RPI changes

This dockerfile comes from the official nginx repo and has been a bit changed to support resin/rpi-raspbian:jessie based image. You can pull this image from docker running into a rasberry PI with:

docker pull alssi/rpi-nginx

What is nginx?

Nginx (pronounced "engine-x") is an open source reverse proxy server for HTTP, HTTPS, SMTP, POP3, and IMAP protocols, as well as a load balancer, HTTP cache, and a web server (origin server). The nginx project started with a strong focus on high concurrency, high performance and low memory usage. It is licensed under the 2-clause BSD-like license and it runs on Linux, BSD variants, Mac OS X, Solaris, AIX, HP-UX, as well as on other *nix flavors. It also has a proof of concept port for Microsoft Windows.

wikipedia.org/wiki/Nginx

How to use this image

Hosting some simple static content

$ docker run --name some-nginx -v /some/content:/usr/share/nginx/html:ro -d alssi/rpi-nginx

Alternatively, a simple Dockerfile can be used to generate a new image that includes the necessary content (which is a much cleaner solution than the bind mount above):

FROM alssi/rpi-nginx
COPY static-html-directory /usr/share/nginx/html

Place this file in the same directory as your directory of content ("static-html-directory"), run docker build -t some-content-nginx ., then start your container:

$ docker run --name some-nginx -d some-content-nginx

Exposing external port

$ docker run --name some-nginx -d -p 8080:80 some-content-nginx

Then you can hit http://localhost:8080 or http://host-ip:8080 in your browser.

Complex configuration

$ docker run --name my-custom-nginx-container -v /host/path/nginx.conf:/etc/nginx/nginx.conf:ro -d alssi/rpi-nginx

For information on the syntax of the nginx configuration files, see the official documentation (specifically the Beginner's Guide).

If you wish to adapt the default configuration, use something like the following to copy it from a running nginx container:

$ docker run --name tmp-nginx-container -d alssi/rpi-nginx
$ docker cp tmp-nginx-container:/etc/nginx/nginx.conf /host/path/nginx.conf
$ docker rm -f tmp-nginx-container

This can also be accomplished more cleanly using a simple Dockerfile (in /host/path/):

FROM alssi/rpi-nginx
COPY nginx.conf /etc/nginx/nginx.conf

If you add a custom CMD in the Dockerfile, be sure to include -g daemon off; in the CMD in order for nginx to stay in the foreground, so that Docker can track the process properly (otherwise your container will stop immediately after starting)!

Then build the image with docker build -t custom-nginx . and run it as follows:

$ docker run --name my-custom-nginx-container -d custom-nginx

Using environment variables in nginx configuration

Out-of-the-box, nginx doesn't support environment variables inside most configuration blocks. But envsubst may be used as a workaround if you need to generate your nginx configuration dynamically before nginx starts.

Here is an example using docker-compose.yml:

web:
  image: alssi/rpi-nginx
  volumes:
   - ./mysite.template:/etc/nginx/conf.d/mysite.template
  ports:
   - "8080:80"
  environment:
   - NGINX_HOST=foobar.com
   - NGINX_PORT=80
  command: /bin/bash -c "envsubst < /etc/nginx/conf.d/mysite.template > /etc/nginx/conf.d/default.conf && nginx -g 'daemon off;'"

The mysite.template file may then contain variable references like this:

listen ${NGINX_PORT};

Running nginx in debug mode

Images since version 1.9.8 come with nginx-debug binary that produces verbose output when using higher log levels. It can be used with simple CMD substitution:

$ docker run --name my-nginx -v /host/path/nginx.conf:/etc/nginx/nginx.conf:ro -d alssi/rpi-nginx nginx-debug -g 'daemon off;'

Similar configuration in docker-compose.yml may look like this:

web:
  image: alssi/rpi-nginx
  volumes:
    - ./nginx.conf:/etc/nginx/nginx.conf:ro
  command: [nginx-debug, '-g', 'daemon off;']

Monitoring nginx with Amplify

Amplify is a free monitoring tool that can be used to monitor microservice architectures based on nginx. Amplify is developed and maintained by the company behind the nginx software.

With Amplify it is possible to collect and aggregate metrics across containers, and present a coherent set of visualizations of the key performance data, such as active connections or requests per second. It is also easy to quickly check for any performance degradations, traffic anomalies, and get a deeper insight into the nginx configuration in general.

In order to use Amplify, a small Python-based agent software (Amplify Agent) should be installed inside the container.

For more information about Amplify, please check the official documentation here.

Image Variants

At the moment, only debian jessie is supported.