content: /**
   * 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
   * <p>
   * http://www.apache.org/licenses/LICENSE-2.0
   * <p>
   * 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.atlas.ha;
  
  import org.apache.atlas.security.SecurityProperties;
  import org.apache.commons.configuration.Configuration;
  import org.apache.commons.lang.StringUtils;
  
  import java.util.ArrayList;
  import java.util.List;
  import java.util.Objects;
  
  /**
   * A wrapper for getting configuration entries related to HighAvailability.
   */
  public final class HAConfiguration {
      public static final String ATLAS_SERVER_ZK_ROOT_DEFAULT               = "/apache_atlas";
      public static final String ATLAS_SERVER_HA_PREFIX                     = "atlas.server.ha.";
      public static final String ZOOKEEPER_PREFIX                           = "zookeeper.";
      public static final String ATLAS_SERVER_HA_ZK_ROOT_KEY                = ATLAS_SERVER_HA_PREFIX + ZOOKEEPER_PREFIX + "zkroot";
      public static final String ATLAS_SERVER_HA_ENABLED_KEY                = ATLAS_SERVER_HA_PREFIX + "enabled";
      public static final String ATLAS_SERVER_ADDRESS_PREFIX                = "atlas.server.address.";
      public static final String ATLAS_SERVER_IDS                           = "atlas.server.ids";
      public static final String HA_ZOOKEEPER_CONNECT                       = ATLAS_SERVER_HA_PREFIX + ZOOKEEPER_PREFIX + "connect";
      public static final int    DEFAULT_ZOOKEEPER_CONNECT_SLEEPTIME_MILLIS = 1000;
      public static final String HA_ZOOKEEPER_RETRY_SLEEPTIME_MILLIS        = ATLAS_SERVER_HA_PREFIX + ZOOKEEPER_PREFIX + "retry.sleeptime.ms";
      public static final String HA_ZOOKEEPER_NUM_RETRIES                   = ATLAS_SERVER_HA_PREFIX + ZOOKEEPER_PREFIX + "num.retries";
      public static final int    DEFAULT_ZOOKEEPER_CONNECT_NUM_RETRIES      = 3;
      public static final String HA_ZOOKEEPER_SESSION_TIMEOUT_MS            = ATLAS_SERVER_HA_PREFIX + ZOOKEEPER_PREFIX + "session.timeout.ms";
      public static final int    DEFAULT_ZOOKEEPER_SESSION_TIMEOUT_MILLIS   = 20000;
      public static final String HA_ZOOKEEPER_ACL                           = ATLAS_SERVER_HA_PREFIX + ZOOKEEPER_PREFIX + "acl";
      public static final String HA_ZOOKEEPER_AUTH                          = ATLAS_SERVER_HA_PREFIX + ZOOKEEPER_PREFIX + "auth";
  
      private HAConfiguration() {
          // to block instantiation
      }
  
      /**
       * Return whether HA is enabled or not.
       * @param configuration underlying configuration instance
       * @return
       */
      public static boolean isHAEnabled(Configuration configuration) {
          boolean ret;
  
          if (configuration.containsKey(HAConfiguration.ATLAS_SERVER_HA_ENABLED_KEY)) {
              ret = configuration.getBoolean(ATLAS_SERVER_HA_ENABLED_KEY);
          } else {
              String[] ids = configuration.getStringArray(HAConfiguration.ATLAS_SERVER_IDS);
  
              ret = ids != null && ids.length > 1;
          }
  
          return ret;
      }
  
      /**
       * Get the web server address that a server instance with the passed ID is bound to.
       *
       * This method uses the property {@link SecurityProperties#TLS_ENABLED} to determine whether
       * the URL is http or https.
       *
       * @param configuration underlying configuration
       * @param serverId serverId whose host:port property is picked to build the web server address.
       * @return
       */
      public static String getBoundAddressForId(Configuration configuration, String serverId) {
          String  hostPort = configuration.getString(ATLAS_SERVER_ADDRESS_PREFIX + serverId);
          boolean isSecure = configuration.getBoolean(SecurityProperties.TLS_ENABLED);
          String  protocol = (isSecure) ? "https://" : "http://";
  
          return protocol + hostPort;
      }
  
      public static List<String> getServerInstances(Configuration configuration) {
          String[]     serverIds       = configuration.getStringArray(ATLAS_SERVER_IDS);
          List<String> serverInstances = new ArrayList<>(serverIds.length);
  
          for (String serverId : serverIds) {
              serverInstances.add(getBoundAddressForId(configuration, serverId));
          }
  
          return serverInstances;
      }
  
      public static ZookeeperProperties getZookeeperProperties(Configuration configuration) {
          String[] zkServers;
  
          if (configuration.containsKey(HA_ZOOKEEPER_CONNECT)) {
              zkServers = configuration.getStringArray(HA_ZOOKEEPER_CONNECT);
          } else {
              zkServers = configuration.getStringArray("atlas.kafka." + ZOOKEEPER_PREFIX + "connect");
          }
  
          String zkRoot                 = configuration.getString(ATLAS_SERVER_HA_ZK_ROOT_KEY, ATLAS_SERVER_ZK_ROOT_DEFAULT);
          int    retriesSleepTimeMillis = configuration.getInt(HA_ZOOKEEPER_RETRY_SLEEPTIME_MILLIS, DEFAULT_ZOOKEEPER_CONNECT_SLEEPTIME_MILLIS);
          int    numRetries             = configuration.getInt(HA_ZOOKEEPER_NUM_RETRIES, DEFAULT_ZOOKEEPER_CONNECT_NUM_RETRIES);
          int    sessionTimeout         = configuration.getInt(HA_ZOOKEEPER_SESSION_TIMEOUT_MS, DEFAULT_ZOOKEEPER_SESSION_TIMEOUT_MILLIS);
          String acl                    = configuration.getString(HA_ZOOKEEPER_ACL);
          String auth                   = configuration.getString(HA_ZOOKEEPER_AUTH);
  
          return new ZookeeperProperties(StringUtils.join(zkServers, ','), zkRoot, retriesSleepTimeMillis, numRetries, sessionTimeout, acl, auth);
      }
  
      /**
       * A collection of Zookeeper specific configuration that is used by High Availability code.
       */
      public static class ZookeeperProperties {
          private final String connectString;
          private final String zkRoot;
          private final int    retriesSleepTimeMillis;
          private final int    numRetries;
          private final int    sessionTimeout;
          private final String acl;
          private final String auth;
  
          public ZookeeperProperties(String connectString, String zkRoot, int retriesSleepTimeMillis, int numRetries, int sessionTimeout, String acl, String auth) {
              this.connectString          = connectString;
              this.zkRoot                 = zkRoot;
              this.retriesSleepTimeMillis = retriesSleepTimeMillis;
              this.numRetries             = numRetries;
              this.sessionTimeout         = sessionTimeout;
              this.acl                    = acl;
              this.auth                   = auth;
          }
  
          public String getConnectString() {
              return connectString;
          }
  
          public int getRetriesSleepTimeMillis() {
              return retriesSleepTimeMillis;
          }
  
          public int getNumRetries() {
              return numRetries;
          }
  
          public int getSessionTimeout() {
              return sessionTimeout;
          }
  
          public String getAcl() {
              return acl;
          }
  
          public String getAuth() {
              return auth;
          }
  
          public String getZkRoot() {
              return zkRoot;
          }
  
          @Override
          public int hashCode() {
              return Objects.hash(connectString, zkRoot, retriesSleepTimeMillis, numRetries, sessionTimeout, acl, auth);
          }
  
          @Override
          public boolean equals(Object o) {
              if (this == o) {
                  return true;
              } else if (o == null || getClass() != o.getClass()) {
                  return false;
              }
  
              ZookeeperProperties that = (ZookeeperProperties) o;
  
              return retriesSleepTimeMillis == that.retriesSleepTimeMillis &&
                      numRetries == that.numRetries &&
                      sessionTimeout == that.sessionTimeout &&
                      Objects.equals(connectString, that.connectString) &&
                      Objects.equals(zkRoot, that.zkRoot) &&
                      Objects.equals(acl, that.acl) &&
                      Objects.equals(auth, that.auth);
          }
  
          public boolean hasAcl() {
              return getAcl() != null;
          }
  
          public boolean hasAuth() {
              return getAuth() != null;
          }
      }
  }
  