ExperimentalHostHelper.java

/*
 * Copyright 2020 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.example.spanner;

import com.google.cloud.spanner.SpannerOptions;
import com.google.common.base.Strings;

public class ExperimentalHostHelper {
  private static final String EXPERIMENTAL_HOST = "spanner.experimental_host";
  private static final String USE_PLAIN_TEXT = "spanner.use_plain_text";
  private static final String USE_MTLS = "spanner.mtls";
  private static final String CLIENT_CERT_PATH = "spanner.client_cert_path";
  private static final String CLIENT_CERT_KEY_PATH = "spanner.client_cert_key_path";

  /**
   * Checks whether an experimental host is being used. This is done by checking if the
   * {@code spanner.experimental_host} system property is set.
   *
   * @return true if an experimental host is being used. Returns false otherwise.
   */
  public static boolean isExperimentalHost() {
    return !Strings.isNullOrEmpty(System.getProperty(EXPERIMENTAL_HOST));
  }

  public static boolean isMtlsSetup() {
    return Boolean.getBoolean(USE_MTLS);
  }

  public static void setExperimentalHostSpannerOptions(SpannerOptions.Builder builder) {
    if (!isExperimentalHost()) {
      throw new IllegalStateException(EXPERIMENTAL_HOST + " must be set to use this method");
    }
    String experimentalHost = System.getProperty(EXPERIMENTAL_HOST, "");
    boolean usePlainText = Boolean.getBoolean(USE_PLAIN_TEXT);
    builder.setExperimentalHost(experimentalHost);
    builder.setBuiltInMetricsEnabled(false);
    if (usePlainText) {
      builder.usePlainText();
    }
    if (isMtlsSetup()) {
      String clientCertificate = System.getProperty(CLIENT_CERT_PATH, "");
      String clientKey = System.getProperty(CLIENT_CERT_KEY_PATH, "");
      if (Strings.isNullOrEmpty(clientCertificate)) {
        throw new IllegalArgumentException(CLIENT_CERT_PATH + " must be set when mTLS is enabled");
      }
      if (Strings.isNullOrEmpty(clientKey)) {
        throw new IllegalArgumentException(CLIENT_CERT_KEY_PATH + " must be set when mTLS is enabled");
      }
      builder.useClientCert(clientCertificate, clientKey);
    }
  }
}