ci.metrics;
+
+import java.util.ArrayDeque;
+import java.util.HashSet;
+import java.util.Queue;
+import java.util.Set;
+import org.gradle.api.Task;
+import org.gradle.api.execution.TaskExecutionGraph;
+import org.gradle.api.execution.TaskExecutionListener;
+import org.gradle.api.tasks.TaskState;
+
+class MeasuringTaskExecutionListener implements TaskExecutionListener {
+  private static final String METRICS_START_TIME = "metricsStartTime";
+  private static final String METRICS_ELAPSED_TIME = "metricsElapsedTime";
+
+  private final Metrics metrics;
+  private final TaskExecutionGraph taskGraph;
+
+  MeasuringTaskExecutionListener(Metrics metrics, TaskExecutionGraph taskGraph) {
+    this.metrics = metrics;
+    this.taskGraph = taskGraph;
+  }
+
+  @Override
+  public void beforeExecute(Task task) {
+    recordStart(task);
+  }
+
+  @Override
+  public void afterExecute(Task task, TaskState taskState) {
+    recordElapsed(task);
+    long elapsedTime = getTotalElapsed(task);
+
+    if (taskState.getFailure() != null) {
+      metrics.measureFailure(task);
+      return;
+    }
+    metrics.measureSuccess(task, elapsedTime);
+  }
+
+  private static void recordStart(Task task) {
+    task.getExtensions().add(METRICS_START_TIME, System.currentTimeMillis());
+  }
+
+  private static void recordElapsed(Task task) {
+    long startTime = (long) task.getExtensions().getByName(METRICS_START_TIME);
+    task.getExtensions().add(METRICS_ELAPSED_TIME, System.currentTimeMillis() - startTime);
+  }
+
+  private static long getElapsed(Task task) {
+    return (long) task.getExtensions().getByName(METRICS_ELAPSED_TIME);
+  }
+
+  // a tasks elapsed time does not include how long it took for its dependencies took to execute,
+  // so we walk the dependency graph to get the total elapsed time.
+  private long getTotalElapsed(Task task) {
+    Queue<Task> queue = new ArrayDeque<>();
+    queue.add(task);
+    Set<Task> visited = new HashSet<>();
+
+    long totalElapsed = 0;
+    while (!queue.isEmpty()) {
+      Task currentTask = queue.remove();
+      if (!visited.add(currentTask)) {
+        continue;
+      }
+
+      totalElapsed += getElapsed(currentTask);
+
+      for (Task dep : taskGraph.getDependencies(currentTask)) {
+        if (!visited.contains(dep)) {
+          queue.add(dep);
+        }
+      }
+    }
+    return totalElapsed;
+  }
+}

buildSrc/src/main/groovy/com/google/firebase/gradle/plugins/ci/metrics/Metrics.java

@@ -0,0 +1,26 @@
+// Copyright 2018 Google LLC
+//
+// 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.google.firebase.gradle.plugins.ci.metrics;
+
+import org.gradle.api.Task;
+
+/** Provides methods for measuring various parts of the build. */
+interface Metrics {
+  /** Measure successful execution of a task. */
+  void measureSuccess(Task task, long elapsedTime);
+
+  /** Measure task execution failure. */
+  void measureFailure(Task task);
+}

buildSrc/src/main/groovy/com/google/firebase/gradle/plugins/ci/metrics/MetricsPlugin.java

@@ -0,0 +1,41 @@
+// Copyright 2018 Google LLC
+//
+// 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.google.firebase.gradle.plugins.ci.metrics;
+
+import org.gradle.api.Plugin;
+import org.gradle.api.Project;
+import org.gradle.api.execution.TaskExecutionGraph;
+
+/** Instruments Gradle to measure latency and success rate of all executed tasks. */
+public class MetricsPlugin implements Plugin<Project> {
+  @Override
+  public void apply(Project project) {
+    if (!isCollectionEnabled()) {
+      project.getLogger().lifecycle("Metrics collection is disabled.");
+      return;
+    }
+    project.getLogger().lifecycle("Metrics collection is enabled.");
+
+    Metrics metrics = new StackdriverMetrics(project.getGradle(), project.getLogger());
+
+    TaskExecutionGraph taskGraph = project.getGradle().getTaskGraph();
+    taskGraph.addTaskExecutionListener(new MeasuringTaskExecutionListener(metrics, taskGraph));
+  }
+
+  private static boolean isCollectionEnabled() {
+    String enabled = System.getenv("FIREBASE_ENABLE_METRICS");
+    return enabled != null && enabled.equals("1");
+  }
+}

buildSrc/src/main/groovy/com/google/firebase/gradle/plugins/ci/metrics/StackdriverMetrics.java

@@ -0,0 +1,159 @@
+// Copyright 2018 Google LLC
+//
+// 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.google.firebase.gradle.plugins.ci.metrics;
+
+import io.opencensus.common.Duration;
+import io.opencensus.exporter.stats.stackdriver.StackdriverStatsConfiguration;
+import io.opencensus.exporter.stats.stackdriver.StackdriverStatsExporter;
+import io.opencensus.stats.Aggregation;
+import io.opencensus.stats.Measure;
+import io.opencensus.stats.Stats;
+import io.opencensus.stats.View;
+import io.opencensus.tags.TagContext;
+import io.opencensus.tags.TagKey;
+import io.opencensus.tags.TagValue;
+import io.opencensus.tags.Tags;
+import io.opencensus.tags.propagation.TagContextBinarySerializer;
+import io.opencensus.tags.propagation.TagContextDeserializationException;
+import java.io.IOException;
+import java.util.Arrays;
+import java.util.Base64;
+import java.util.List;
+import java.util.concurrent.atomic.AtomicBoolean;
+import org.gradle.api.GradleException;
+import org.gradle.api.Task;
+import org.gradle.api.invocation.Gradle;
+import org.gradle.api.logging.Logger;
+
+/**
+ * Object used to record measurements via {@link #measureSuccess(Task, long)} and {@link
+ * #measureFailure(Task)}.
+ */
+class StackdriverMetrics implements Metrics {
+  private static final AtomicBoolean STACKDRIVER_INITIALIZED = new AtomicBoolean();
+  private static final long STACKDRIVER_UPLOAD_PERIOD_MS = 5000;
+
+  private final TagContext globalContext;
+  private final Logger logger;
+
+  private static Measure.MeasureDouble M_LATENCY =
+      Measure.MeasureDouble.create("latency", "", "ms");
+  private static Measure.MeasureLong M_SUCCESS = Measure.MeasureLong.create("success", "", "1");
+
+  private static final TagKey STAGE = TagKey.create("stage");
+  private static final TagKey GRADLE_PROJECT = TagKey.create("gradle_project");
+
+  private static final List<TagKey> TAG_KEYS =
+      Arrays.asList(
+          STAGE,
+          GRADLE_PROJECT,
+          TagKey.create("repo_owner"),
+          TagKey.create("repo_name"),
+          TagKey.create("pull_number"),
+          TagKey.create("job_name"),
+          TagKey.create("build_id"),
+          TagKey.create("job_type"));
+
+  StackdriverMetrics(Gradle gradle, Logger logger) {
+    this.logger = logger;
+    globalContext = deserializeContext();
+
+    ensureStackdriver(gradle);
+
+    Stats.getViewManager()
+        .registerView(
+            View.create(
+                View.Name.create("fireci/tasklatency"),
+                "The latency in milliseconds",
+                M_LATENCY,
+                Aggregation.LastValue.create(),
+                TAG_KEYS));
+
+    Stats.getViewManager()
+        .registerView(
+            View.create(
+                View.Name.create("fireci/tasksuccess"),
+                "Indicated success or failure.",
+                M_SUCCESS,
+                Aggregation.LastValue.create(),
+                TAG_KEYS));
+  }
+
+  /** Records failure of the execution stage named {@code name}. */
+  public void measureFailure(Task task) {
+
+    TagContext ctx =
+        Tags.getTagger()
+            .toBuilder(globalContext)
+            .put(STAGE, TagValue.create(task.getName()))
+            .put(GRADLE_PROJECT, TagValue.create(task.getProject().getPath()))
+            .build();
+    Stats.getStatsRecorder().newMeasureMap().put(M_SUCCESS, 0).record(ctx);
+  }
+
+  /** Records success and latency of the execution stage named {@code name}. */
+  public void measureSuccess(Task task, long elapsedTime) {
+
+    TagContext ctx =
+        Tags.getTagger()
+            .toBuilder(globalContext)
+            .put(STAGE, TagValue.create(task.getName()))
+            .put(GRADLE_PROJECT, TagValue.create(task.getProject().getPath()))
+            .build();
+    Stats.getStatsRecorder()
+        .newMeasureMap()
+        .put(M_SUCCESS, 1)
+        .put(M_LATENCY, elapsedTime)
+        .record(ctx);
+  }
+
+  private void ensureStackdriver(Gradle gradle) {
+    // make sure we only initialize stackdriver once as gradle daemon is not guaranteed to restart
+    // across gradle invocations.
+    if (!STACKDRIVER_INITIALIZED.compareAndSet(false, true)) {
+      logger.lifecycle("Stackdriver exporter already initialized.");
+      return;
+    }
+    logger.lifecycle("Initializing Stackdriver exporter.");
+
+    try {
+      StackdriverStatsExporter.createAndRegister(
+          StackdriverStatsConfiguration.builder()
+              .setExportInterval(Duration.fromMillis(STACKDRIVER_UPLOAD_PERIOD_MS))
+              .build());
+
+      // make sure gradle does not exit before metrics get uploaded to stackdriver.
+      gradle.addBuildListener(new DrainingBuildListener(STACKDRIVER_UPLOAD_PERIOD_MS, logger));
+    } catch (IOException e) {
+      throw new GradleException("Could not configure metrics exporter", e);
+    }
+  }
+
+  /** Extract opencensus context(if any) from environment. */
+  private static TagContext deserializeContext() {
+    String serializedContext = System.getenv("OPENCENSUS_STATS_CONTEXT");
+    if (serializedContext == null) {
+      return Tags.getTagger().empty();
+    }
+
+    TagContextBinarySerializer serializer = Tags.getTagPropagationComponent().getBinarySerializer();
+
+    try {
+      return serializer.fromByteArray(Base64.getDecoder().decode(serializedContext));
+    } catch (TagContextDeserializationException e) {
+      return Tags.getTagger().empty();
+    }
+  }
+}

ci/fireci/fireci/gradle.py

@@ -29,6 +29,7 @@ def P(name, value):
   return '-P{}={}'.format(name, value)
 
 
+@stats.measure_call('gradle')
 def run(*args, gradle_opts='', workdir=None):
   """Invokes gradle with specified args and gradle_opts."""
   new_env = dict(os.environ)