grunt-docker-spawn

This grunt task is inspired by grunt-shell-spawn. It supports instantiation of docker containers using dockerode library.

One of the best use of this task is being able to run complex integration tests against docker containers and then avoid dependencies and setups problematics.

The second best use is to be able to test your application against several backend versions without the need of a hard and long installation/uninstall process. Thus, you only need to pull a specific version then run your backend tests (ie: mongo:2.6.6, mongo:3.0.4, ...).

Install

npm install grunt-docker-spawn

Then add the task in your Gruntfile:

grunt.loadNpmTasks('grunt-docker-spawn')

Examples

The general configuration for a specific container is as follows:

containerName: {
  Image: {String}                    // The repository and name of the image to pull from the dockerhub 
  Cmd: [String]                      // The command which will override the default one
  Name: {String}                     // The name you want the new container to have
  Options: {
    tasks: {
      async: true
    },
    startContainerOptions: {Object}  // Directly forwarded option to the [docker API](https://docs.docker.com/reference/api/docker_remote_api/#full-documentation) 
    matchOuput: {function(chunk)}    // Callback called with the standard outputted data of the container as first argument
  }
}

The containerName object is directly forwarded to dockerode (see docker.createContainer).

Here's how you would launch mongodb(in replication), redis and elasticsearch in which mongodb is linked to elasticsearch (for indexation purpose for instance):

/**
* Ensure that service of containers are finished to start.
*/
function _taskSuccessIfMatch(grunt, regex, info) {
  return function(chunk) {
    var done = grunt.task.current.async();
    var out = '' + chunk;
    var started = regex;
    if (started.test(out)) {
      grunt.log.write(info);
      done(true);
    }
  };
}

...

container: {
  options: {
    machine: {
      host: '192.168.99.100',
      port: 2376,
      ca: fs.readFileSync(process.env.DOCKER_CERT_PATH + '/ca.pem', 'utf-8'),
      cert: fs.readFileSync(process.env.DOCKER_CERT_PATH + '/cert.pem', 'utf-8'),
      key: fs.readFileSync(process.env.DOCKER_CERT_PATH + '/key.pem', 'utf-8'),
      pass: 'mypass'
    }
  },
  redis: {
    Image: 'redis:latest',
    Name: 'redis',
    Options: {
      tasks: {
        async: true
      },
      startContainerOptions: { PortBindings: { '6379/tcp': [{ 'HostPort': '23456' }] } },
      matchOuput: _taskSuccessIfMatch(grunt, /on port/, 'Redis server is started')
    }
  },
  mongodb: {
    Image: 'mongo:latest',
    Cmd: 'mongod --replSet replication --smallfiles --oplogSize 128'.split(' '),
    Name: 'mongodb',
    Options: {
      tasks: {
        async: true
      },
      startContainerOptions: { PortBindings: { '27017/tcp': [{ 'HostPort': '23457' }] }, ExtraHosts: ['mongo:127.0.0.1']},
      matchOuput: _taskSuccessIfMatch(grunt, /connections on port 27017/, 'MongoDB server is started')
    }
  },
  elasticsearch: {
    Image: 'elasticsearch:latest',
    Cmd: ['elasticsearch', '-Des.discovery.zen.ping.multicast.enabled=false'],
    Name: 'elasticsearch',
    Options: {
      tasks: {
        async: true
      },
      startContainerOptions: { PortBindings: { '9200/tcp': [{ 'HostPort': '23458' }] }, Links: ['mongodb:mongo'] },
      matchOuput: _taskSuccessIfMatch(grunt, /started/, 'Elasticsearch server is started')
    }
  },
}

/!\ Do not forget to pull containers first if it is not already done. grunt-docker-spawn uses docker start implementation of dockerode, not docker run /!\

The options to give to instanciate a dockerode client can be set at the task level and selected with the docker argument:

grunt container:redis --docker=machine

This will instanciate the dockerode client with the configuration block defined in options.machine. Check the dockerode documentation for possible values.

Pull needed container

This is how you pull a container. Run this task during setup to initialize your environment. Containers must be available in the Docker Hub community repositories.

grunt container:redis:pull

Run a container

This is how you start a container. Run this task at the beginning of your grunt workflow.

grunt container:redis

Remove a container

This is how you remove a container. Run this task at the end of your grunt workflow.

grunt container:redis container:redis:remove

Containers that are not removed will continue running.

Typical grunt tasks for integration tests

grunt.registerTask('spawn-containers', ['container:redis', 'container:mongodb']);
grunt.registerTask('remove-containers', ['container:redis:remove', 'container:mongodb:remove']);
...
grunt.registerTask('test-integration', ['linters', 'spawn-containers', 'run-integration-tests', 'remove-containers']);

License

MIT License(c) Linagora