Unify gcp resource detector (#2747)

Author: psx95

gcp-resources/build.gradle.kts

@@ -12,9 +12,6 @@ dependencies {
   compileOnly("io.opentelemetry:opentelemetry-api-incubator")
   api("io.opentelemetry:opentelemetry-sdk")
 
-  // Provides GCP resource detection support
-  implementation("com.google.cloud.opentelemetry:detector-resources-support:0.36.0")
-
   testImplementation("io.opentelemetry.semconv:opentelemetry-semconv-incubating")
 
   compileOnly("io.opentelemetry:opentelemetry-sdk-extension-autoconfigure")
@@ -26,7 +23,9 @@ dependencies {
   testImplementation("io.opentelemetry:opentelemetry-sdk-testing")
 
   testImplementation("org.mockito:mockito-core")
+  testImplementation("org.mockito:mockito-inline")
   testImplementation("com.google.guava:guava")
 
   testImplementation("org.junit.jupiter:junit-jupiter-api")
+  testImplementation("com.github.tomakehurst:wiremock-jre8:2.35.0")
 }

gcp-resources/src/main/java/io/opentelemetry/contrib/gcp/resource/AttributeKeys.java

@@ -0,0 +1,56 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package io.opentelemetry.contrib.gcp.resource;
+
+/**
+ * Contains constants that act as keys for the known attributes for {@link
+ * GcpPlatformDetector.SupportedPlatform}s.
+ */
+final class AttributeKeys {
+  private AttributeKeys() {}
+
+  // GCE Attributes
+  public static final String GCE_AVAILABILITY_ZONE = AttributeKeys.AVAILABILITY_ZONE;
+  public static final String GCE_CLOUD_REGION = AttributeKeys.CLOUD_REGION;
+  public static final String GCE_INSTANCE_ID = AttributeKeys.INSTANCE_ID;
+  public static final String GCE_INSTANCE_NAME = AttributeKeys.INSTANCE_NAME;
+  public static final String GCE_MACHINE_TYPE = AttributeKeys.MACHINE_TYPE;
+  public static final String GCE_INSTANCE_HOSTNAME = "instance_hostname";
+
+  // GKE Attributes
+  public static final String GKE_CLUSTER_NAME = "gke_cluster_name";
+  public static final String GKE_CLUSTER_LOCATION_TYPE = "gke_cluster_location_type";
+  public static final String GKE_CLUSTER_LOCATION = "gke_cluster_location";
+  public static final String GKE_HOST_ID = AttributeKeys.INSTANCE_ID;
+
+  // GKE Location Constants
+  public static final String GKE_LOCATION_TYPE_ZONE = "ZONE";
+  public static final String GKE_LOCATION_TYPE_REGION = "REGION";
+
+  // GAE Attributes
+  public static final String GAE_MODULE_NAME = "gae_module_name";
+  public static final String GAE_APP_VERSION = "gae_app_version";
+  public static final String GAE_INSTANCE_ID = AttributeKeys.INSTANCE_ID;
+  public static final String GAE_AVAILABILITY_ZONE = AttributeKeys.AVAILABILITY_ZONE;
+  public static final String GAE_CLOUD_REGION = AttributeKeys.CLOUD_REGION;
+
+  // Google Serverless Compute Attributes
+  public static final String SERVERLESS_COMPUTE_NAME = "serverless_compute_name";
+  public static final String SERVERLESS_COMPUTE_REVISION = "serverless_compute_revision";
+  public static final String SERVERLESS_COMPUTE_AVAILABILITY_ZONE = AttributeKeys.AVAILABILITY_ZONE;
+  public static final String SERVERLESS_COMPUTE_CLOUD_REGION = AttributeKeys.CLOUD_REGION;
+  public static final String SERVERLESS_COMPUTE_INSTANCE_ID = AttributeKeys.INSTANCE_ID;
+
+  // Cloud Run Job Specific Attributes
+  public static final String GCR_JOB_EXECUTION_KEY = "gcr_job_execution_key";
+  public static final String GCR_JOB_TASK_INDEX = "gcr_job_task_index";
+
+  static final String AVAILABILITY_ZONE = "availability_zone";
+  static final String CLOUD_REGION = "cloud_region";
+  static final String INSTANCE_ID = "instance_id";
+  static final String INSTANCE_NAME = "instance_name";
+  static final String MACHINE_TYPE = "machine_type";
+}

gcp-resources/src/main/java/io/opentelemetry/contrib/gcp/resource/DetectedPlatform.java

@@ -0,0 +1,36 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package io.opentelemetry.contrib.gcp.resource;
+
+import java.util.Map;
+
+/** Represents a GCP specific platform on which a cloud application can run. */
+interface DetectedPlatform {
+  /**
+   * Method to retrieve the underlying compute platform on which application is running.
+   *
+   * @return the {@link GcpPlatformDetector.SupportedPlatform} representing the Google Cloud
+   *     platform on which application is running.
+   */
+  GcpPlatformDetector.SupportedPlatform getSupportedPlatform();
+
+  /**
+   * Method to retrieve the GCP Project ID in which the GCP specific platform exists. Every valid
+   * platform must have a GCP Project ID associated with it.
+   *
+   * @return the Google Cloud project ID.
+   */
+  String getProjectId();
+
+  /**
+   * Method to retrieve the attributes associated with the compute platform on which the application
+   * is running as key-value pairs. The valid keys to query on this {@link Map} are specified in the
+   * {@link AttributeKeys}.
+   *
+   * @return a {@link Map} of attributes specific to the underlying compute platform.
+   */
+  Map<String, String> getAttributes();
+}

gcp-resources/src/main/java/io/opentelemetry/contrib/gcp/resource/EnvironmentVariables.java

@@ -0,0 +1,23 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package io.opentelemetry.contrib.gcp.resource;
+
+/**
+ * Provides API to fetch environment variables. This is useful in order to create a mock class for
+ * testing.
+ */
+interface EnvironmentVariables {
+  /** Returns the current environment variables of the platform this is running in. */
+  EnvironmentVariables DEFAULT_INSTANCE = System::getenv;
+
+  /**
+   * Grabs the system environment variable. Returns null on failure.
+   *
+   * @param key the key of the environment variable in {@code System.getenv()}
+   * @return the value received by {@code System.getenv(key)}
+   */
+  String get(String key);
+}

gcp-resources/src/main/java/io/opentelemetry/contrib/gcp/resource/GCPResourceProvider.java

@@ -5,30 +5,30 @@
 
 package io.opentelemetry.contrib.gcp.resource;
 
-import static com.google.cloud.opentelemetry.detection.AttributeKeys.GAE_APP_VERSION;
-import static com.google.cloud.opentelemetry.detection.AttributeKeys.GAE_AVAILABILITY_ZONE;
-import static com.google.cloud.opentelemetry.detection.AttributeKeys.GAE_CLOUD_REGION;
-import static com.google.cloud.opentelemetry.detection.AttributeKeys.GAE_INSTANCE_ID;
-import static com.google.cloud.opentelemetry.detection.AttributeKeys.GAE_MODULE_NAME;
-import static com.google.cloud.opentelemetry.detection.AttributeKeys.GCE_AVAILABILITY_ZONE;
-import static com.google.cloud.opentelemetry.detection.AttributeKeys.GCE_CLOUD_REGION;
-import static com.google.cloud.opentelemetry.detection.AttributeKeys.GCE_INSTANCE_HOSTNAME;
-import static com.google.cloud.opentelemetry.detection.AttributeKeys.GCE_INSTANCE_ID;
-import static com.google.cloud.opentelemetry.detection.AttributeKeys.GCE_INSTANCE_NAME;
-import static com.google.cloud.opentelemetry.detection.AttributeKeys.GCE_MACHINE_TYPE;
-import static com.google.cloud.opentelemetry.detection.AttributeKeys.GCR_JOB_EXECUTION_KEY;
-import static com.google.cloud.opentelemetry.detection.AttributeKeys.GCR_JOB_TASK_INDEX;
-import static com.google.cloud.opentelemetry.detection.AttributeKeys.GKE_CLUSTER_LOCATION;
-import static com.google.cloud.opentelemetry.detection.AttributeKeys.GKE_CLUSTER_LOCATION_TYPE;
-import static com.google.cloud.opentelemetry.detection.AttributeKeys.GKE_CLUSTER_NAME;
-import static com.google.cloud.opentelemetry.detection.AttributeKeys.GKE_HOST_ID;
-import static com.google.cloud.opentelemetry.detection.AttributeKeys.GKE_LOCATION_TYPE_REGION;
-import static com.google.cloud.opentelemetry.detection.AttributeKeys.GKE_LOCATION_TYPE_ZONE;
-import static com.google.cloud.opentelemetry.detection.AttributeKeys.SERVERLESS_COMPUTE_AVAILABILITY_ZONE;
-import static com.google.cloud.opentelemetry.detection.AttributeKeys.SERVERLESS_COMPUTE_CLOUD_REGION;
-import static com.google.cloud.opentelemetry.detection.AttributeKeys.SERVERLESS_COMPUTE_INSTANCE_ID;
-import static com.google.cloud.opentelemetry.detection.AttributeKeys.SERVERLESS_COMPUTE_NAME;
-import static com.google.cloud.opentelemetry.detection.AttributeKeys.SERVERLESS_COMPUTE_REVISION;
+import static io.opentelemetry.contrib.gcp.resource.AttributeKeys.GAE_APP_VERSION;
+import static io.opentelemetry.contrib.gcp.resource.AttributeKeys.GAE_AVAILABILITY_ZONE;
+import static io.opentelemetry.contrib.gcp.resource.AttributeKeys.GAE_CLOUD_REGION;
+import static io.opentelemetry.contrib.gcp.resource.AttributeKeys.GAE_INSTANCE_ID;
+import static io.opentelemetry.contrib.gcp.resource.AttributeKeys.GAE_MODULE_NAME;
+import static io.opentelemetry.contrib.gcp.resource.AttributeKeys.GCE_AVAILABILITY_ZONE;
+import static io.opentelemetry.contrib.gcp.resource.AttributeKeys.GCE_CLOUD_REGION;
+import static io.opentelemetry.contrib.gcp.resource.AttributeKeys.GCE_INSTANCE_HOSTNAME;
+import static io.opentelemetry.contrib.gcp.resource.AttributeKeys.GCE_INSTANCE_ID;
+import static io.opentelemetry.contrib.gcp.resource.AttributeKeys.GCE_INSTANCE_NAME;
+import static io.opentelemetry.contrib.gcp.resource.AttributeKeys.GCE_MACHINE_TYPE;
+import static io.opentelemetry.contrib.gcp.resource.AttributeKeys.GCR_JOB_EXECUTION_KEY;
+import static io.opentelemetry.contrib.gcp.resource.AttributeKeys.GCR_JOB_TASK_INDEX;
+import static io.opentelemetry.contrib.gcp.resource.AttributeKeys.GKE_CLUSTER_LOCATION;
+import static io.opentelemetry.contrib.gcp.resource.AttributeKeys.GKE_CLUSTER_LOCATION_TYPE;
+import static io.opentelemetry.contrib.gcp.resource.AttributeKeys.GKE_CLUSTER_NAME;
+import static io.opentelemetry.contrib.gcp.resource.AttributeKeys.GKE_HOST_ID;
+import static io.opentelemetry.contrib.gcp.resource.AttributeKeys.GKE_LOCATION_TYPE_REGION;
+import static io.opentelemetry.contrib.gcp.resource.AttributeKeys.GKE_LOCATION_TYPE_ZONE;
+import static io.opentelemetry.contrib.gcp.resource.AttributeKeys.SERVERLESS_COMPUTE_AVAILABILITY_ZONE;
+import static io.opentelemetry.contrib.gcp.resource.AttributeKeys.SERVERLESS_COMPUTE_CLOUD_REGION;
+import static io.opentelemetry.contrib.gcp.resource.AttributeKeys.SERVERLESS_COMPUTE_INSTANCE_ID;
+import static io.opentelemetry.contrib.gcp.resource.AttributeKeys.SERVERLESS_COMPUTE_NAME;
+import static io.opentelemetry.contrib.gcp.resource.AttributeKeys.SERVERLESS_COMPUTE_REVISION;
 import static io.opentelemetry.contrib.gcp.resource.IncubatingAttributes.CLOUD_ACCOUNT_ID;
 import static io.opentelemetry.contrib.gcp.resource.IncubatingAttributes.CLOUD_AVAILABILITY_ZONE;
 import static io.opentelemetry.contrib.gcp.resource.IncubatingAttributes.CLOUD_PLATFORM;
@@ -50,8 +50,6 @@
 import static io.opentelemetry.contrib.gcp.resource.IncubatingAttributes.HOST_TYPE;
 import static io.opentelemetry.contrib.gcp.resource.IncubatingAttributes.K8S_CLUSTER_NAME;
 
-import com.google.cloud.opentelemetry.detection.DetectedPlatform;
-import com.google.cloud.opentelemetry.detection.GCPPlatformDetector;
 import io.opentelemetry.api.common.Attributes;
 import io.opentelemetry.api.common.AttributesBuilder;
 import io.opentelemetry.sdk.autoconfigure.spi.ConfigProperties;
@@ -66,15 +64,15 @@ public class GCPResourceProvider implements ConditionalResourceProvider {
 
   private static final Logger LOGGER = Logger.getLogger(GCPResourceProvider.class.getSimpleName());
 
-  private final GCPPlatformDetector detector;
+  private final GcpPlatformDetector detector;
 
   // for testing only
-  GCPResourceProvider(GCPPlatformDetector detector) {
+  GCPResourceProvider(GcpPlatformDetector detector) {
     this.detector = detector;
   }
 
   public GCPResourceProvider() {
-    this.detector = GCPPlatformDetector.DEFAULT_INSTANCE;
+    this.detector = GcpPlatformDetector.DEFAULT_INSTANCE;
   }
 
   @Override
@@ -91,7 +89,7 @@ public final boolean shouldApply(ConfigProperties config, Resource existing) {
   public Attributes getAttributes() {
     DetectedPlatform detectedPlatform = detector.detectPlatform();
     if (detectedPlatform.getSupportedPlatform()
-        == GCPPlatformDetector.SupportedPlatform.UNKNOWN_PLATFORM) {
+        == GcpPlatformDetector.SupportedPlatform.UNKNOWN_PLATFORM) {
       return Attributes.empty();
     }
 

gcp-resources/src/main/java/io/opentelemetry/contrib/gcp/resource/GcpMetadataConfig.java

@@ -0,0 +1,163 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package io.opentelemetry.contrib.gcp.resource;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.net.HttpURLConnection;
+import java.net.URI;
+import java.net.URL;
+import java.nio.charset.StandardCharsets;
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
+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 {
+  static final GcpMetadataConfig DEFAULT_INSTANCE = new GcpMetadataConfig();
+
+  private static final String DEFAULT_URL = "http://metadata.google.internal/computeMetadata/v1/";
+  private final String url;
+  private final Map<String, String> cachedAttributes = new ConcurrentHashMap<>();
+
+  private GcpMetadataConfig() {
+    this.url = DEFAULT_URL;
+  }
+
+  // For testing only
+  GcpMetadataConfig(String url) {
+    this.url = url;
+  }
+
+  // Returns null on failure to retrieve from metadata server
+  String getProjectId() {
+    return getAttribute("project/project-id");
+  }
+
+  /**
+   * Method to extract cloud availability zone from the metadata server.
+   *
+   * <p>Example response: projects/640212054955/zones/australia-southeast1-a
+   *
+   * <p>Example zone: australia-southeast1-a
+   *
+   * @return the extracted zone from the metadata server response or null in case of failure to
+   *     retrieve from metadata server.
+   */
+  String getZone() {
+    String zone = getAttribute("instance/zone");
+    if (zone != null && zone.contains("/")) {
+      zone = zone.substring(zone.lastIndexOf('/') + 1);
+    }
+    return zone;
+  }
+
+  /**
+   * Use this method only when the region cannot be parsed from the zone. Known use-cases of this
+   * method involve detecting region in GAE standard environment.
+   *
+   * <p>Example response: projects/5689182099321/regions/us-central1.
+   *
+   * @return the retrieved region or null in case of failure to retrieve from metadata server
+   */
+  String getRegion() {
+    String region = getAttribute("instance/region");
+    if (region != null && region.contains("/")) {
+      region = region.substring(region.lastIndexOf('/') + 1);
+    }
+    return region;
+  }
+
+  /**
+   * Use this method to parse region from zone.
+   *
+   * <p>Example region: australia-southeast1
+   *
+   * @return parsed region from the zone, if zone is not found or is invalid, this method returns
+   *     null.
+   */
+  @Nullable
+  String getRegionFromZone() {
+    String region = null;
+    String zone = getZone();
+    if (zone != null && !zone.isEmpty()) {
+      // Parsing required to scope up to a region
+      String[] splitArr = zone.split("-");
+      if (splitArr.length > 2) {
+        region = String.join("-", splitArr[0], splitArr[1]);
+      }
+    }
+    return region;
+  }
+
+  // Example response: projects/640212054955/machineTypes/e2-medium
+  String getMachineType() {
+    String machineType = getAttribute("instance/machine-type");
+    if (machineType != null && machineType.contains("/")) {
+      machineType = machineType.substring(machineType.lastIndexOf('/') + 1);
+    }
+    return machineType;
+  }
+
+  // Returns null on failure to retrieve from metadata server
+  String getInstanceId() {
+    return getAttribute("instance/id");
+  }
+
+  // Returns null on failure to retrieve from metadata server
+  String getClusterName() {
+    return getAttribute("instance/attributes/cluster-name");
+  }
+
+  // Returns null on failure to retrieve from metadata server
+  String getClusterLocation() {
+    return getAttribute("instance/attributes/cluster-location");
+  }
+
+  // Returns null on failure to retrieve from metadata server
+  String getInstanceHostName() {
+    return getAttribute("instance/hostname");
+  }
+
+  // Returns null on failure to retrieve from metadata server
+  String getInstanceName() {
+    return getAttribute("instance/name");
+  }
+
+  // Returns null on failure to retrieve from metadata server
+  private String getAttribute(String attributeName) {
+    return cachedAttributes.computeIfAbsent(attributeName, this::fetchAttribute);
+  }
+
+  // Return the attribute received at <attributeName> relative path or null on
+  // failure
+  @Nullable
+  private String fetchAttribute(String attributeName) {
+    try {
+      URL url = URI.create(this.url + attributeName).toURL();
+      HttpURLConnection connection = (HttpURLConnection) url.openConnection();
+      connection.setRequestProperty("Metadata-Flavor", "Google");
+      if (connection.getResponseCode() == 200
+          && "Google".equals(connection.getHeaderField("Metadata-Flavor"))) {
+        InputStream input = connection.getInputStream();
+        try (BufferedReader reader =
+            new BufferedReader(new InputStreamReader(input, StandardCharsets.UTF_8))) {
+          return reader.readLine();
+        }
+      }
+    } catch (IOException ignore) {
+      // ignore
+    }
+    return null;
+  }
+}