com.bennavetta.aeneas.mesos.slave.docker.Docker.java Source code

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Here is the source code for com.bennavetta.aeneas.mesos.slave.docker.Docker.java

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/**
 * Copyright 2015 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.mesos.slave.docker;

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

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.google.common.base.Throwables;
import com.google.common.collect.ImmutableList;

/**
 * Support for Mesos' Docker containerizer
 */
public final class Docker {
    private static final Logger LOG = LoggerFactory.getLogger(Docker.class);

    private Docker() {
    }

    private static boolean socketExists() {
        return Files.exists(Paths.get("/var/run/docker.sock"));
    }

    /**
     * If necessary, attempt to launch a Docker daemon.
     * @return {@code true} if a Docker daemon exists or was started, {@code false} if no Docker daemon could be obtained
     */
    public static boolean startDocker() {
        if (socketExists()) {
            LOG.debug("Found existing Docker socket");
        } else {
            try {
                LOG.debug("Launching Docker daemon");
                Daemon.launchDaemon(ImmutableList.of());

                LOG.debug("Waiting for daemon to start");
                Thread.sleep(15000);
            } catch (IOException e) {
                LOG.error("Unable to start Docker daemon", e);
                return false;
            } catch (InterruptedException e) {
                throw Throwables.propagate(e);
            }
        }
        return true;
    }
}