nginx-proxy sets up a container running nginx and docker-gen. docker-gen generate reverse proxy configs for nginx and reloads nginx when containers they are started and stopped.
See Automated Nginx Reverse Proxy for Docker for why you might want to use this.
To run it:
$ docker run -d -p 80:80 -v /var/run/docker.sock:/tmp/docker.sock jwilder/nginx-proxy
Then start any containers you want proxied with an env var VIRTUAL_HOST=subdomain.youdomain.com
$ docker run -e VIRTUAL_HOST=foo.bar.com ...
Provided your DNS is setup to forward foo.bar.com to the a host running nginx-proxy, the request will be routed to a container with the VIRTUAL_HOST env var set.
If your container exposes multiple ports, nginx-proxy will default to the service running on port 80. If you need to specify a different port, you can set a VIRTUAL_PORT env var to select a different one. If your container only exposes one port and it has a VIRTUAL_HOST env var set, that port will be selected.
If you need to support multipe virtual hosts for a container, you can separate each enty with commas. For example, foo.bar.com,baz.bar.com,bar.com and each host will be setup the same.
nginx-proxy can also be run as two separate containers using the jwilder/docker-gen image and the official nginx image.
You may want to do this to prevent having the docker socket bound to a publicly exposed container service.
To run nginx proxy as a separate container you'll need to have nginx.tmpl on your host system.
First start nginx with a volume:
$ docker run -d -p 80:80 --name nginx -v /tmp/nginx:/etc/nginx/conf.d -t nginx
Then start the docker-gen container with the shared volume and template:
$ docker run --volumes-from nginx \
-v /var/run/docker.sock:/tmp/docker.sock \
-v $(pwd):/etc/docker-gen/templates \
-t docker-gen -notify-sighup nginx -watch --only-published /etc/docker-gen/templates/nginx.tmpl /etc/nginx/conf.d/default.conf
Finally, start your containers with VIRTUAL_HOST environment variables.
$ docker run -e VIRTUAL_HOST=foo.bar.com ...