Move monitored resource detection utils to a separate artifact. (#1135)

Move monitored resource detection utils to a separate artifact, so that it can be reused by both Stackdriver Monitoring and Stackdriver Trace.

16 files changed, 624 insertions, 158 deletions

diff --git a/all/build.gradle b/all/build.gradle
index e8440728..044dc13f 100644
--- a/all/build.gradle
+++ b/all/build.gradle
@@ -16,6 +16,7 @@ def subprojects = [
         project(':opencensus-contrib-grpc-util'),
         project(':opencensus-contrib-grpc-metrics'),
         project(':opencensus-contrib-http-util'),
+        project(':opencensus-contrib-monitored-resource-util'),
         project(':opencensus-contrib-zpages'),
         project(':opencensus-exporter-trace-logging'),
         project(':opencensus-exporter-trace-stackdriver'),
@@ -34,6 +35,7 @@ def subprojects_javadoc = [
         project(':opencensus-contrib-grpc-util'),
         project(':opencensus-contrib-grpc-metrics'),
         project(':opencensus-contrib-http-util'),
+        project(':opencensus-contrib-monitored-resource-util'),
         project(':opencensus-contrib-zpages'),
         project(':opencensus-exporter-trace-logging'),
         project(':opencensus-exporter-trace-stackdriver'),
diff --git a/build.gradle b/build.gradle
index d36b571a..47b7502e 100644
--- a/build.gradle
+++ b/build.gradle
@@ -362,6 +362,7 @@ subprojects {
                  'opencensus-contrib-grpc-metrics',
                  'opencensus-contrib-grpc-util',
                  'opencensus-contrib-http-util',
+                 'opencensus-contrib-monitored-resource-util',
                  'opencensus-contrib-zpages',
                  'opencensus-exporter-stats-prometheus',
                  'opencensus-exporter-stats-signalfx',
diff --git a/buildscripts/import-control.xml b/buildscripts/import-control.xml
index 75ae826a..38cd747d 100644
--- a/buildscripts/import-control.xml
+++ b/buildscripts/import-control.xml
@@ -92,6 +92,9 @@ General guidelines on imports:
       <allow pkg="io.opencensus.tags"/>
       <allow pkg="io.opencensus.trace"/>
     </subpackage>
+    <subpackage name="monitoredresource.util">
+      <allow pkg="io.opencensus.contrib.monitoredresource.util"/>
+    </subpackage>
   </subpackage>
   <subpackage name="exporter">
     <allow pkg="com.google.common"/>
@@ -113,6 +116,7 @@ General guidelines on imports:
         <allow pkg="com.google"/>
         <allow pkg="io.opencensus.exporter.stats.stackdriver"/>
         <allow pkg="io.opencensus.trace"/>
+        <allow pkg="io.opencensus.contrib.monitoredresource.util"/>
       </subpackage>
     </subpackage>
     <subpackage name="trace">
diff --git a/contrib/monitored_resource_util/README.md b/contrib/monitored_resource_util/README.md
new file mode 100644
index 00000000..00b9feaf
--- /dev/null
+++ b/contrib/monitored_resource_util/README.md
@@ -0,0 +1,34 @@
+# OpenCensus Monitored Resources Util
+[![Build Status][travis-image]][travis-url]
+[![Windows Build Status][appveyor-image]][appveyor-url]
+[![Maven Central][maven-image]][maven-url]
+
+The *OpenCensus Monitored Resource Util for Java* is a collection of utilities for auto detecting
+monitored resource when exporting stats, based on the environment where the application is running.
+
+## Quickstart
+
+### Add the dependencies to your project
+
+For Maven add to your `pom.xml`:
+```xml
+<dependencies>
+  <dependency>
+    <groupId>io.opencensus</groupId>
+    <artifactId>opencensus-contrib-monitored-resource-util</artifactId>
+    <version>0.13.0</version>
+  </dependency>
+</dependencies>
+```
+
+For Gradle add to your dependencies:
+```gradle
+compile 'io.opencensus:opencensus-contrib-monitored-resource-util:0.13.0'
+```
+
+[travis-image]: https://travis-ci.org/census-instrumentation/opencensus-java.svg?branch=master
+[travis-url]: https://travis-ci.org/census-instrumentation/opencensus-java
+[appveyor-image]: https://ci.appveyor.com/api/projects/status/hxthmpkxar4jq4be/branch/master?svg=true
+[appveyor-url]: https://ci.appveyor.com/project/opencensusjavateam/opencensus-java/branch/master
+[maven-image]: https://maven-badges.herokuapp.com/maven-central/io.opencensus/opencensus-contrib-monitoredresource-util/badge.svg
+[maven-url]: https://maven-badges.herokuapp.com/maven-central/io.opencensus/opencensus-contrib-monitoredresource-util
diff --git a/contrib/monitored_resource_util/build.gradle b/contrib/monitored_resource_util/build.gradle
new file mode 100644
index 00000000..141ff7fc
--- /dev/null
+++ b/contrib/monitored_resource_util/build.gradle
@@ -0,0 +1,14 @@
+description = 'OpenCensus Monitored Resource Util'
+
+apply plugin: 'java'
+
+[compileJava, compileTestJava].each() {
+    it.sourceCompatibility = 1.6
+    it.targetCompatibility = 1.6
+}
+
+dependencies {
+    compileOnly libraries.auto_value
+
+    signature "org.codehaus.mojo.signature:java16:+@signature"
+}
diff --git a/exporters/stats/stackdriver/src/main/java/io/opencensus/exporter/stats/stackdriver/AwsIdentityDocUtils.java b/contrib/monitored_resource_util/src/main/java/io/opencensus/contrib/monitoredresource/util/AwsIdentityDocUtils.java
index fbbdf80b..03b0bd4d 100644
--- a/exporters/stats/stackdriver/src/main/java/io/opencensus/exporter/stats/stackdriver/AwsIdentityDocUtils.java
+++ b/contrib/monitored_resource_util/src/main/java/io/opencensus/contrib/monitoredresource/util/AwsIdentityDocUtils.java
@@ -14,12 +14,8 @@
  * limitations under the License.
  */
 
-package io.opencensus.exporter.stats.stackdriver;
+package io.opencensus.contrib.monitoredresource.util;
 
-import com.google.common.annotations.VisibleForTesting;
-import com.google.common.base.Charsets;
-import com.google.common.base.Splitter;
-import com.google.common.collect.Maps;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.InputStreamReader;
@@ -27,7 +23,8 @@ import java.io.Reader;
 import java.net.HttpURLConnection;
 import java.net.URI;
 import java.nio.CharBuffer;
-import java.util.List;
+import java.nio.charset.Charset;
+import java.util.HashMap;
 import java.util.Map;
 import javax.annotation.concurrent.GuardedBy;
 
@@ -36,11 +33,10 @@ final class AwsIdentityDocUtils {
 
   private static final Object monitor = new Object();
   private static final int AWS_IDENTITY_DOC_BUF_SIZE = 0x800; // 2K chars (4K bytes)
-  private static final Splitter AWS_IDENTITY_DOC_LINE_BREAK_SPLITTER = Splitter.on('\n');
-  private static final Splitter AWS_IDENTITY_DOC_COLON_SPLITTER = Splitter.on(':');
+  private static final String AWS_IDENTITY_DOC_LINE_BREAK_SPLITTER = "\n";
+  private static final String AWS_IDENTITY_DOC_COLON_SPLITTER = ":";
 
-  @VisibleForTesting
-  static final URI AWS_INSTANCE_IDENTITY_DOCUMENT_URI =
+  private static final URI AWS_INSTANCE_IDENTITY_DOCUMENT_URI =
       URI.create("http://169.254.169.254/latest/dynamic/instance-identity/document");
 
   @GuardedBy("monitor")
@@ -67,7 +63,7 @@ final class AwsIdentityDocUtils {
     InputStream stream = null;
     try {
       stream = openStream(AWS_INSTANCE_IDENTITY_DOCUMENT_URI);
-      String awsIdentityDocument = slurp(new InputStreamReader(stream, Charsets.UTF_8));
+      String awsIdentityDocument = slurp(new InputStreamReader(stream, Charset.forName("UTF-8")));
       synchronized (monitor) {
         awsEnvVarMap = parseAwsIdentityDocument(awsIdentityDocument);
       }
@@ -110,17 +106,18 @@ final class AwsIdentityDocUtils {
 
   // AWS Instance Identity Document is a JSON file.
   // See docs.aws.amazon.com/AWSEC2/latest/UserGuide/instance-identity-documents.html.
-  @VisibleForTesting
   static Map<String, String> parseAwsIdentityDocument(String awsIdentityDocument) {
-    Map<String, String> map = Maps.newHashMap();
-    List<String> lines = AWS_IDENTITY_DOC_LINE_BREAK_SPLITTER.splitToList(awsIdentityDocument);
+    Map<String, String> map = new HashMap<String, String>();
+    @SuppressWarnings("StringSplitter")
+    String[] lines = awsIdentityDocument.split(AWS_IDENTITY_DOC_LINE_BREAK_SPLITTER, -1);
     for (String line : lines) {
-      List<String> keyValuePair = AWS_IDENTITY_DOC_COLON_SPLITTER.splitToList(line);
-      if (keyValuePair.size() != 2) {
+      @SuppressWarnings("StringSplitter")
+      String[] keyValuePair = line.split(AWS_IDENTITY_DOC_COLON_SPLITTER, -1);
+      if (keyValuePair.length != 2) {
         continue;
       }
-      String key = keyValuePair.get(0).replaceAll("[\" ]", "");
-      String value = keyValuePair.get(1).replaceAll("[\" ,]", "");
+      String key = keyValuePair[0].replaceAll("[\" ]", "");
+      String value = keyValuePair[1].replaceAll("[\" ,]", "");
       map.put(key, value);
     }
     return map;
diff --git a/contrib/monitored_resource_util/src/main/java/io/opencensus/contrib/monitoredresource/util/GcpMetadataConfig.java b/contrib/monitored_resource_util/src/main/java/io/opencensus/contrib/monitoredresource/util/GcpMetadataConfig.java
new file mode 100644
index 00000000..c09d1c65
--- /dev/null
+++ b/contrib/monitored_resource_util/src/main/java/io/opencensus/contrib/monitoredresource/util/GcpMetadataConfig.java
@@ -0,0 +1,90 @@
+/*
+ * Copyright 2018, OpenCensus Authors
+ *
+ * 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 io.opencensus.contrib.monitoredresource.util;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.net.HttpURLConnection;
+import java.net.URL;
+import java.nio.charset.Charset;
+import javax.annotation.Nullable;
+
+/**
+ * Retrieves Google Cloud project-id and a limited set of instance attributes from Metadata server.
+ *
+ * @see <a href="https://cloud.google.com/compute/docs/storing-retrieving-metadata">
+ *     https://cloud.google.com/compute/docs/storing-retrieving-metadata</a>
+ */
+final class GcpMetadataConfig {
+
+  private static final String METADATA_URL = "http://metadata/computeMetadata/v1/";
+
+  private GcpMetadataConfig() {}
+
+  @Nullable
+  static String getProjectId() {
+    return getAttribute("project/project-id");
+  }
+
+  @Nullable
+  static String getZone() {
+    String zoneId = getAttribute("instance/zone");
+    if (zoneId == null) {
+      return null;
+    }
+    if (zoneId.contains("/")) {
+      return zoneId.substring(zoneId.lastIndexOf('/') + 1);
+    }
+    return zoneId;
+  }
+
+  @Nullable
+  static String getInstanceId() {
+    return getAttribute("instance/id");
+  }
+
+  @Nullable
+  static String getClusterName() {
+    return getAttribute("instance/attributes/cluster-name");
+  }
+
+  @Nullable
+  private static String getAttribute(String attributeName) {
+    try {
+      URL url = new URL(METADATA_URL + attributeName);
+      HttpURLConnection connection = (HttpURLConnection) url.openConnection();
+      connection.setRequestProperty("Metadata-Flavor", "Google");
+      InputStream input = connection.getInputStream();
+      if (connection.getResponseCode() == 200) {
+        BufferedReader reader = null;
+        try {
+          reader = new BufferedReader(new InputStreamReader(input, Charset.forName("UTF-8")));
+          return reader.readLine();
+        } finally {
+          if (reader != null) {
+            reader.close();
+          }
+        }
+      }
+    } catch (IOException ignore) {
+      // ignore
+    }
+    return null;
+  }
+}
diff --git a/contrib/monitored_resource_util/src/main/java/io/opencensus/contrib/monitoredresource/util/MonitoredResource.java b/contrib/monitored_resource_util/src/main/java/io/opencensus/contrib/monitoredresource/util/MonitoredResource.java
new file mode 100644
index 00000000..c7e91117
--- /dev/null
+++ b/contrib/monitored_resource_util/src/main/java/io/opencensus/contrib/monitoredresource/util/MonitoredResource.java
@@ -0,0 +1,252 @@
+/*
+ * Copyright 2018, OpenCensus Authors
+ *
+ * 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 io.opencensus.contrib.monitoredresource.util;
+
+import com.google.auto.value.AutoValue;
+import javax.annotation.Nullable;
+import javax.annotation.concurrent.Immutable;
+
+/**
+ * {@link MonitoredResource} represents an auto-detected monitored resource used by application for
+ * exporting stats. It has a {@code ResourceType} associated with a mapping from resource labels to
+ * values.
+ *
+ * @since 0.13
+ */
+@Immutable
+public abstract class MonitoredResource {
+
+  MonitoredResource() {}
+
+  /**
+   * Returns the {@link ResourceType} of this {@link MonitoredResource}.
+   *
+   * @return the {@code ResourceType}.
+   * @since 0.13
+   */
+  public abstract ResourceType getResourceType();
+
+  /*
+   * Returns the first of two given parameters that is not null, if either is, or otherwise
+   * throws a NullPointerException.
+   */
+  private static <T> T firstNonNull(@Nullable T first, @Nullable T second) {
+    if (first != null) {
+      return first;
+    }
+    if (second != null) {
+      return second;
+    }
+    throw new NullPointerException("Both parameters are null");
+  }
+
+  // TODO(songya): consider using a tagged union match() approach (that will introduce
+  // dependency on opencensus-api).
+
+  /**
+   * {@link MonitoredResource} for AWS EC2 instance.
+   *
+   * @since 0.13
+   */
+  @Immutable
+  @AutoValue
+  public abstract static class AwsEc2InstanceMonitoredResource extends MonitoredResource {
+
+    private static final String AWS_ACCOUNT =
+        firstNonNull(AwsIdentityDocUtils.getValueFromAwsIdentityDocument("accountId"), "");
+    private static final String AWS_INSTANCE_ID =
+        firstNonNull(AwsIdentityDocUtils.getValueFromAwsIdentityDocument("instanceId"), "");
+    private static final String AWS_REGION =
+        firstNonNull(AwsIdentityDocUtils.getValueFromAwsIdentityDocument("region"), "");
+
+    @Override
+    public ResourceType getResourceType() {
+      return ResourceType.AWS_EC2_INSTANCE;
+    }
+
+    /**
+     * Returns the AWS account ID.
+     *
+     * @return the AWS account ID.
+     * @since 0.13
+     */
+    public abstract String getAccount();
+
+    /**
+     * Returns the AWS EC2 instance ID.
+     *
+     * @return the AWS EC2 instance ID.
+     * @since 0.13
+     */
+    public abstract String getInstanceId();
+
+    /**
+     * Returns the AWS region.
+     *
+     * @return the AWS region.
+     * @since 0.13
+     */
+    public abstract String getRegion();
+
+    static AwsEc2InstanceMonitoredResource create() {
+      return new AutoValue_MonitoredResource_AwsEc2InstanceMonitoredResource(
+          AWS_ACCOUNT, AWS_INSTANCE_ID, AWS_REGION);
+    }
+  }
+
+  /**
+   * {@link MonitoredResource} for GCP GCE instance.
+   *
+   * @since 0.13
+   */
+  @Immutable
+  @AutoValue
+  public abstract static class GcpGceInstanceMonitoredResource extends MonitoredResource {
+
+    private static final String GCP_ACCOUNT_ID = firstNonNull(GcpMetadataConfig.getProjectId(), "");
+    private static final String GCP_INSTANCE_ID =
+        firstNonNull(GcpMetadataConfig.getInstanceId(), "");
+    private static final String GCP_ZONE = firstNonNull(GcpMetadataConfig.getZone(), "");
+
+    @Override
+    public ResourceType getResourceType() {
+      return ResourceType.GCP_GCE_INSTANCE;
+    }
+
+    /**
+     * Returns the GCP account number for the instance.
+     *
+     * @return the GCP account number for the instance.
+     * @since 0.13
+     */
+    public abstract String getAccount();
+
+    /**
+     * Returns the GCP GCE instance ID.
+     *
+     * @return the GCP GCE instance ID.
+     * @since 0.13
+     */
+    public abstract String getInstanceId();
+
+    /**
+     * Returns the GCP zone.
+     *
+     * @return the GCP zone.
+     * @since 0.13
+     */
+    public abstract String getZone();
+
+    static GcpGceInstanceMonitoredResource create() {
+      return new AutoValue_MonitoredResource_GcpGceInstanceMonitoredResource(
+          GCP_ACCOUNT_ID, GCP_INSTANCE_ID, GCP_ZONE);
+    }
+  }
+
+  /**
+   * {@link MonitoredResource} for GCP GKE container.
+   *
+   * @since 0.13
+   */
+  @Immutable
+  @AutoValue
+  public abstract static class GcpGkeContainerMonitoredResource extends MonitoredResource {
+
+    private static final String GCP_ACCOUNT_ID = firstNonNull(GcpMetadataConfig.getProjectId(), "");
+    private static final String GCP_CLUSTER_NAME =
+        firstNonNull(GcpMetadataConfig.getClusterName(), "");
+    private static final String GCP_CONTAINER_NAME =
+        firstNonNull(System.getenv("CONTAINER_NAME"), "");
+    private static final String GCP_NAMESPACE_ID = firstNonNull(System.getenv("NAMESPACE"), "");
+    private static final String GCP_INSTANCE_ID =
+        firstNonNull(GcpMetadataConfig.getInstanceId(), "");
+    private static final String GCP_POD_ID = firstNonNull(System.getenv("HOSTNAME"), "");
+    private static final String GCP_ZONE = firstNonNull(GcpMetadataConfig.getZone(), "");
+
+    @Override
+    public ResourceType getResourceType() {
+      return ResourceType.GCP_GKE_CONTAINER;
+    }
+
+    /**
+     * Returns the GCP account number for the instance.
+     *
+     * @return the GCP account number for the instance.
+     * @since 0.13
+     */
+    public abstract String getAccount();
+
+    /**
+     * Returns the GCP GKE cluster name.
+     *
+     * @return the GCP GKE cluster name.
+     * @since 0.13
+     */
+    public abstract String getClusterName();
+
+    /**
+     * Returns the GCP GKE container name.
+     *
+     * @return the GCP GKE container name.
+     * @since 0.13
+     */
+    public abstract String getContainerName();
+
+    /**
+     * Returns the GCP GKE namespace ID.
+     *
+     * @return the GCP GKE namespace ID.
+     * @since 0.13
+     */
+    public abstract String getNamespaceId();
+
+    /**
+     * Returns the GCP GKE instance ID.
+     *
+     * @return the GCP GKE instance ID.
+     * @since 0.13
+     */
+    public abstract String getInstanceId();
+
+    /**
+     * Returns the GCP GKE Pod ID.
+     *
+     * @return the GCP GKE Pod ID.
+     * @since 0.13
+     */
+    public abstract String getPodId();
+
+    /**
+     * Returns the GCP zone.
+     *
+     * @return the GCP zone.
+     * @since 0.13
+     */
+    public abstract String getZone();
+
+    static GcpGkeContainerMonitoredResource create() {
+      return new AutoValue_MonitoredResource_GcpGkeContainerMonitoredResource(
+          GCP_ACCOUNT_ID,
+          GCP_CLUSTER_NAME,
+          GCP_CONTAINER_NAME,
+          GCP_NAMESPACE_ID,
+          GCP_INSTANCE_ID,
+          GCP_POD_ID,
+          GCP_ZONE);
+    }
+  }
+}
diff --git a/contrib/monitored_resource_util/src/main/java/io/opencensus/contrib/monitoredresource/util/MonitoredResourceUtils.java b/contrib/monitored_resource_util/src/main/java/io/opencensus/contrib/monitoredresource/util/MonitoredResourceUtils.java
new file mode 100644
index 00000000..8ff0ff98
--- /dev/null
+++ b/contrib/monitored_resource_util/src/main/java/io/opencensus/contrib/monitoredresource/util/MonitoredResourceUtils.java
@@ -0,0 +1,54 @@
+/*
+ * Copyright 2018, OpenCensus Authors
+ *
+ * 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 io.opencensus.contrib.monitoredresource.util;
+
+import io.opencensus.contrib.monitoredresource.util.MonitoredResource.AwsEc2InstanceMonitoredResource;
+import io.opencensus.contrib.monitoredresource.util.MonitoredResource.GcpGceInstanceMonitoredResource;
+import io.opencensus.contrib.monitoredresource.util.MonitoredResource.GcpGkeContainerMonitoredResource;
+import javax.annotation.Nullable;
+
+/**
+ * Utilities for for auto detecting monitored resource based on the environment where the
+ * application is running.
+ *
+ * @since 0.13
+ */
+public final class MonitoredResourceUtils {
+
+  /**
+   * Returns a self-configured monitored resource, or {@code null} if the application is not running
+   * on a supported environment.
+   *
+   * @return a {@code MonitoredResource}.
+   * @since 0.13
+   */
+  @Nullable
+  public static MonitoredResource getDefaultResource() {
+    if (System.getenv("KUBERNETES_SERVICE_HOST") != null) {
+      return GcpGkeContainerMonitoredResource.create();
+    }
+    if (GcpMetadataConfig.getInstanceId() != null) {
+      return GcpGceInstanceMonitoredResource.create();
+    }
+    if (AwsIdentityDocUtils.isRunningOnAwsEc2()) {
+      return AwsEc2InstanceMonitoredResource.create();
+    }
+    return null;
+  }
+
+  private MonitoredResourceUtils() {}
+}
diff --git a/contrib/monitored_resource_util/src/main/java/io/opencensus/contrib/monitoredresource/util/ResourceType.java b/contrib/monitored_resource_util/src/main/java/io/opencensus/contrib/monitoredresource/util/ResourceType.java
new file mode 100644
index 00000000..f2816676
--- /dev/null
+++ b/contrib/monitored_resource_util/src/main/java/io/opencensus/contrib/monitoredresource/util/ResourceType.java
@@ -0,0 +1,47 @@
+/*
+ * Copyright 2018, OpenCensus Authors
+ *
+ * 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 io.opencensus.contrib.monitoredresource.util;
+
+/**
+ * {@link ResourceType} represents the type of supported monitored resources that can be
+ * automatically detected by OpenCensus.
+ *
+ * @since 0.13
+ */
+public enum ResourceType {
+
+  /**
+   * Resource for GCP GKE container.
+   *
+   * @since 0.13
+   */
+  GCP_GKE_CONTAINER,
+
+  /**
+   * Resource for GCP GCE instance.
+   *
+   * @since 0.13
+   */
+  GCP_GCE_INSTANCE,
+
+  /**
+   * Resource for AWS EC2 instance.
+   *
+   * @since 0.13
+   */
+  AWS_EC2_INSTANCE
+}
diff --git a/exporters/stats/stackdriver/src/test/java/io/opencensus/exporter/stats/stackdriver/AwsIdentityDocUtilsTest.java b/contrib/monitored_resource_util/src/test/java/io/opencensus/contrib/monitoredresource/util/AwsIdentityDocUtilsTest.java
index 9c15f087..77d98493 100644
--- a/exporters/stats/stackdriver/src/test/java/io/opencensus/exporter/stats/stackdriver/AwsIdentityDocUtilsTest.java
+++ b/contrib/monitored_resource_util/src/test/java/io/opencensus/contrib/monitoredresource/util/AwsIdentityDocUtilsTest.java
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-package io.opencensus.exporter.stats.stackdriver;
+package io.opencensus.contrib.monitoredresource.util;
 
 import static com.google.common.truth.Truth.assertThat;
 
diff --git a/contrib/monitored_resource_util/src/test/java/io/opencensus/contrib/monitoredresource/util/MonitoredResourceUtilsTest.java b/contrib/monitored_resource_util/src/test/java/io/opencensus/contrib/monitoredresource/util/MonitoredResourceUtilsTest.java
new file mode 100644
index 00000000..01927a2d
--- /dev/null
+++ b/contrib/monitored_resource_util/src/test/java/io/opencensus/contrib/monitoredresource/util/MonitoredResourceUtilsTest.java
@@ -0,0 +1,42 @@
+/*
+ * Copyright 2018, OpenCensus Authors
+ *
+ * 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 io.opencensus.contrib.monitoredresource.util;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
+
+/** Tests for {@link MonitoredResourceUtils}. */
+@RunWith(JUnit4.class)
+public class MonitoredResourceUtilsTest {
+
+  @Test
+  public void testGetDefaultResource() {
+    MonitoredResource resource = MonitoredResourceUtils.getDefaultResource();
+    if (System.getenv("KUBERNETES_SERVICE_HOST") != null) {
+      assertThat(resource.getResourceType()).isEqualTo(ResourceType.GCP_GKE_CONTAINER);
+    } else if (GcpMetadataConfig.getInstanceId() != null) {
+      assertThat(resource.getResourceType()).isEqualTo(ResourceType.GCP_GCE_INSTANCE);
+    } else if (AwsIdentityDocUtils.isRunningOnAwsEc2()) {
+      assertThat(resource.getResourceType()).isEqualTo(ResourceType.AWS_EC2_INSTANCE);
+    } else {
+      assertThat(resource).isNull();
+    }
+  }
+}
diff --git a/exporters/stats/stackdriver/build.gradle b/exporters/stats/stackdriver/build.gradle
index c2ed07aa..ebf59b70 100644
--- a/exporters/stats/stackdriver/build.gradle
+++ b/exporters/stats/stackdriver/build.gradle
@@ -9,6 +9,7 @@ dependencies {
     compileOnly libraries.auto_value
 
     compile project(':opencensus-api'),
+            project(':opencensus-contrib-monitored-resource-util'),
             libraries.google_auth
 
     compile (libraries.google_cloud_monitoring) {
diff --git a/exporters/stats/stackdriver/src/main/java/io/opencensus/exporter/stats/stackdriver/StackdriverExportUtils.java b/exporters/stats/stackdriver/src/main/java/io/opencensus/exporter/stats/stackdriver/StackdriverExportUtils.java
index f97217b5..8dc5f76c 100644
--- a/exporters/stats/stackdriver/src/main/java/io/opencensus/exporter/stats/stackdriver/StackdriverExportUtils.java
+++ b/exporters/stats/stackdriver/src/main/java/io/opencensus/exporter/stats/stackdriver/StackdriverExportUtils.java
@@ -29,7 +29,6 @@ import com.google.api.MetricDescriptor.MetricKind;
 import com.google.api.MonitoredResource;
 import com.google.cloud.MetadataConfig;
 import com.google.common.annotations.VisibleForTesting;
-import com.google.common.collect.ImmutableMultimap;
 import com.google.common.collect.Lists;
 import com.google.common.collect.Maps;
 import com.google.monitoring.v3.Point;
@@ -39,6 +38,11 @@ import com.google.monitoring.v3.TypedValue;
 import com.google.protobuf.Timestamp;
 import io.opencensus.common.Function;
 import io.opencensus.common.Functions;
+import io.opencensus.contrib.monitoredresource.util.MonitoredResource.AwsEc2InstanceMonitoredResource;
+import io.opencensus.contrib.monitoredresource.util.MonitoredResource.GcpGceInstanceMonitoredResource;
+import io.opencensus.contrib.monitoredresource.util.MonitoredResource.GcpGkeContainerMonitoredResource;
+import io.opencensus.contrib.monitoredresource.util.MonitoredResourceUtils;
+import io.opencensus.contrib.monitoredresource.util.ResourceType;
 import io.opencensus.stats.Aggregation;
 import io.opencensus.stats.AggregationData;
 import io.opencensus.stats.AggregationData.CountData;
@@ -72,10 +76,10 @@ final class StackdriverExportUtils {
   @VisibleForTesting static final String LABEL_DESCRIPTION = "OpenCensus TagKey";
   @VisibleForTesting static final String OPENCENSUS_TASK = "opencensus_task";
   @VisibleForTesting static final String OPENCENSUS_TASK_DESCRIPTION = "Opencensus task identifier";
-  @VisibleForTesting static final String GCP_GKE_CONTAINER = "gke_container";
-  @VisibleForTesting static final String GCP_GCE_INSTANCE = "gce_instance";
-  @VisibleForTesting static final String AWS_EC2_INSTANCE = "aws_ec2_instance";
-  @VisibleForTesting static final String GLOBAL = "global";
+  private static final String GCP_GKE_CONTAINER = "gke_container";
+  private static final String GCP_GCE_INSTANCE = "gce_instance";
+  private static final String AWS_EC2_INSTANCE = "aws_ec2_instance";
+  private static final String GLOBAL = "global";
 
   private static final Logger logger = Logger.getLogger(StackdriverExportUtils.class.getName());
   private static final String CUSTOM_METRIC_DOMAIN = "custom.googleapis.com";
@@ -356,135 +360,71 @@ final class StackdriverExportUtils {
         .build();
   }
 
-  private enum Label {
-    GcpClusterName("cluster_name"),
-    GcpContainerName("container_name"),
-    GcpNamespaceId("namespace_id"),
-    GcpInstanceId("instance_id"),
-    GcpInstanceName("instance_name"),
-    GcpGkePodId("pod_id"),
-    GcpZone("zone"),
-    AwsAccount("aws_account"),
-    AwsInstanceId("instance_id"),
-    AwsRegion("region");
-
-    private final String key;
-
-    Label(String key) {
-      this.key = key;
-    }
-
-    String getKey() {
-      return key;
-    }
-  }
-
-  private enum Resource {
-    GkeContainer(GCP_GKE_CONTAINER),
-    GceInstance(GCP_GCE_INSTANCE),
-    AwsEc2Instance(AWS_EC2_INSTANCE),
-    Global(GLOBAL);
-
-    private final String key;
-
-    Resource(String key) {
-      this.key = key;
-    }
-
-    String getKey() {
-      return key;
-    }
-  }
-
-  private static final ImmutableMultimap<Resource, Label> RESOURCE_TYPE_WITH_LABELS =
-      ImmutableMultimap.<Resource, Label>builder()
-          .putAll(
-              Resource.GkeContainer,
-              Label.GcpClusterName,
-              Label.GcpContainerName,
-              Label.GcpNamespaceId,
-              Label.GcpInstanceId,
-              Label.GcpGkePodId,
-              Label.GcpZone)
-          .putAll(Resource.GceInstance, Label.GcpInstanceId, Label.GcpZone)
-          .putAll(Resource.AwsEc2Instance, Label.AwsAccount, Label.AwsInstanceId, Label.AwsRegion)
-          .build();
-
-  /* Return a self-configured monitored Resource. */
+  /* Return a self-configured Stackdriver monitored resource. */
   static MonitoredResource getDefaultResource() {
-    Resource detectedResourceType = getAutoDetectedResourceType();
-    String resourceType = detectedResourceType.getKey();
-    MonitoredResource.Builder builder = MonitoredResource.newBuilder().setType(resourceType);
-    if (MetadataConfig.getProjectId() != null) {
-      // For default resource, always use the project id from MetadataConfig. This allows stats from
-      // other projects (e.g from GCE running in another project) to be collected.
-      builder.putLabels(PROJECT_ID_LABEL_KEY, MetadataConfig.getProjectId());
-    }
-    for (Label label : RESOURCE_TYPE_WITH_LABELS.get(detectedResourceType)) {
-      String value = getValue(label);
-      if (value == null) {
-        value = "";
+    MonitoredResource.Builder builder = MonitoredResource.newBuilder();
+    io.opencensus.contrib.monitoredresource.util.MonitoredResource autoDetectedResource =
+        MonitoredResourceUtils.getDefaultResource();
+    if (autoDetectedResource == null) {
+      builder.setType(GLOBAL);
+      if (MetadataConfig.getProjectId() != null) {
+        // For default global resource, always use the project id from MetadataConfig. This allows
+        // stats from other projects (e.g from GAE running in another project) to be collected.
+        builder.putLabels(PROJECT_ID_LABEL_KEY, MetadataConfig.getProjectId());
       }
-      // Label values can be null or empty, but each label key must have an associated value.
-      builder.putLabels(label.getKey(), value);
+      return builder.build();
     }
+    builder.setType(mapToStackdriverResourceType(autoDetectedResource.getResourceType()));
+    setMonitoredResourceLabelsForBuilder(builder, autoDetectedResource);
     return builder.build();
   }
 
-  @javax.annotation.Nullable
-  private static String getValue(Label label) {
-    String value;
-    switch (label) {
-      case GcpClusterName:
-        value = MetadataConfig.getClusterName();
-        break;
-      case GcpInstanceId:
-        value = MetadataConfig.getInstanceId();
-        break;
-      case GcpInstanceName:
-        value = System.getenv("GAE_INSTANCE");
-        break;
-      case GcpGkePodId:
-        value = System.getenv("HOSTNAME");
-        break;
-      case GcpZone:
-        value = MetadataConfig.getZone();
-        break;
-      case GcpContainerName:
-        value = System.getenv("CONTAINER_NAME");
-        break;
-      case GcpNamespaceId:
-        value = System.getenv("NAMESPACE");
-        break;
-      case AwsAccount:
-        value = AwsIdentityDocUtils.getValueFromAwsIdentityDocument("accountId");
-        break;
-      case AwsInstanceId:
-        value = AwsIdentityDocUtils.getValueFromAwsIdentityDocument("instanceId");
-        break;
-      case AwsRegion:
-        value = "aws:" + AwsIdentityDocUtils.getValueFromAwsIdentityDocument("region");
-        break;
-      default:
-        value = null;
-        break;
+  private static String mapToStackdriverResourceType(ResourceType resourceType) {
+    switch (resourceType) {
+      case GCP_GCE_INSTANCE:
+        return GCP_GCE_INSTANCE;
+      case GCP_GKE_CONTAINER:
+        return GCP_GKE_CONTAINER;
+      case AWS_EC2_INSTANCE:
+        return AWS_EC2_INSTANCE;
     }
-    return value;
+    throw new IllegalArgumentException("Unknown resource type.");
   }
 
-  /* Detects monitored Resource type using environment variables, else return global as default. */
-  private static Resource getAutoDetectedResourceType() {
-    if (System.getenv("KUBERNETES_SERVICE_HOST") != null) {
-      return Resource.GkeContainer;
-    }
-    if (MetadataConfig.getInstanceId() != null) {
-      return Resource.GceInstance;
-    }
-    if (AwsIdentityDocUtils.isRunningOnAwsEc2()) {
-      return Resource.AwsEc2Instance;
+  private static void setMonitoredResourceLabelsForBuilder(
+      MonitoredResource.Builder builder,
+      io.opencensus.contrib.monitoredresource.util.MonitoredResource autoDetectedResource) {
+    switch (autoDetectedResource.getResourceType()) {
+      case GCP_GCE_INSTANCE:
+        @SuppressWarnings("unchecked")
+        GcpGceInstanceMonitoredResource gcpGceInstanceMonitoredResource =
+            (GcpGceInstanceMonitoredResource) autoDetectedResource;
+        builder.putLabels(PROJECT_ID_LABEL_KEY, gcpGceInstanceMonitoredResource.getAccount());
+        builder.putLabels("instance_id", gcpGceInstanceMonitoredResource.getInstanceId());
+        builder.putLabels("zone", gcpGceInstanceMonitoredResource.getZone());
+        return;
+      case GCP_GKE_CONTAINER:
+        @SuppressWarnings("unchecked")
+        GcpGkeContainerMonitoredResource gcpGkeContainerMonitoredResource =
+            (GcpGkeContainerMonitoredResource) autoDetectedResource;
+        builder.putLabels(PROJECT_ID_LABEL_KEY, gcpGkeContainerMonitoredResource.getAccount());
+        builder.putLabels("cluster_name", gcpGkeContainerMonitoredResource.getClusterName());
+        builder.putLabels("container_name", gcpGkeContainerMonitoredResource.getContainerName());
+        builder.putLabels("namespace_id", gcpGkeContainerMonitoredResource.getNamespaceId());
+        builder.putLabels("instance_id", gcpGkeContainerMonitoredResource.getInstanceId());
+        builder.putLabels("pod_id", gcpGkeContainerMonitoredResource.getPodId());
+        builder.putLabels("zone", gcpGkeContainerMonitoredResource.getZone());
+        return;
+      case AWS_EC2_INSTANCE:
+        @SuppressWarnings("unchecked")
+        AwsEc2InstanceMonitoredResource awsEc2InstanceMonitoredResource =
+            (AwsEc2InstanceMonitoredResource) autoDetectedResource;
+        builder.putLabels("aws_account", awsEc2InstanceMonitoredResource.getAccount());
+        builder.putLabels("instance_id", awsEc2InstanceMonitoredResource.getInstanceId());
+        builder.putLabels("region", "aws:" + awsEc2InstanceMonitoredResource.getRegion());
+        return;
     }
-    // default Resource type
-    return Resource.Global;
+    throw new IllegalArgumentException("Unknown subclass of MonitoredResource.");
   }
 
   private StackdriverExportUtils() {}
diff --git a/exporters/stats/stackdriver/src/test/java/io/opencensus/exporter/stats/stackdriver/StackdriverExportUtilsTest.java b/exporters/stats/stackdriver/src/test/java/io/opencensus/exporter/stats/stackdriver/StackdriverExportUtilsTest.java
index 16e73b1f..a78a96ea 100644
--- a/exporters/stats/stackdriver/src/test/java/io/opencensus/exporter/stats/stackdriver/StackdriverExportUtilsTest.java
+++ b/exporters/stats/stackdriver/src/test/java/io/opencensus/exporter/stats/stackdriver/StackdriverExportUtilsTest.java
@@ -26,7 +26,6 @@ import com.google.api.Metric;
 import com.google.api.MetricDescriptor;
 import com.google.api.MetricDescriptor.MetricKind;
 import com.google.api.MonitoredResource;
-import com.google.cloud.MetadataConfig;
 import com.google.common.collect.ImmutableMap;
 import com.google.monitoring.v3.Point;
 import com.google.monitoring.v3.TimeInterval;
@@ -501,18 +500,4 @@ public class StackdriverExportUtilsTest {
                 .addPoints(StackdriverExportUtils.createPoint(sumData, cumulativeData, SUM))
                 .build());
   }
-
-  @Test
-  public void testGetDefaultResource() {
-    MonitoredResource resource = StackdriverExportUtils.getDefaultResource();
-    if (System.getenv("KUBERNETES_SERVICE_HOST") != null) {
-      assertThat(resource.getType()).isEqualTo(StackdriverExportUtils.GCP_GKE_CONTAINER);
-    } else if (MetadataConfig.getInstanceId() != null) {
-      assertThat(resource.getType()).isEqualTo(StackdriverExportUtils.GCP_GCE_INSTANCE);
-    } else if (AwsIdentityDocUtils.isRunningOnAwsEc2()) {
-      assertThat(resource.getType()).isEqualTo(StackdriverExportUtils.AWS_EC2_INSTANCE);
-    } else {
-      assertThat(resource.getType()).isEqualTo(StackdriverExportUtils.GLOBAL);
-    }
-  }
 }
diff --git a/settings.gradle b/settings.gradle
index 0d2617e2..3d9a0ee0 100644
--- a/settings.gradle
+++ b/settings.gradle
@@ -17,6 +17,7 @@ include ":opencensus-contrib-agent"
 include ":opencensus-contrib-grpc-metrics"
 include ":opencensus-contrib-grpc-util"
 include ":opencensus-contrib-http-util"
+include ":opencensus-contrib-monitored-resource-util"
 
 project(':opencensus-api').projectDir = "$rootDir/api" as File
 project(':opencensus-impl-core').projectDir = "$rootDir/impl_core" as File
@@ -27,6 +28,8 @@ project(':opencensus-contrib-agent').projectDir = "$rootDir/contrib/agent" as Fi
 project(':opencensus-contrib-grpc-metrics').projectDir = "$rootDir/contrib/grpc_metrics" as File
 project(':opencensus-contrib-grpc-util').projectDir = "$rootDir/contrib/grpc_util" as File
 project(':opencensus-contrib-http-util').projectDir = "$rootDir/contrib/http_util" as File
+project(':opencensus-contrib-monitored-resource-util').projectDir =
+        "$rootDir/contrib/monitored_resource_util" as File
 project(':opencensus-exporter-trace-instana').projectDir =
         "$rootDir/exporters/trace/instana" as File
 project(':opencensus-exporter-trace-logging').projectDir =