Try resolving project id from Google credentials if not provided

Author: gustavovnicius

gcp-auth-extension/README.md

@@ -34,14 +34,13 @@ The extension can be configured either by environment variables or system proper
 
 Here is a list of required and optional configuration available for the extension:
 
-#### Required Config
+#### Optional Config
 
 - `GOOGLE_CLOUD_PROJECT`: Environment variable that represents the Google Cloud Project ID to which the telemetry needs to be exported.
 
   - Can also be configured using `google.cloud.project` system property.
-  - This is a required option, the agent configuration will fail if this option is not set.
-
-#### Optional Config
+  - If neither of these options are set, the extension will attempt to infer the project id from the credentials used, however notice that not all credentials implementations will be able to provide a project id, so the inference is only a best-effort attempt.
+  - **Important Note**: The agent configuration will fail if this option is not set and cannot be inferred.
 
 - `GOOGLE_CLOUD_QUOTA_PROJECT`: Environment variable that represents the Google Cloud Quota Project ID which will be charged for the GCP API usage. To learn more about a *quota project*, see the [Quota project overview](https://cloud.google.com/docs/quotas/quota-project) page. Additional details about configuring the *quota project* can be found on the [Set the quota project](https://cloud.google.com/docs/quotas/set-quota-project) page.
 

gcp-auth-extension/build.gradle.kts

@@ -24,13 +24,14 @@ dependencies {
   compileOnly("io.opentelemetry:opentelemetry-exporter-otlp")
 
   // Only dependencies added to `implementation` configuration will be picked up by Shadow plugin
-  implementation("com.google.auth:google-auth-library-oauth2-http:1.39.1")
+  implementation("com.google.auth:google-auth-library-oauth2-http:1.40.0")
 
   // Test dependencies
   testCompileOnly("com.google.auto.service:auto-service-annotations")
   testRuntimeOnly("org.junit.jupiter:junit-jupiter-engine")
   testImplementation("org.junit.jupiter:junit-jupiter-api")
   testCompileOnly("org.junit.jupiter:junit-jupiter-params")
+  testImplementation("org.junit-pioneer:junit-pioneer")
 
   testImplementation("io.opentelemetry:opentelemetry-api")
   testImplementation("io.opentelemetry:opentelemetry-exporter-otlp")

gcp-auth-extension/src/main/java/io/opentelemetry/contrib/gcp/auth/GcpAuthAutoConfigurationCustomizerProvider.java

@@ -5,13 +5,13 @@
 
 package io.opentelemetry.contrib.gcp.auth;
 
-import static io.opentelemetry.api.common.AttributeKey.stringKey;
 import static java.util.Arrays.stream;
 import static java.util.stream.Collectors.joining;
 import static java.util.stream.Collectors.toMap;
 
 import com.google.auth.oauth2.GoogleCredentials;
 import com.google.auto.service.AutoService;
+import io.opentelemetry.api.common.AttributeKey;
 import io.opentelemetry.api.common.Attributes;
 import io.opentelemetry.contrib.gcp.auth.GoogleAuthException.Reason;
 import io.opentelemetry.exporter.otlp.http.metrics.OtlpHttpMetricExporter;
@@ -25,6 +25,7 @@
 import io.opentelemetry.sdk.autoconfigure.spi.AutoConfigurationCustomizer;
 import io.opentelemetry.sdk.autoconfigure.spi.AutoConfigurationCustomizerProvider;
 import io.opentelemetry.sdk.autoconfigure.spi.ConfigProperties;
+import io.opentelemetry.sdk.autoconfigure.spi.ConfigurationException;
 import io.opentelemetry.sdk.metrics.export.MetricExporter;
 import io.opentelemetry.sdk.resources.Resource;
 import io.opentelemetry.sdk.trace.export.SpanExporter;
@@ -111,7 +112,12 @@ public void customize(@Nonnull AutoConfigurationCustomizer autoConfiguration) {
         .addMetricExporterCustomizer(
             (metricExporter, configProperties) ->
                 customizeMetricExporter(metricExporter, credentials, configProperties))
-        .addResourceCustomizer(GcpAuthAutoConfigurationCustomizerProvider::customizeResource);
+        .addResourceCustomizer(
+            (resource, configProperties) -> {
+              String gcpProjectId = getGoogleProjectId(configProperties, credentials);
+
+              return customizeResource(resource, gcpProjectId);
+            });
   }
 
   @Override
@@ -228,10 +234,36 @@ private static Map<String, String> getRequiredHeaderMap(
   }
 
   // Updates the current resource with the attributes required for ingesting OTLP data on GCP.
-  private static Resource customizeResource(Resource resource, ConfigProperties configProperties) {
-    String gcpProjectId =
-        ConfigurableOption.GOOGLE_CLOUD_PROJECT.getConfiguredValue(configProperties);
-    Resource res = Resource.create(Attributes.of(stringKey(GCP_USER_PROJECT_ID_KEY), gcpProjectId));
+  private static Resource customizeResource(Resource resource, String gcpProjectId) {
+    Resource res =
+        Resource.create(
+            Attributes.of(AttributeKey.stringKey(GCP_USER_PROJECT_ID_KEY), gcpProjectId));
     return resource.merge(res);
   }
+
+  /**
+   * Retrieves the Google Cloud Project ID from the configuration properties, falling back to
+   * google-cloud-core's ServiceOptions project ID resolution if not explicitly set.
+   *
+   * @param configProperties The configuration properties containing the GCP project ID.
+   * @return The Google Cloud Project ID.
+   */
+  @Nonnull
+  static String getGoogleProjectId(
+      ConfigProperties configProperties, GoogleCredentials credentials) {
+    String googleProjectId =
+        ConfigurableOption.GOOGLE_CLOUD_PROJECT.getConfiguredValueWithFallback(
+            configProperties, credentials::getProjectId);
+
+    if (googleProjectId == null || googleProjectId.isEmpty()) {
+      throw new ConfigurationException(
+          String.format(
+              "GCP Authentication Extension not configured properly: %s not configured. Configure it by exporting environment variable %s or system property %s",
+              ConfigurableOption.GOOGLE_CLOUD_PROJECT,
+              ConfigurableOption.GOOGLE_CLOUD_PROJECT.getEnvironmentVariable(),
+              ConfigurableOption.GOOGLE_CLOUD_PROJECT.getSystemProperty()));
+    }
+
+    return googleProjectId;
+  }
 }

gcp-auth-extension/src/test/java/io/opentelemetry/contrib/gcp/auth/GcpAuthAutoConfigurationCustomizerProviderTest.java

@@ -12,6 +12,8 @@
 import static io.opentelemetry.contrib.gcp.auth.GcpAuthAutoConfigurationCustomizerProvider.SIGNAL_TYPE_TRACES;
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.assertj.core.api.Assertions.assertThatThrownBy;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.when;
@@ -40,6 +42,7 @@
 import io.opentelemetry.sdk.autoconfigure.internal.SpiHelper;
 import io.opentelemetry.sdk.autoconfigure.spi.ConfigProperties;
 import io.opentelemetry.sdk.autoconfigure.spi.ConfigurationException;
+import io.opentelemetry.sdk.autoconfigure.spi.internal.DefaultConfigProperties;
 import io.opentelemetry.sdk.autoconfigure.spi.metrics.ConfigurableMetricExporterProvider;
 import io.opentelemetry.sdk.autoconfigure.spi.traces.ConfigurableSpanExporterProvider;
 import io.opentelemetry.sdk.common.CompletableResultCode;
@@ -74,6 +77,8 @@
 import org.junit.jupiter.params.ParameterizedTest;
 import org.junit.jupiter.params.provider.Arguments;
 import org.junit.jupiter.params.provider.MethodSource;
+import org.junitpioneer.jupiter.ClearSystemProperty;
+import org.junitpioneer.jupiter.SetSystemProperty;
 import org.mockito.ArgumentCaptor;
 import org.mockito.Captor;
 import org.mockito.Mock;
@@ -538,6 +543,51 @@ void testTargetSignalsBehavior(TargetSignalBehavior testCase) {
     }
   }
 
+  @Test
+  @ClearSystemProperty(key = "GOOGLE_CLOUD_PROJECT")
+  @ClearSystemProperty(key = "google.cloud.project")
+  void testThrowsExceptionIfGoogleProjectIsNotFound() {
+    DefaultConfigProperties configProperties =
+        DefaultConfigProperties.create(Collections.emptyMap(), Mockito.mock(ComponentLoader.class));
+
+    Mockito.when(mockedGoogleCredentials.getProjectId()).thenReturn(null);
+
+    assertThrows(
+        ConfigurationException.class,
+        () ->
+            GcpAuthAutoConfigurationCustomizerProvider.getGoogleProjectId(
+                configProperties, mockedGoogleCredentials));
+  }
+
+  @Test
+  @SetSystemProperty(key = "google.cloud.project", value = DUMMY_GCP_RESOURCE_PROJECT_ID)
+  void testResolveGoogleProjectIdFromSystemProperty() {
+    DefaultConfigProperties configProperties =
+        DefaultConfigProperties.create(Collections.emptyMap(), Mockito.mock(ComponentLoader.class));
+
+    assertEquals(
+        DUMMY_GCP_RESOURCE_PROJECT_ID,
+        GcpAuthAutoConfigurationCustomizerProvider.getGoogleProjectId(
+            configProperties, mockedGoogleCredentials));
+
+    Mockito.verifyNoInteractions(mockedGoogleCredentials);
+  }
+
+  @Test
+  @ClearSystemProperty(key = "google.cloud.project")
+  @ClearSystemProperty(key = "GOOGLE_CLOUD_PROJECT")
+  void testResolveGoogleProjectIdFromCredentials() {
+    DefaultConfigProperties configProperties =
+        DefaultConfigProperties.create(Collections.emptyMap(), Mockito.mock(ComponentLoader.class));
+
+    Mockito.when(mockedGoogleCredentials.getProjectId()).thenReturn(DUMMY_GCP_RESOURCE_PROJECT_ID);
+
+    assertEquals(
+        DUMMY_GCP_RESOURCE_PROJECT_ID,
+        GcpAuthAutoConfigurationCustomizerProvider.getGoogleProjectId(
+            configProperties, mockedGoogleCredentials));
+  }
+
   /** Test cases specifying expected behavior for GOOGLE_OTEL_AUTH_TARGET_SIGNALS */
   private static Stream<Arguments> provideTargetSignalBehaviorTestCases() {
     return Stream.of(