dataflow.examples.DockerClientExample.java Source code

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Here is the source code for dataflow.examples.DockerClientExample.java

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/**
 * 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 dataflow.examples;

import java.io.File;
import java.io.IOException;
import java.io.PrintStream;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;

import org.apache.commons.io.FilenameUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.spotify.docker.client.DefaultDockerClient;
import com.spotify.docker.client.DockerClient;
import com.spotify.docker.client.DockerException;

import dataflow.docker.DockerProcessBuilder;

/**
 * A simple example of using the spotify docker client.
 */
public class DockerClientExample {
    private static final Logger logger = LoggerFactory.getLogger(DockerClientExample.class.getName());

    static private String createLocalTempDir() {
        SimpleDateFormat formatter = new SimpleDateFormat("yyyyMMdd-HHmmss");
        Date date = new Date();
        String timestamp = formatter.format(date);

        // TODO(jlewi): Is there a java function we could use?
        File temp = null;
        try {
            temp = File.createTempFile("temp-" + timestamp + "-", "");
        } catch (IOException exception) {
            logger.error("Could not create temporary file.", exception);
            System.exit(-1);
        }

        if (!(temp.delete())) {
            throw new RuntimeException("Could not delete temp file: " + temp.getAbsolutePath());
        }

        if (!(temp.mkdir())) {
            throw new RuntimeException("Could not create temp directory: " + temp.getAbsolutePath());
        }
        return temp.getPath();
    }

    public static void main(String[] args) throws IOException, DockerException, InterruptedException {
        String localTempDir = createLocalTempDir();
        String dockerAddress = "unix:///var/run/docker.sock";
        String dockerImage = "ubuntu:latest";
        DockerClient dockerClient = new DefaultDockerClient(dockerAddress);
        String localInput = FilenameUtils.concat(localTempDir, "file_on_host.txt");

        PrintStream stream = new PrintStream(localInput);
        stream.append("\nHello from the host machine.\n");
        stream.close();

        // Run a simple command in the container to demonstrate we can read the
        // file mounted from the host.
        ArrayList<String> command = new ArrayList<String>();
        command.add("cat");
        command.add("/mounted/file_on_host.txt");

        DockerProcessBuilder builder = new DockerProcessBuilder(command, dockerClient);
        builder.addVolumeMapping(localTempDir, "/mounted");
        builder.setImage(dockerImage);

        // Start and run the container.
        builder.start();
    }
}