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
   *
   * 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 backtype.storm.security;
  
  import backtype.storm.daemon.Shutdownable;
  
  import java.util.Map;
  
  /**
   * Nimbus auto credential plugin that will be called on nimbus host during submit topology option. User can specify a list of implementation using config key
   * nimbus.autocredential.plugins.classes.
   */
  public interface INimbusCredentialPlugin extends Shutdownable {
  
      /**
       * this method will be called when nimbus initializes.
       * 
       * @param conf
       */
      void prepare(Map conf);
  
      /**
       * Method that will be called on nimbus as part of submit topology. This plugin will be called at least once during the submit Topology action. It will be
       * not be called during activate instead the credentials return by this method will be merged with the other credentials in the topology and stored in
       * zookeeper.
       * 
       * @param credentials credentials map where more credentials will be added.
       * @param conf topology configuration
       * @return
       */
      void populateCredentials(Map<String, String> credentials, Map conf);
  }
  