Docker

Docker is an open-source project that automates the deployment of applications inside software containers. Quote of features from docker web page:

Docker containers wrap up a piece of software in a complete filesystem that contains everything it needs to run: code, runtime, system tools, system libraries – anything you can install on a server. This guarantees that it will always run the same, regardless of the environment it is running in.

Install docker

Note: For this install, I will be using Ubuntu 16.04 LTS (Xenial Xerus). Docker requires a 64-bit version of Ubuntu as well as a kernel version equal to or greater than 3.10. My system satisfies both requirements.

• Setup the docker repo to install from:

$ sudo apt-get update -y
$ sudo apt-key adv --keyserver hkp://p80.pool.sks-keyservers.net:80 --recv-keys 58118E89F3A912897C070ADBF76221572C52609D
$ echo "deb https://apt.dockerproject.org/repo ubuntu-xenial main" | sudo tee /etc/apt/sources.list.d/docker.list
$ sudo apt-get update -y

Make sure you are about to install from the Docker repo instead of the default Ubuntu 16.04 repo:

$ apt-cache policy docker-engine

The output of the above command show look something like the following:

docker-engine:
  Installed: (none)
  Candidate: 1.11.2-0~xenial
  Version table:
     1.11.2-0~xenial 500
        500 https://apt.dockerproject.org/repo ubuntu-xenial/main amd64 Packages
     1.11.1-0~xenial 500
        500 https://apt.dockerproject.org/repo ubuntu-xenial/main amd64 Packages
     1.11.0-0~xenial 500
        500 https://apt.dockerproject.org/repo ubuntu-xenial/main amd64 Packages

• Install docker:

$ sudo apt-get install -y docker-engine

• Check on the status of docker:

$ sudo systemctl status docker

● docker.service - Docker Application Container Engine
   Loaded: loaded (/lib/systemd/system/docker.service; enabled; vendor preset: enabled)
   Active: active (running) since Tue 2016-07-12 12:31:08 PDT; 6s ago
     Docs: https://docs.docker.com
 Main PID: 3392 (docker)
   CGroup: /system.slice/docker.service
           ├─3392 /usr/bin/docker daemon -H fd://
           └─3411 docker-containerd -l /var/run/docker/libcontainerd/docker-containerd.sock --runtime docker-runc --start-timeout 2m

• Make sure the docker service automatically starts after a machine reboot:

$ sudo systemctl enable docker

• Execute docker without `sudo`:

$ sudo usermod -aG docker $(whoami)

Log out and log back in to use docker without `sudo`.

• Check that docker has been successfully installed and configured:

$ docker run hello-world

...
This message shows that your installation appears to be working correctly.
...

External links

• Official website