com.bennavetta.aeneas.zookeeper.node.ZooKeeper.java Source code

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Here is the source code for com.bennavetta.aeneas.zookeeper.node.ZooKeeper.java

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/**
 * Copyright 2014 Benjamin Navetta
 *
 * 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.bennavetta.aeneas.zookeeper.node;

import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.zeroturnaround.exec.ProcessExecutor;

import com.bennavetta.aeneas.Networking;
import com.bennavetta.aeneas.zookeeper.IdGenerator;
import com.bennavetta.aeneas.zookeeper.ServerRegistry;
import com.bennavetta.aeneas.zookeeper.ZkException;
import com.bennavetta.aeneas.zookeeper.ZkServer;
import com.bennavetta.aeneas.zookeeper.ZkServer.Role;
import com.google.common.base.Preconditions;
import com.google.common.net.HostSpecifier;

/**
 * Runs and watches a ZooKeeper instance
 */
public class ZooKeeper {
    private static final Logger LOG = LoggerFactory.getLogger(ZooKeeper.class);

    private final Path installDir;

    private final ServerRegistry registry;
    private final IdGenerator idGenerator;
    private Configuration configuration;
    private ZkServer server;

    private Process process;

    public ZooKeeper(Path installDir, ServerRegistry registry, IdGenerator idGenerator) {
        this.installDir = Preconditions.checkNotNull(installDir);
        this.registry = Preconditions.checkNotNull(registry);
        this.idGenerator = Preconditions.checkNotNull(idGenerator);

        Preconditions.checkArgument(isValidLocation(), "Must specify a valid ZooKeeper installation");
    }

    public boolean isValidLocation() {
        Path serverBin = installDir.resolve("bin/zkServer.sh");
        return Files.isExecutable(serverBin);
    }

    public void configure() throws IOException, ZkException {
        LOG.info("Configuring ZooKeeper installation in {}", installDir);

        configuration = new Configuration();
        configuration.addDefaults();
        configuration.addFromEnvironment();

        configuration.addServers(registry);
        configuration.setMyId(Util.obtainId(idGenerator, configuration));

        String serverAddress = Networking.getLocalAddress().getHostAddress();

        int peerPort = Integer.parseInt(System.getenv().getOrDefault("PEER_PORT", "2888"));
        int electionPort = Integer.parseInt(System.getenv().getOrDefault("ELECTION_PORT", "3888"));
        int clientPort = Integer.parseInt(System.getenv().getOrDefault("CLIENT_PORT", "2181"));

        server = new ZkServer(configuration.getMyId(), HostSpecifier.fromValid(serverAddress), Role.defaultRole(),
                peerPort, electionPort, clientPort);

        configuration.setDynamic("server." + server.getId(), server.toConnectionSpec());

        Path configRoot = installDir.resolve("conf");
        Files.createDirectories(configRoot);

        configuration.writeId();
        configuration.writeConfiguration(configRoot.resolve("zoo.cfg"), configRoot.resolve("zoo.cfg.dynamic"));

    }

    public void launch() throws ZkException, IOException {
        Preconditions.checkState(process == null, "Already running");
        Preconditions.checkState(configuration != null, "ZooKeeper not configured");

        LOG.info("Starting ZooKeeper with server specification {}", server.toServerSpec());
        process = new ProcessExecutor()
                .command(installDir.resolve("bin/zkServer.sh").toAbsolutePath().toString(), "start-foreground")
                .redirectError(System.err).redirectOutput(System.out).destroyOnExit().start().getProcess();

        registry.register(server);
    }

    public void kill() {
        Preconditions.checkState(process != null, "ZooKeeper not started");
        process.destroy();
    }

    public int waitFor() throws InterruptedException {
        Preconditions.checkState(process != null, "ZooKeeper not started");
        return process.waitFor();
    }

    public void deregister() throws ZkException {
        registry.deregister(server);
    }
}