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 org.apache.kafka.trogdor.common;
  
  import org.apache.kafka.common.utils.Scheduler;
  import org.apache.kafka.common.utils.ThreadUtils;
  import org.apache.kafka.trogdor.agent.Agent;
  import org.apache.kafka.trogdor.agent.AgentClient;
  import org.apache.kafka.trogdor.agent.AgentRestResource;
  import org.apache.kafka.trogdor.basic.BasicNode;
  import org.apache.kafka.trogdor.basic.BasicPlatform;
  import org.apache.kafka.trogdor.basic.BasicTopology;
  import org.apache.kafka.trogdor.coordinator.Coordinator;
  import org.apache.kafka.trogdor.coordinator.CoordinatorClient;
  import org.apache.kafka.trogdor.coordinator.CoordinatorRestResource;
  import org.apache.kafka.trogdor.rest.JsonRestServer;
  
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import java.util.Collections;
  import java.util.HashMap;
  import java.util.Map;
  import java.util.TreeMap;
  import java.util.TreeSet;
  import java.util.concurrent.Callable;
  import java.util.concurrent.Executors;
  import java.util.concurrent.ScheduledExecutorService;
  import java.util.concurrent.TimeUnit;
  import java.util.concurrent.atomic.AtomicReference;
  
  /**
   * MiniTrogdorCluster sets up a local cluster of Trogdor Agents and Coordinators.
   */
  public class MiniTrogdorCluster implements AutoCloseable {
      private static final Logger log = LoggerFactory.getLogger(MiniTrogdorCluster.class);
  
      /**
       * The MiniTrogdorCluster#Builder is used to set up a new MiniTrogdorCluster.
       */
      public static class Builder {
          private final TreeSet<String> agentNames = new TreeSet<>();
  
          private String coordinatorName = null;
  
          private Scheduler scheduler = Scheduler.SYSTEM;
  
          private BasicPlatform.CommandRunner commandRunner =
                  new BasicPlatform.ShellCommandRunner();
  
          private static class NodeData {
              String hostname;
              volatile AgentRestResource agentRestResource = null;
              volatile JsonRestServer agentRestServer = null;
              int agentPort = 0;
  
              volatile JsonRestServer coordinatorRestServer = null;
              int coordinatorPort = 0;
              volatile CoordinatorRestResource coordinatorRestResource = null;
  
              volatile Platform platform = null;
              volatile Agent agent = null;
              volatile Coordinator coordinator = null;
  
              volatile BasicNode node = null;
          }
  
          public Builder() {
          }
  
          /**
           * Set the timekeeper used by this MiniTrogdorCluster.
           */
          public Builder scheduler(Scheduler scheduler) {
              this.scheduler = scheduler;
              return this;
          }
  
          public Builder commandRunner(BasicPlatform.CommandRunner commandRunner) {
              this.commandRunner = commandRunner;
              return this;
          }
  
          /**
           * Add a new trogdor coordinator node to the cluster.
           */
          public Builder addCoordinator(String nodeName) {
              if (coordinatorName != null) {
                  throw new RuntimeException("At most one coordinator is allowed.");
              }
              coordinatorName = nodeName;
              return this;
          }
  
          /**
           * Add a new trogdor agent node to the cluster.
           */
          public Builder addAgent(String nodeName) {
              if (agentNames.contains(nodeName)) {
                  throw new RuntimeException("There is already an agent on node " + nodeName);
              }
              agentNames.add(nodeName);
              return this;
          }
  
          private NodeData getOrCreate(String nodeName, TreeMap<String, NodeData> nodes) {
              NodeData data = nodes.get(nodeName);
              if (data != null)
                  return data;
              data = new NodeData();
              data.hostname = "127.0.0.1";
              nodes.put(nodeName, data);
              return data;
          }
  
          /**
           * Create the MiniTrogdorCluster.
           */
          public MiniTrogdorCluster build() throws Exception {
              log.info("Creating MiniTrogdorCluster with agents: {} and coordinator: {}",
                  String.join(", ", agentNames), coordinatorName);
              TreeMap<String, NodeData> nodes = new TreeMap<>();
              for (String agentName : agentNames) {
                  NodeData node = getOrCreate(agentName, nodes);
                  node.agentRestResource = new AgentRestResource();
                  node.agentRestServer = new JsonRestServer(0);
                  node.agentRestServer.start(node.agentRestResource);
                  node.agentPort = node.agentRestServer.port();
              }
              if (coordinatorName != null) {
                  NodeData node = getOrCreate(coordinatorName, nodes);
                  node.coordinatorRestResource = new CoordinatorRestResource();
                  node.coordinatorRestServer = new JsonRestServer(0);
                  node.coordinatorRestServer.start(node.coordinatorRestResource);
                  node.coordinatorPort = node.coordinatorRestServer.port();
              }
              for (Map.Entry<String, NodeData> entry : nodes.entrySet()) {
                  NodeData node = entry.getValue();
                  HashMap<String, String> config = new HashMap<>();
                  if (node.agentPort != 0) {
                      config.put(Platform.Config.TROGDOR_AGENT_PORT,
                          Integer.toString(node.agentPort));
                  }
                  if (node.coordinatorPort != 0) {
                      config.put(Platform.Config.TROGDOR_COORDINATOR_PORT,
                          Integer.toString(node.coordinatorPort));
                  }
                  node.node = new BasicNode(entry.getKey(), node.hostname, config,
                      Collections.emptySet());
              }
              TreeMap<String, Node> topologyNodes = new TreeMap<>();
              for (Map.Entry<String, NodeData> entry : nodes.entrySet()) {
                  topologyNodes.put(entry.getKey(), entry.getValue().node);
              }
              final BasicTopology topology = new BasicTopology(topologyNodes);
              ScheduledExecutorService executor = Executors.newScheduledThreadPool(1,
                  ThreadUtils.createThreadFactory("MiniTrogdorClusterStartupThread%d", false));
              final AtomicReference<Exception> failure = new AtomicReference<>(null);
              for (final Map.Entry<String, NodeData> entry : nodes.entrySet()) {
                  executor.submit((Callable<Void>) () -> {
                      String nodeName = entry.getKey();
                      try {
                          NodeData node = entry.getValue();
                          node.platform = new BasicPlatform(nodeName, topology, scheduler, commandRunner);
                          if (node.agentRestResource != null) {
                              node.agent = new Agent(node.platform, scheduler, node.agentRestServer,
                                  node.agentRestResource);
                          }
                          if (node.coordinatorRestResource != null) {
                              node.coordinator = new Coordinator(node.platform, scheduler,
                                  node.coordinatorRestServer, node.coordinatorRestResource, 0);
                          }
                      } catch (Exception e) {
                          log.error("Unable to initialize {}", nodeName, e);
                          failure.compareAndSet(null, e);
                      }
                      return null;
                  });
              }
              executor.shutdown();
              executor.awaitTermination(1, TimeUnit.DAYS);
              Exception failureException = failure.get();
              if (failureException != null) {
                  throw failureException;
              }
  
              TreeMap<String, Agent> agents = new TreeMap<>();
              Coordinator coordinator = null;
              for (Map.Entry<String, NodeData> entry : nodes.entrySet()) {
                  NodeData node = entry.getValue();
                  if (node.agent != null) {
                      agents.put(entry.getKey(), node.agent);
                  }
                  if (node.coordinator != null) {
                      coordinator = node.coordinator;
                  }
              }
              return new MiniTrogdorCluster(scheduler, agents, nodes, coordinator);
          }
      }
  
      private final TreeMap<String, Agent> agents;
  
      private final TreeMap<String, Builder.NodeData> nodesByAgent;
  
      private final Coordinator coordinator;
  
      private final Scheduler scheduler;
  
      private MiniTrogdorCluster(Scheduler scheduler,
                                 TreeMap<String, Agent> agents,
                                 TreeMap<String, Builder.NodeData> nodesByAgent,
                                 Coordinator coordinator) {
          this.scheduler = scheduler;
          this.agents = agents;
          this.nodesByAgent = nodesByAgent;
          this.coordinator = coordinator;
      }
  
      public TreeMap<String, Agent> agents() {
          return agents;
      }
  
      public Coordinator coordinator() {
          return coordinator;
      }
  
      public CoordinatorClient coordinatorClient() {
          if (coordinator == null) {
              throw new RuntimeException("No coordinator configured.");
          }
          return new CoordinatorClient.Builder().
              maxTries(10).
              target("localhost", coordinator.port()).
              build();
      }
  
      /**
       * Mimic a restart of a Trogdor agent, essentially cleaning out all of its active workers
       */
      public void restartAgent(String nodeName) {
          if (!agents.containsKey(nodeName)) {
              throw new RuntimeException("There is no agent on node " + nodeName);
          }
          Builder.NodeData node = nodesByAgent.get(nodeName);
          agents.put(nodeName, new Agent(node.platform, scheduler, node.agentRestServer, node.agentRestResource));
      }
  
      public AgentClient agentClient(String nodeName) {
          Agent agent = agents.get(nodeName);
          if (agent == null) {
              throw new RuntimeException("No agent configured on node " + nodeName);
          }
          return new AgentClient.Builder().
              maxTries(10).
              target("localhost", agent.port()).
              build();
      }
  
      @Override
      public void close() throws Exception {
          log.info("Closing MiniTrogdorCluster.");
          if (coordinator != null) {
              coordinator.beginShutdown(false);
          }
          for (Agent agent : agents.values()) {
              agent.beginShutdown();
          }
          for (Agent agent : agents.values()) {
              agent.waitForShutdown();
          }
          if (coordinator != null) {
              coordinator.waitForShutdown();
          }
      }
  }
  