fetch project id on app engine platforms (#2304)

neozwu · web-flow · commit a625ab951a62 · 2017-08-22T11:57:37.000-07:00
* fetch project id on app engine platforms

* resolve dependency conflict

* reorder the sequence of fetching projectId

* use appId to infer projectId for GAE J7

* remove appengine API reflection
diff --git a/google-cloud-core/pom.xml b/google-cloud-core/pom.xml
@@ -39,6 +39,22 @@
       <version>20160810</version>
       <scope>compile</scope>
     </dependency>
+    <dependency>
+      <groupId>com.google.http-client</groupId>
+      <artifactId>google-http-client</artifactId>
+      <exclusions>
+        <exclusion>
+          <groupId>com.google.code.findbugs</groupId>
+          <artifactId>jsr305</artifactId>
+        </exclusion>
+      </exclusions>
+    </dependency>
+
+    <dependency>
+      <groupId>com.google.code.findbugs</groupId>
+      <artifactId>jsr305</artifactId>
+      <version>3.0.0</version>
+    </dependency>
     <dependency>
       <groupId>org.easymock</groupId>
       <artifactId>easymock</artifactId>
diff --git a/google-cloud-core/src/main/java/com/google/cloud/ServiceOptions.java b/google-cloud-core/src/main/java/com/google/cloud/ServiceOptions.java
@@ -20,6 +20,13 @@
 import static com.google.common.base.Preconditions.checkArgument;
 import static com.google.common.base.Preconditions.checkNotNull;
 
+import com.google.api.client.http.GenericUrl;
+import com.google.api.client.http.HttpHeaders;
+import com.google.api.client.http.HttpRequest;
+import com.google.api.client.http.HttpRequestFactory;
+import com.google.api.client.http.HttpResponse;
+import com.google.api.client.http.HttpTransport;
+import com.google.api.client.http.javanet.NetHttpTransport;
 import com.google.api.core.ApiClock;
 import com.google.api.core.CurrentMillisClock;
 import com.google.api.core.InternalApi;
@@ -39,7 +46,6 @@
 import java.io.InputStream;
 import java.io.ObjectInputStream;
 import java.io.Serializable;
-import java.lang.reflect.Method;
 import java.nio.charset.Charset;
 import java.util.Locale;
 import java.util.Objects;
@@ -381,30 +387,51 @@ private static boolean isWindows() {
   }
 
   protected static String getAppEngineProjectId() {
-    try {
-      Class<?> factoryClass =
-          Class.forName("com.google.appengine.api.appidentity.AppIdentityServiceFactory");
-      Class<?> serviceClass =
-          Class.forName("com.google.appengine.api.appidentity.AppIdentityService");
-      Method method = factoryClass.getMethod("getAppIdentityService");
-      Object appIdentityService = method.invoke(null);
-      method = serviceClass.getMethod("getServiceAccountName");
-      String serviceAccountName = (String) method.invoke(appIdentityService);
-      int indexOfAtSign = serviceAccountName.indexOf('@');
-      return serviceAccountName.substring(0, indexOfAtSign);
-    } catch (ClassNotFoundException exception) {
-      if (System.getProperty("com.google.appengine.runtime.version") != null) {
-        // Could not resolve appengine classes under GAE environment.
-        throw new RuntimeException("Google App Engine runtime detected "
-            + "(the environment variable \"com.google.appengine.runtime.version\" is set), "
-            + "but unable to resolve appengine-sdk classes. "
-            + "For more details see "
-            + "https://github.com/GoogleCloudPlatform/google-cloud-java/blob/master/APPENGINE.md");
+    String projectId = null;
+    if (PlatformInformation.isOnGAEStandard7()) {
+      projectId = getAppEngineProjectIdFromAppId();
+    } else {
+      //for GAE flex and standard Java 8 environment
+      projectId = System.getenv("GOOGLE_CLOUD_PROJECT");
+      if (projectId == null) {
+        projectId = System.getenv("GCLOUD_PROJECT");
+      }
+      if (projectId == null) {
+        projectId = getAppEngineProjectIdFromAppId();
+      }
+      if (projectId == null) {
+        try {
+          projectId = getAppEngineProjectIdFromMetadataServer();
+        } catch (IOException ignore) {
+          projectId = null;
+        }
       }
-      return null;
-    } catch (Exception ignore) {
-      return null;
     }
+    return projectId;
+  }
+
+  protected static String getAppEngineProjectIdFromAppId() {
+    String projectId = getAppEngineAppId();
+    if (projectId != null && projectId.contains(":")) {
+      int colonIndex = projectId.indexOf(":");
+      projectId = projectId.substring(colonIndex + 1);
+    }
+    return projectId;
+  }
+
+  private static String getAppEngineProjectIdFromMetadataServer() throws IOException {
+    String metadata = "http://metadata.google.internal";
+    String projectIdURL = "/computeMetadata/v1/project/project-id";
+    GenericUrl url = new GenericUrl(metadata + projectIdURL);
+
+    HttpTransport netHttpTransport = new NetHttpTransport();
+    HttpRequestFactory requestFactory = netHttpTransport.createRequestFactory();
+    HttpRequest request = requestFactory.buildGetRequest(url)
+            .setConnectTimeout(500)
+            .setReadTimeout(500)
+            .setHeaders(new HttpHeaders().set("Metadata-Flavor", "Google"));
+    HttpResponse response = request.execute();
+    return response.parseAsString();
   }
 
   protected static String getServiceAccountProjectId() {
