MetricsUtils.java

/*
 * Copyright 2023 Google LLC
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 *    * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *    * Redistributions in binary form must reproduce the above
 * copyright notice, this list of conditions and the following disclaimer
 * in the documentation and/or other materials provided with the
 * distribution.
 *
 *    * Neither the name of Google LLC nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

package com.google.auth.oauth2;

import com.google.api.client.http.HttpRequest;
import com.google.auth.CredentialTypeForMetrics;
import java.io.IOException;
import java.io.InputStream;
import java.util.Properties;

class MetricsUtils {
  static final String API_CLIENT_HEADER = "x-goog-api-client";
  static final String CRED_TYPE = "cred-type";
  static final String AUTH_REQUEST_TYPE = "auth-request-type";
  private static final String authLibraryVersion = getAuthLibraryVersion();
  private static final String javaLanguageVersion = System.getProperty("java.version");

  /**
   * Gets the x-goog-api-client header value for the current Java language version and the auth
   * library version.
   *
   * @return the header value.
   */
  static String getLanguageAndAuthLibraryVersions() {
    return String.format("gl-java/%s auth/%s", javaLanguageVersion, authLibraryVersion);
  }

  private static String getAuthLibraryVersion() {
    // Attempt to read the library's version from a properties file generated during the build.
    // This value should be read and cached for later use.
    String version = "unknown-version";
    try (InputStream inputStream =
        MetricsUtils.class.getResourceAsStream(
            "/com/google/auth/oauth2/google-auth-library.properties")) {
      if (inputStream != null) {
        final Properties properties = new Properties();
        properties.load(inputStream);
        version = properties.getProperty("google-auth-library.version");
      }
    } catch (IOException e) {
      // Ignore.
    }
    return version;
  }

  public enum RequestType {
    ACCESS_TOKEN_REQUEST("at"),
    ID_TOKEN_REQUEST("it"),
    METADATA_SERVER_PING("mds"),
    UNTRACKED("untracked");

    private final String label;

    private RequestType(String label) {
      this.label = label;
    }

    public String getLabel() {
      return label;
    }
  }

  /**
   * Formulates metrics header string. Header string takes format: ���gl-java/JAVA_VERSION
   * auth/LIB_VERSION auth-request-type/REQUEST_TYPE cred-type/CREDENTIAL_TYPE���. "auth-request-type"
   * and "cred-type" can be omitted.
   *
   * @param requestType Auth request type to be specified in metrics, omit when {@code
   *     RequestType.UNTRACKED}
   * @param credentialTypeForMetrics Credential type to be included in metrics string, omit when
   *     {@code CredentialTypeForMetrics.DO_NOT_SEND}
   * @return metrics header string to send
   */
  static String getGoogleCredentialsMetricsHeader(
      RequestType requestType, CredentialTypeForMetrics credentialTypeForMetrics) {
    StringBuilder stringBuilder =
        new StringBuilder(MetricsUtils.getLanguageAndAuthLibraryVersions());
    if (requestType != RequestType.UNTRACKED) {
      stringBuilder.append(String.format(" %s/%s", AUTH_REQUEST_TYPE, requestType.getLabel()));
    }
    if (credentialTypeForMetrics != CredentialTypeForMetrics.DO_NOT_SEND) {
      stringBuilder.append(String.format(" %s/%s", CRED_TYPE, credentialTypeForMetrics.getLabel()));
    }
    return stringBuilder.toString();
  }

  static void setMetricsHeader(HttpRequest request, String metricsHeader) {
    request.getHeaders().set(MetricsUtils.API_CLIENT_HEADER, metricsHeader);
  }
}