quyetnd-parlayz/nginx-template-image

Allow Docker environment variables in nginx configuration files

nginx-template-image

This container allows you to use the environment variables set by a Docker link inside of your nginx configuration.

Usage

Mount your configuration to /etc/nginx/sites-templates, preferably read-only. To capture logs, mount a writable directory to /var/log/nginx.

Both HTTP (80) and HTTPS (443) ports are exposed.

For example:

docker run \
  --publish 8080:80 \
  --publish 8443:443 \
  --volume /tmp/nginx-config:/etc/nginx/sites-templates:ro \
  --volume /tmp/nginx-logs:/var/log/nginx \
  --link my-rails-app:rails \
  shepmaster/nginx-template-image

Example nginx config

This is just an example of how to use the templating with a linked container named rails, and should not be treated as an nginx configuration guide!

server {
  listen       80;
  server_name  my-cool-app.dev;

  location / {
    if (!-f $request_filename) {
      proxy_pass   http://${RAILS_PORT_3000_TCP_ADDR}:${RAILS_PORT_3000_TCP_PORT};
      break;
    }
  }
}

Further information

Environment variables

Docker links are communicated via environment variables, but nginx does not easily allow environment variables in configuration files.

To work around this, configuration files mounted at /etc/nginx/sites-templates will be copied to /etc/nginx/sites-enabled. Any file that ends with .tmpl will have variable references like ${FOO} replaced with the corresponding environment variable and have the .tmpl suffix removed.

Only include .conf files

The default nginx configuration includes all files in sites-enabled, which makes it difficult to have supplemental files like SSL keys in the same directory. This container will only load files that end in .conf.