Docker on Ubuntu 16.04 LTS – [Part 04] Docker Compose

Currently, Docker is the most popular and widely used container management system. In most of our enterprise applications nowadays, we do tend to have components running in separate containers. In such an architecture, the “container orchestration” (starting/ shutting down containers and setting up intra-container linkages) is an important factor and the Docker community came up with a solution called Fig, which basically handled this requirement. This uses a single YAML file to orchestrate all your Docker containers and configurations. The popularity of Fig allowed Docker community to plug into its own Docker code base as separate component called “Docker Compose“.

1. Installing Docker Compose

You are required to follow the steps below:

$ sudo curl -o /usr/local/bin/docker-compose -L "https://github.com/docker/compose/releases/download/1.11.2/docker-compose-$(uname -s)-$(uname -m)"

Set the permissions:

$ sudo chmod +x /usr/local/bin/docker-compose

Now check whether it is installed properly:

$ docker-compose -v

2. Running a Container with Docker Compose

Create a directory called “ubuntu” to download an image from GitHub. This will basically download the latest ubuntu distribution as an image to the local.

$ mkdir ubuntu
$ cd ubuntu

Once you do above, create a configuration file (docker-compose.yml) as an guideline to create an image.

docker-compose-test:
  image: ubuntu

Now execute the following:

$ docker-compose up // As an interactive job
$ docker-compose up -d // As a daemon job

The above will read the docker-compose.yml and pull the relevant images and up the respective container.

Pulling docker-compose-test (ubuntu:latest)...
latest: Pulling from library/ubuntu
e0a742c2abfd: Pull complete
486cb8339a27: Pull complete
dc6f0d824617: Pull complete
4f7a5649a30e: Pull complete
672363445ad2: Pull complete
Digest: sha256:84c334414e2bfdcae99509a6add166bbb4fa4041dc3fa6af08046a66fed3005f
Status: Downloaded newer image for ubuntu:latest
Creating ubuntu_docker-compose-test_1
Attaching to ubuntu_docker-compose-test_1
ubuntu_docker-compose-test_1 exited with code 0

Now execute the following to see whether an ubuntu:latest image is downloaded and container is created.

$ docker images
REPOSITORY                    TAG                 IMAGE ID            CREATED             SIZE
ubuntu                        latest              14f60031763d        4 days ago          120 MB

$ docker ps -a
CONTAINER ID        IMAGE                         COMMAND                  CREATED             STATUS                     PORTS                    NAMES
5705871fe7ed        ubuntu                        "/bin/bash"              2 minutes ago       Exited (0) 2 minutes ago                            ubuntu_docker-compose-test_1

References

1. How to install Docker Compose on Ubuntu 16.04 LTS

2. How to install and use Docker Compose on Ubuntu 14.04 LTS

3. How To Configure a Continuous Integration Testing Environment with Docker and Docker Compose on Ubuntu 16.04

4. How To Install WordPress and PhpMyAdmin with Docker Compose on Ubuntu 14.04

4. Docker Compose (Official Web URL)