Docker Client

This is a Docker client written in Java. It was used in many critical production systems at Spotify until its fork on September 2019.

The docker-client is built and tested against the latest docker-ce major release.

• Download
• Usage Example
• Getting Started
• Prerequisites
• Testing
• Releasing
• User Manual

Download

Download the latest JAR or grab via Maven

<dependency>
  <groupId>org.mandas</groupId>
  <artifactId>docker-client</artifactId>
  <version>LATEST-VERSION</version>
</dependency>

Since multiple JAX-RS client implementations cannot coexist in a flat classpath, you need to choose either one of Jersey or RESTeasy, or create your implementation of DockerClientBuilder for something completely different.

Jersey

For using Jersey, you will have to pull the following dependencies (versions are indicative):

<dependency>
  <groupId>org.glassfish.jersey.core</groupId>
  <artifactId>jersey-client</artifactId>
  <version>3.0.3</version>
</dependency>
<dependency>
  <groupId>org.glassfish.jersey.inject</groupId>
  <artifactId>jersey-hk2</artifactId>
  <version>3.0.3</version>
</dependency>
<dependency>
  <groupId>org.glassfish.jersey.connectors</groupId>
  <artifactId>jersey-apache-connector</artifactId>
  <version>3.0.3</version>
</dependency>
<dependency>
  <groupId>org.glassfish.jersey.media</groupId>
  <artifactId>jersey-media-json-jackson</artifactId>
  <version>3.0.3</version>
</dependency>

RESTeasy

For using RESTeasy, you will have to pull the following dependencies (versions are indicative):

<dependency>
  <groupId>org.jboss.resteasy</groupId>
  <artifactId>resteasy-client</artifactId>
  <version>6.0.0.Final</version>
</dependency>
<dependency>
  <groupId>org.jboss.resteasy</groupId>
  <artifactId>resteasy-core</artifactId>
  <version>6.0.0.Final</version>
</dependency>
<dependency>
  <groupId>com.fasterxml.jackson.jakarta.rs</groupId>
  <artifactId>jackson-jakarta-rs-json-provider</artifactId>
  <version>2.13.1</version>
</dependency>

Usage Example

// Create a client based on DOCKER_HOST and DOCKER_CERT_PATH env vars
final DockerClient docker = new JerseyDockerClientBuilder().fromEnv().build(); // For Jersey
final DockerClient docker = new ResteasyDockerClientBuilder().fromEnv().build(); // For RESTeasy

// Pull an image
docker.pull("busybox");

// Bind container ports to host ports
final String[] ports = {"80", "22"};
final Map<String, List<PortBinding>> portBindings = new HashMap<>();
for (String port : ports) {
    List<PortBinding> hostPorts = new ArrayList<>();
    hostPorts.add(PortBinding.of("0.0.0.0", port));
    portBindings.put(port, hostPorts);
}

// Bind container port 443 to an automatically allocated available host port.
List<PortBinding> randomPort = new ArrayList<>();
randomPort.add(PortBinding.randomPort("0.0.0.0"));
portBindings.put("443", randomPort);

final HostConfig hostConfig = HostConfig.builder().portBindings(portBindings).build();

// Create container with exposed ports
final ContainerConfig containerConfig = ContainerConfig.builder()
    .hostConfig(hostConfig)
    .image("busybox").exposedPorts(ports)
    .cmd("sh", "-c", "while :; do sleep 1; done")
    .build();

final ContainerCreation creation = docker.createContainer(containerConfig);
final String id = creation.id();

// Inspect container
final ContainerInfo info = docker.inspectContainer(id);

// Start container
docker.startContainer(id);

// Exec command inside running container with attached STDOUT and STDERR
final String[] command = {"sh", "-c", "ls"};
final ExecCreation execCreation = docker.execCreate(
    id, command, DockerClient.ExecCreateParam.attachStdout(),
    DockerClient.ExecCreateParam.attachStderr());
final LogStream output = docker.execStart(execCreation.id());
final String execOutput = output.readFully();

// Kill container
docker.killContainer(id);

// Remove container
docker.removeContainer(id);

// Close the docker client
docker.close();

Getting Started

If you're looking for how to use docker-client, see the User Manual. If you're looking for how to build and develop it, keep reading.

Prerequisites

docker-client should be buildable on any platform with Docker 1.6+, JDK8+, and a recent version of Maven 3.

A note on using Docker for Mac

If you are using Docker for Mac and DefaultDockerClient.fromEnv(), it might not be clear what value to use for the DOCKER_HOST environment variable. The value you should use is DOCKER_HOST=unix:///var/run/docker.sock, at least as of version 1.11.1-beta11.

As of version 4.0.8 of docker-client, DefaultDockerClient.fromEnv() uses unix:///var/run/docker.sock on OS X by default.

Testing

If you're running a recent version of docker (>= 1.12), which contains native swarm support, please ensure that you run docker swarm init to initialize the docker swarm.

Make sure Docker daemon is running and that you can do docker ps.

You can run tests on their own with mvn test. Note that the tests start and stop a large number of containers, so the list of containers you see with docker ps -a will start to get pretty long after many test runs. You may find it helpful to occasionally issue docker rm $(docker ps -aq).

Releasing

Commits to the master branch will trigger our continuous integration agent to build the jar and release by uploading to Sonatype. If you are a project maintainer with the necessary credentials, you can also build and release locally by running the below.

mvn clean [-DskipTests -Darguments=-DskipTests] -Dgpg.keyname=<key ID used for signing artifacts> release:prepare release:perform