Dockerode: Streamlining Docker Management using Node.js

In this blog we will see how to manage docker containers using Node js.

Installing Dockerode

npm install dockerode

1. Create and Starting a container

Import Dockerode and create a Docker client instance

const Docker = require('dockerode');
const docker = new Docker();

Specify the port mapping configuration for your container.

const portBindings = {
  '3000/tcp': [{ HostPort: '8000' }]
};

In the above example, we are mapping port 3000 inside the container to port 8000 on the host.

Pull the docker image from docker hub

    docker.pull('wordpress', function (err, stream) {
    //...
    docker.modem.followProgress(stream, onFinished, onProgress);

    function onFinished(err, output) {

    }
    function onProgress(event) {

    }
});

Now to create and start a container with the specified port mapping:

const container = await docker.createContainer({
  Image: 'your-image-name',
  AttachStdin: false,
  AttachStdout: true,
  AttachStderr: true,
  Tty: true,
  ExposedPorts: { '3000/tcp': {} },
  HostConfig: {
    PortBindings: portBindings
  }
});//creates the container

await container.start(); //starts the container

Replace the ‘your-image-name’ with the name of the image you want to run. At this point your container will start running in the specified port.

Starting A Wordpress Container using Dockerode

const Docker = require('dockerode');
const docker = new Docker();

const portBindings = {
    '80/tcp': [{ HostPort: '8080' }]
};

const pullContainer = async()=>{
    await docker.pull('wordpress', function (err, stream) {
        //...
        docker.modem.followProgress(stream, onFinished, onProgress);
    
        function onFinished(err, output) {
            createContainer();
        }
        function onProgress(event) {
            if (event.status === 'Downloading') {
                process.stdout.clearLine(0);
                process.stdout.cursorTo(0);
                process.stdout.write(event.progress);
    
            }else{
                process.stdout.clearLine(0);
                process.stdout.cursorTo(0);
                process.stdout.write(event.status+"\n")
            }
        }
    });
}

const createContainer = async () => {
    const container = await docker.createContainer({
        Image: 'wordpress',
        AttachStdin: false,
        AttachStdout: true,
        AttachStderr: true,
        Tty: true,
        ExposedPorts: { '80/tcp': {} },
        HostConfig: {
          PortBindings: portBindings
        },
        name: 'wordpress-site'
      });

      await container.start();
}


pullContainer();

Using docker ps command we can see that wordpress is running successfully

Wordpress is started successfully on port 8080

2. List all the containers in the system

const Docker = require('dockerode');
const docker = new Docker();
docker.listContainers((err, containers) => {
    if (err) {
      console.log('Error:', err);
    } else {
      console.log('Container Information:', containers);
    }
  });

The listContainers method returns an array of container objects, where each object represents a container running on the Docker host. The objects contain information such as container ID, names, image, status, ports, and more.

3. Stop all the running containers

const Docker = require('dockerode');
const docker = new Docker();
docker.listContainers(function (err, containers) {
  containers.forEach(function (containerInfo) {
    docker.getContainer(containerInfo.Id).stop(cb);
  });
});

Using getContainer method we can get the container by providing the container ID. using stop we can stop the container.