Server Deployments on Ubuntu with Docker and Supervisor

We'll use supervisor to manage docker containers in our host machine.

Installation

Install Docker and Supervisor via apt. There's a mirror that contains the latest version of docker.

$ sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys 36A1D7869245C8950F966E92D8576A8BA88D21E9

$ sudo sh -c "echo deb https://get.docker.io/ubuntu docker main\
> /etc/apt/sources.list.d/docker.list"

$ sudo apt-get update
$ sudo apt-get install lxc-docker

Here's a complete guide on how to install docker: https://docs.docker.com/installation/ubuntulinux/

Configuring Docker

Update /etc/default/docker and add the following line:

DOCKER_OPTS="-r=false $DOCKER_OPTS"

This stops docker from auto-restarting containers that failed to start. We'll let supervisor manage that for us.

Supervisor Configuration

Write a supervisor configuration for your application and save it in /etc/supervisor/conf.d/.

Here's an example supervisor configuration for your app

[program:myapp]
autorestart=true
autostart=true
command=docker run --name myapp -a stdout -a stderr --rm=true -p 3000:3000 -v /home/ubuntu/deploy:/app -e PORT=3000 me/myapp python server.py

Command Arguments Used

1. --name sets our container's name.
2. -a stdout -a stderr gets the internal process' stream so we can use supervisor to log.
3. Stopping a container does not delete it. --rm removes the container once it's stopped.
4. -p 3000:3000 forwards our host's port 3000 to our container's port 3000.
5. You can set environment variables inside the container. ie. -e PORT=3000