Nginx reverse proxy, Docker and a Raspberry Pi

If you read my previous post you should know that fourteenislands.io is served by a Nginx web server (Docker) running on a Raspberry Pi. But what started as a sandbox environment to host a few static pages is getting busier everyday and I, among other things, needed to host a couple of RESTful web APIs on that Raspberry Pi (on a different domain name).

Automated Nginx reverse proxy for Docker

I’ll spare you with the details as to why a reverse proxy and how to automatically generate reverse proxy configuration when ‘backend’ Docker containers are started and stopped and suggest you read this interesting post by Jason Wilder.

Jason’s nginx-proxy targets the X86 architecture and cannot be used as is on a Raspberry Pi. You could use rpi-nginx-proxy instead which is the equivalent I published for the ARM architecture.

So, let’s start a proxy.

From a terminal on your RPi open your favorite text editor and save the following as docker-compose.yml

# docker-compose.yml for the nginx reverse proxy
nginx-proxy:
  container_name: nginx-proxy
  image: lroguet/rpi-nginx-proxy:latest
  ports:
    - "80:80"
  volumes:
    - /var/run/docker.sock:/tmp/docker.sock:ro

Start the Nginx reverse proxy ‘frontend’ container with the following command

$ docker-compose run -d --service-ports nginx-proxy

You don’t really need Docker Compose here and could run the same ‘frontend’ container with that one-liner:

$ docker run -d -p 80:80 -v /var/run/docker.sock:/tmp/docker.sock:ro lroguet/rpi-nginx-proxy

That was easy, wasn’t it?

Serving a domain (fourteenislands.io for example)

Now that the reverse proxy is up and running we can just start whatever ‘backend’ container we want to serve content for a specific domain (note the VIRTUAL_HOST environment variable in the docker-compose.yml file below).

Head back to your RPi terminal and favorite text editor: save the following as docker-compose.yml

# docker-compose.yml for lab.fourteenislands.io
# Assumes your generated/copied static site is in /home/pi/volumes/nginx
web:
  container_name: nginx
  image: lroguet/rpi-nginx:latest
  environment:
    - VIRTUAL_HOST=fourteenislands.io
  volumes:
    - /home/pi/volumes/nginx:/var/www/html

Start the Nginx ‘backend’ container with the following command

$ docker-compose run -d --service-ports web

Using Docker Compose makes more sense here but is obviously not required.

Starting a ‘backend’ container triggers a Docker start event, the reverse proxy configuration is generated and the ‘frontend’ Nginx reloaded.

When a ‘backend’ container is stopped or dies, a Docker die/stop event is triggered, the reverse proxy configuration is generated and the ‘frontend’ Nginx reloaded.

As always, have fun and if you have any questions, please leave a comment.

Update. fourteenislands.io is not currently served from a Raspberry Pi but from an Amazon S3 bucket.