[OpenTelemetry] Add gcp otel auth extension

buildSrc/src/main/groovy/org/apache/beam/gradle/BeamModulePlugin.groovy

@@ -869,6 +869,8 @@ class BeamModulePlugin implements Plugin<Project> {
         opentelemetry_sdk                           : "io.opentelemetry:opentelemetry-sdk", // opentelemetry-bom sets version
         opentelemetry_exporter_otlp                 : "io.opentelemetry:opentelemetry-exporter-otlp", // opentelemetry-bom sets version
         opentelemetry_extension_autoconfigure       : "io.opentelemetry:opentelemetry-sdk-extension-autoconfigure", // opentelemetry-bom sets version
+        opentelemetry_proto                         : "io.opentelemetry.proto:opentelemetry-proto:$opentelemetry_version-alpha",
+        opentelemetry_sdk_testing                   : "io.opentelemetry:opentelemetry-sdk-testing:$opentelemetry_version",
         postgres                                    : "org.postgresql:postgresql:$postgres_version",
         protobuf_java                               : "com.google.protobuf:protobuf-java:$protobuf_version",
         protobuf_java_util                          : "com.google.protobuf:protobuf-java-util:$protobuf_version",

sdks/java/extensions/opentelemetry-gcp-auth-extension/build.gradle

@@ -0,0 +1,49 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you 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.
+ */
+
+plugins { id 'org.apache.beam.module' }
+applyJavaNature(
+  automaticModuleName: 'org.apache.beam.sdk.extensions.opentelemetry.gcp.auth',
+)
+
+description = "Apache Beam :: SDKs :: Java :: Extensions :: OpenTelemetry GCP Auth"
+ext.summary = "OpenTelemetry extension that provides GCP authentication support for OTLP exporters."
+
+dependencies {
+  implementation enforcedPlatform(library.java.google_cloud_platform_libraries_bom)
+  implementation platform(library.java.opentelemetry_bom)
+  implementation library.java.google_auth_library_oauth2_http
+  implementation library.java.vendored_guava_32_1_2_jre
+  compileOnly library.java.opentelemetry_api
+  compileOnly library.java.opentelemetry_extension_autoconfigure
+  compileOnly library.java.opentelemetry_exporter_otlp
+
+  testImplementation library.java.junit
+  testImplementation library.java.mockito_core
+  testImplementation library.java.mockito_inline
+  testImplementation library.java.jupiter_api
+  testImplementation library.java.jupiter_params
+  testRuntimeOnly library.java.jupiter_engine
+  testImplementation library.java.truth
+  testImplementation library.java.opentelemetry_api
+  testImplementation library.java.opentelemetry_sdk
+  testImplementation library.java.opentelemetry_exporter_otlp
+  testImplementation library.java.opentelemetry_sdk_testing
+  testImplementation library.java.opentelemetry_extension_autoconfigure
+}
+test { useJUnitPlatform() }

sdks/java/extensions/opentelemetry-gcp-auth-extension/src/main/java/org/apache/beam/sdk/extensions/opentelemetry/gcp/auth/ConfigurableOption.java

@@ -0,0 +1,163 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you 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 org.apache.beam.sdk.extensions.opentelemetry.gcp.auth;
+
+import static java.util.Locale.ROOT;
+
+import io.opentelemetry.sdk.autoconfigure.spi.ConfigProperties;
+import io.opentelemetry.sdk.autoconfigure.spi.ConfigurationException;
+import java.util.Optional;
+import java.util.function.Supplier;
+
+/**
+ * An enum representing configurable options for a GCP Authentication Extension. Each option has a
+ * user-readable name and can be configured using environment variables or system properties.
+ *
+ * <p>Copied from
+ * https://github.com/open-telemetry/opentelemetry-java-contrib/blob/main/gcp-auth-extension/src/main/java/io/opentelemetry/contrib/gcp/auth/ConfigurableOption.java
+ */
+enum ConfigurableOption {
+  /**
+   * Represents the Google Cloud Project ID option. Can be configured using the environment variable
+   * `GOOGLE_CLOUD_PROJECT` or the system property `google.cloud.project`.
+   */
+  GOOGLE_CLOUD_PROJECT("Google Cloud Project ID"),
+
+  /**
+   * Represents the Google Cloud Quota Project ID option. Can be configured using the environment
+   * variable `GOOGLE_CLOUD_QUOTA_PROJECT` or the system property `google.cloud.quota.project`. The
+   * quota project is the project that is used for quota management and billing for the API usage.
+   *
+   * <p>The environment variable name is selected to be consistent with the <a
+   * href="https://cloud.google.com/docs/quotas/set-quota-project">official GCP client
+   * libraries</a>.
+   */
+  GOOGLE_CLOUD_QUOTA_PROJECT("Google Cloud Quota Project ID"),
+
+  /**
+   * Specifies a comma-separated list of OpenTelemetry signals for which this authentication
+   * extension should be active. The authentication mechanisms provided by this extension will only
+   * be applied to the listed signals. If not set, {@code all} is assumed to be set which means
+   * authentication is enabled for all supported signals.
+   *
+   * <p>Valid signal values are:
+   *
+   * <ul>
+   *   <li>{@code metrics} - Enables authentication for metric exports.
+   *   <li>{@code traces} - Enables authentication for trace exports.
+   *   <li>{@code all} - Enables authentication for all exports.
+   * </ul>
+   *
+   * <p>The values are case-sensitive. Whitespace around commas and values is ignored. Can be
+   * configured using the environment variable `GOOGLE_OTEL_AUTH_TARGET_SIGNALS` or the system
+   * property `google.otel.auth.target.signals`.
+   */
+  GOOGLE_OTEL_AUTH_TARGET_SIGNALS("Target Signals for Google Authentication Extension");
+
+  private final String userReadableName;
+  private final String environmentVariableName;
+  private final String systemPropertyName;
+
+  ConfigurableOption(String userReadableName) {
+    this.userReadableName = userReadableName;
+    this.environmentVariableName = this.name();
+    this.systemPropertyName = this.environmentVariableName.toLowerCase(ROOT).replace('_', '.');
+  }
+
+  /**
+   * Returns the environment variable name associated with this option.
+   *
+   * @return the environment variable name (e.g., GOOGLE_CLOUD_PROJECT)
+   */
+  String getEnvironmentVariable() {
+    return this.environmentVariableName;
+  }
+
+  /**
+   * Returns the system property name associated with this option.
+   *
+   * @return the system property name (e.g., google.cloud.project)
+   */
+  String getSystemProperty() {
+    return this.systemPropertyName;
+  }
+
+  /**
+   * Returns the user readable name associated with this option.
+   *
+   * @return the user readable name (e.g., "Google Cloud Quota Project ID")
+   */
+  String getUserReadableName() {
+    return this.userReadableName;
+  }
+
+  /**
+   * Retrieves the configured value for this option. This method checks the environment variable
+   * first and then the system property.
+   *
+   * @return The configured value as a string, or throws an exception if not configured.
+   * @throws ConfigurationException if neither the environment variable nor the system property is
+   *     set.
+   */
+  String getConfiguredValue(ConfigProperties configProperties) {
+    String configuredValue = configProperties.getString(this.getSystemProperty());
+    if (configuredValue != null && !configuredValue.isEmpty()) {
+      return configuredValue;
+    } else {
+      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",
+              this.userReadableName, this.getEnvironmentVariable(), this.getSystemProperty()));
+    }
+  }
+
+  /**
+   * Retrieves the value for this option, prioritizing environment variables and system properties.
+   * If neither an environment variable nor a system property is set for this option, the provided
+   * fallback function is used to determine the value.
+   *
+   * @param fallback A {@link Supplier} that provides the default value for the option when it is
+   *     not explicitly configured via an environment variable or system property.
+   * @return The configured value for the option, obtained from the environment variable, system
+   *     property, or the fallback function, in that order of precedence.
+   */
+  String getConfiguredValueWithFallback(
+      ConfigProperties configProperties, Supplier<String> fallback) {
+    try {
+      return this.getConfiguredValue(configProperties);
+    } catch (ConfigurationException e) {
+      return fallback.get();
+    }
+  }
+
+  /**
+   * Retrieves the value for this option, prioritizing environment variables before system
+   * properties. If neither an environment variable nor a system property is set for this option,
+   * then an empty {@link Optional} is returned.
+   *
+   * @return The configured value for the option, if set, obtained from the environment variable,
+   *     system property, or empty {@link Optional}, in that order of precedence.
+   */
+  Optional<String> getConfiguredValueAsOptional(ConfigProperties configProperties) {
+    try {
+      return Optional.of(this.getConfiguredValue(configProperties));
+    } catch (ConfigurationException e) {
+      return Optional.empty();
+    }
+  }
+}