Refactor platform detection to enhance testing

detectors/resources-support/src/main/java/com/google/cloud/opentelemetry/detectors/AttributeKeys.java

@@ -0,0 +1,45 @@
+package com.google.cloud.opentelemetry.detectors;
+
+public final class AttributeKeys {
+  // GCE Attributes
+  public static final String GCE_PROJECT_ID = AttributeKeys.PROJECT_ID;
+  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;
+
+  // GKE Attributes
+  public static final String GKE_POD_NAME = "gke_pod_name";
+  public static final String GKE_NAMESPACE = "gke_namespace";
+  public static final String GKE_CONTAINER_NAME = "gke_container_name";
+  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;
+
+  static final String PROJECT_ID = "project_id";
+  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";
+}

detectors/resources-support/src/main/java/com/google/cloud/opentelemetry/detectors/CloudLocationUtil.java

@@ -1,18 +1,3 @@
-/*
- * Copyright 2023 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.cloud.opentelemetry.detectors;
 
 import java.util.Optional;

detectors/resources-support/src/main/java/com/google/cloud/opentelemetry/detectors/DetectedPlatform.java

@@ -0,0 +1,10 @@
+package com.google.cloud.opentelemetry.detectors;
+
+import java.util.Map;
+import java.util.Optional;
+
+public interface DetectedPlatform {
+  GCPPlatformDetector.SupportedPlatform getSupportedPlatform();
+
+  Map<String, Optional<String>> getAttributes();
+}

detectors/resources-support/src/main/java/com/google/cloud/opentelemetry/detectors/EnvironmentVariables.java

@@ -1,18 +1,3 @@
-/*
- * Copyright 2023 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.cloud.opentelemetry.detectors;
 
 /**

detectors/resources-support/src/main/java/com/google/cloud/opentelemetry/detectors/GCPMetadataConfig.java

@@ -1,18 +1,3 @@
-/*
- * Copyright 2023 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.cloud.opentelemetry.detectors;
 
 import java.io.BufferedReader;

detectors/resources-support/src/main/java/com/google/cloud/opentelemetry/detectors/GCPPlatformDetector.java

@@ -1,25 +1,10 @@
-/*
- * Copyright 2023 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.cloud.opentelemetry.detectors;
 
 import java.util.Optional;
 import java.util.function.Function;
 import java.util.stream.Stream;
 
-public final class GCPPlatformDetector {
+public class GCPPlatformDetector {
   public static final GCPPlatformDetector DEFAULT_INSTANCE = new GCPPlatformDetector();
 
   private final GCPMetadataConfig metadataConfig;
@@ -37,49 +22,74 @@ private GCPPlatformDetector() {
   }
 
   // Detects the GCP platform on which the application is running
-  public GCPPlatform detectPlatform() {
+  public DetectedPlatform detectPlatform() {
     if (!isRunningOnGcp()) {
-      return GCPPlatform.UNKNOWN_PLATFORM;
+      return generateDetectedPlatform(SupportedPlatform.UNKNOWN_PLATFORM);
     }
-    Function<EnvironmentVariables, Optional<GCPPlatform>> detectGKE =
+    Function<EnvironmentVariables, Optional<SupportedPlatform>> detectGKE =
         environmentVariables ->
             environmentVariables.get("KUBERNETES_SERVICE_HOST") != null
-                ? Optional.of(GCPPlatform.GOOGLE_KUBERNETES_ENGINE)
+                ? Optional.of(SupportedPlatform.GOOGLE_KUBERNETES_ENGINE)
                 : Optional.empty();
-    Function<EnvironmentVariables, Optional<GCPPlatform>> detectGCR =
+    Function<EnvironmentVariables, Optional<SupportedPlatform>> detectGCR =
         environmentVariables ->
             environmentVariables.get("K_CONFIGURATION") != null
                     && environmentVariables.get("FUNCTION_TARGET") == null
-                ? Optional.of(GCPPlatform.GOOGLE_CLOUD_RUN)
+                ? Optional.of(SupportedPlatform.GOOGLE_CLOUD_RUN)
                 : Optional.empty();
-    Function<EnvironmentVariables, Optional<GCPPlatform>> detectGCF =
+    Function<EnvironmentVariables, Optional<SupportedPlatform>> detectGCF =
         environmentVariables ->
             environmentVariables.get("FUNCTION_TARGET") != null
-                ? Optional.of(GCPPlatform.GOOGLE_CLOUD_FUNCTIONS)
+                ? Optional.of(SupportedPlatform.GOOGLE_CLOUD_FUNCTIONS)
                 : Optional.empty();
-    Function<EnvironmentVariables, Optional<GCPPlatform>> detectGAE =
+    Function<EnvironmentVariables, Optional<SupportedPlatform>> detectGAE =
         environmentVariables ->
             environmentVariables.get("GAE_SERVICE") != null
-                ? Optional.of(GCPPlatform.GOOGLE_APP_ENGINE)
+                ? Optional.of(SupportedPlatform.GOOGLE_APP_ENGINE)
                 : Optional.empty();
 
     // Order of detection functions matters here
-    Stream<Function<EnvironmentVariables, Optional<GCPPlatform>>> platforms =
+    Stream<Function<EnvironmentVariables, Optional<SupportedPlatform>>> platforms =
         Stream.of(detectGKE, detectGCR, detectGCF, detectGAE);
-    return platforms
-        .map(detectionFn -> detectionFn.apply(environmentVariables))
-        .filter(Optional::isPresent)
-        .map(Optional::get)
-        .findFirst()
-        .orElse(GCPPlatform.GOOGLE_COMPUTE_ENGINE); // defaults to GCE
+    SupportedPlatform platform =
+        platforms
+            .map(detectionFn -> detectionFn.apply(environmentVariables))
+            .filter(Optional::isPresent)
+            .map(Optional::get)
+            .findFirst()
+            .orElse(SupportedPlatform.GOOGLE_COMPUTE_ENGINE); // defaults to GCE
+    return generateDetectedPlatform(platform);
   }
 
   private boolean isRunningOnGcp() {
     return metadataConfig.getProjectId() != null && !metadataConfig.getProjectId().isEmpty();
   }
 
-  /** Enum containing various Google Cloud Platforms that can be detected by the support library. */
-  public enum GCPPlatform {
+  private DetectedPlatform generateDetectedPlatform(SupportedPlatform platform) {
+    DetectedPlatform detectedPlatform;
+    switch (platform) {
+      case GOOGLE_KUBERNETES_ENGINE:
+        detectedPlatform = new GoogleKubernetesEngine();
+        break;
+      case GOOGLE_CLOUD_RUN:
+        detectedPlatform = new GoogleCloudRun();
+        break;
+      case GOOGLE_CLOUD_FUNCTIONS:
+        detectedPlatform = new GoogleCloudFunction();
+        break;
+      case GOOGLE_APP_ENGINE:
+        detectedPlatform = new GoogleAppEngine();
+        break;
+      case GOOGLE_COMPUTE_ENGINE:
+        detectedPlatform = new GoogleComputeEngine();
+        break;
+      default:
+        detectedPlatform = new UnknownPlatform();
+    }
+    return detectedPlatform;
+  }
+
+  public enum SupportedPlatform {
     GOOGLE_COMPUTE_ENGINE,
     GOOGLE_KUBERNETES_ENGINE,
     GOOGLE_APP_ENGINE,