Total Pageviews

Thursday, 3 March 2016

Automated nginx proxy for Docker containers using docker-gen


nginx-proxy sets up a container running nginx and docker-gen. docker-gen generates reverse proxy configs for nginx and reloads nginx when containers are started and stopped.
See Automated Nginx Reverse Proxy for Docker for why you might want to use this.

Usage

To run it:
$ docker run -d -p 80:80 -v /var/run/docker.sock:/tmp/docker.sock:ro 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  ...
The containers being proxied must expose the port to be proxied, either by using the EXPOSE directive in their Dockerfile or by using the --expose flag to docker run or docker create.
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.

Docker-compose

Currently this does not work with the new v2 syntax of docker-compose (due to not being compatible with the new network overlay see #304). It does work when using the old docker-composer syntax.

Multiple Ports

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.

Multiple Hosts

If you need to support multiple virtual hosts for a container, you can separate each entry with commas. For example, foo.bar.com,baz.bar.com,bar.com and each host will be setup the same.

Wildcard Hosts

You can also use wildcards at the beginning and the end of host name, like *.bar.com or foo.bar.*. Or even a regular expression, which can be very useful in conjunction with a wildcard DNS service like xip.io, using ~^foo\.bar\..*\.xip\.io will match foo.bar.127.0.0.1.xip.iofoo.bar.10.0.2.2.xip.io and all other given IPs. More information about this topic can be found in the nginx documentation about server_names.

SSL Backends

If you would like to connect to your backend using HTTPS instead of HTTP, set VIRTUAL_PROTO=https on the backend container.

Default Host

To set the default host for nginx use the env var DEFAULT_HOST=foo.bar.com for example
$ docker run -d -p 80:80 -e DEFAULT_HOST=foo.bar.com -v /var/run/docker.sock:/tmp/docker.sock:ro jwilder/nginx-proxy

Separate Containers

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:ro \
    -v $(pwd):/etc/docker-gen/templates \
    -t jwilder/docker-gen -notify-sighup nginx -watch -only-exposed /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  ...

SSL Support

SSL is supported using single host, wildcard and SNI certificates using naming conventions for certificates or optionally specifying a cert name (for SNI) as an environment variable.
To enable SSL:
$ docker run -d -p 80:80 -p 443:443 -v /path/to/certs:/etc/nginx/certs -v /var/run/docker.sock:/tmp/docker.sock:ro jwilder/nginx-proxy
The contents of /path/to/certs should contain the certificates and private keys for any virtual hosts in use. The certificate and keys should be named after the virtual host with a .crt and .key extension. For example, a container with VIRTUAL_HOST=foo.bar.com should have a foo.bar.com.crt and foo.bar.com.key file in the certs directory.

Diffie-Hellman Groups

If you have Diffie-Hellman groups enabled, the files should be named after the virtual host with a dhparam suffix and .pemextension. For example, a container with VIRTUAL_HOST=foo.bar.com should have a foo.bar.com.dhparam.pem file in the certs directory.

Wildcard Certificates

Wildcard certificates and keys should be named after the domain name with a .crt and .key extension. For example VIRTUAL_HOST=foo.bar.com would use cert name bar.com.crt and bar.com.key.

SNI

If your certificate(s) supports multiple domain names, you can start a container with CERT_NAME=<name> to identify the certificate to be used. For example, a certificate for *.foo.com and *.bar.com could be named shared.crt and shared.key. A container running with VIRTUAL_HOST=foo.bar.com and CERT_NAME=shared will then use this shared cert.

How SSL Support Works

The SSL cipher configuration is based on mozilla nginx intermediate profile which should provide compatibility with clients back to Firefox 1, Chrome 1, IE 7, Opera 5, Safari 1, Windows XP IE8, Android 2.3, Java 7. The configuration also enables HSTS, and SSL session caches.
The behavior for the proxy when port 80 and 443 are exposed is as follows:
  • If a container has a usable cert, port 80 will redirect to 443 for that container so that HTTPS is always preferred when available.
  • If the container does not have a usable cert, a 503 will be returned.
Note that in the latter case, a browser may get an connection error as no certificate is available to establish a connection. A self-signed or generic cert named default.crt and default.key will allow a client browser to make a SSL connection (likely w/ a warning) and subsequently receive a 503.

Basic Authentication Support

In order to be able to secure your virtual host, you have to create a file named as its equivalent VIRTUAL_HOST variable on directory /etc/nginx/htpasswd/$VIRTUAL_HOST
$ docker run -d -p 80:80 -p 443:443 \
    -v /path/to/htpasswd:/etc/nginx/htpasswd \
    -v /path/to/certs:/etc/nginx/certs \
    -v /var/run/docker.sock:/tmp/docker.sock:ro \
    jwilder/nginx-proxy
You'll need apache2-utils on the machine where you plan to create the htpasswd file. Follow these instructions

Custom Nginx Configuration

If you need to configure Nginx beyond what is possible using environment variables, you can provide custom configuration files on either a proxy-wide or per-VIRTUAL_HOST basis.

Replacing default proxy settings

If you want to replace the default proxy settings for the nginx container, add a configuration file at /etc/nginx/proxy.conf. A file with the default settings would look like this:
# HTTP 1.1 support
proxy_http_version 1.1;
proxy_buffering off;
proxy_set_header Host $http_host;
proxy_set_header Upgrade $http_upgrade;
proxy_set_header Connection $proxy_connection;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header X-Forwarded-Proto $proxy_x_forwarded_proto;
NOTE: If you provide this file it will replace the defaults; you may want to check the .tmpl file to make sure you have all of the needed options.

Proxy-wide

To add settings on a proxy-wide basis, add your configuration file under /etc/nginx/conf.d using a name ending in .conf.
This can be done in a derived image by creating the file in a RUN command or by COPYing the file into conf.d:
FROM jwilder/nginx-proxy
RUN { \
      echo 'server_tokens off;'; \
      echo 'client_max_body_size 100m;'; \
    } > /etc/nginx/conf.d/my_proxy.conf
Or it can be done by mounting in your custom configuration in your docker run command:
$ docker run -d -p 80:80 -p 443:443 -v /path/to/my_proxy.conf:/etc/nginx/conf.d/my_proxy.conf:ro -v /var/run/docker.sock:/tmp/docker.sock:ro jwilder/nginx-proxy

Per-VIRTUAL_HOST

To add settings on a per-VIRTUAL_HOST basis, add your configuration file under /etc/nginx/vhost.d. Unlike in the proxy-wide case, which allows multiple config files with any name ending in .conf, the per-VIRTUAL_HOST file must be named exactly after the VIRTUAL_HOST.
In order to allow virtual hosts to be dynamically configured as backends are added and removed, it makes the most sense to mount an external directory as /etc/nginx/vhost.d as opposed to using derived images or mounting individual configuration files.
For example, if you have a virtual host named app.example.com, you could provide a custom configuration for that host as follows:
$ docker run -d -p 80:80 -p 443:443 -v /path/to/vhost.d:/etc/nginx/vhost.d:ro -v /var/run/docker.sock:/tmp/docker.sock:ro jwilder/nginx-proxy
$ { echo 'server_tokens off;'; echo 'client_max_body_size 100m;'; } > /path/to/vhost.d/app.example.com
If you are using multiple hostnames for a single container (e.g. VIRTUAL_HOST=example.com,www.example.com), the virtual host configuration file must exist for each hostname. If you would like to use the same configuration for multiple virtual host names, you can use a symlink:
$ { echo 'server_tokens off;'; echo 'client_max_body_size 100m;'; } > /path/to/vhost.d/www.example.com
$ ln -s /path/to/vhost.d/www.example.com /path/to/vhost.d/example.com

Per-VIRTUAL_HOST default configuration

If you want most of your virtual hosts to use a default single configuration and then override on a few specific ones, add those settings to the /etc/nginx/vhost.d/default file. This file will be used on any virtual host which does not have a /etc/nginx/vhost.d/{VIRTUAL_HOST} file associated with it.

Per-VIRTUAL_HOST location configuration

To add settings to the "location" block on a per-VIRTUAL_HOST basis, add your configuration file under /etc/nginx/vhost.d just like the previous section except with the suffix _location.
For example, if you have a virtual host named app.example.com and you have configured a proxy_cache my-cache in another custom file, you could tell it to use a proxy cache as follows:
$ docker run -d -p 80:80 -p 443:443 -v /path/to/vhost.d:/etc/nginx/vhost.d:ro -v /var/run/docker.sock:/tmp/docker.sock:ro jwilder/nginx-proxy
$ { echo 'proxy_cache my-cache;'; echo 'proxy_cache_valid  200 302  60m;'; echo 'proxy_cache_valid  404 1m;' } > /path/to/vhost.d/app.example.com_location
If you are using multiple hostnames for a single container (e.g. VIRTUAL_HOST=example.com,www.example.com), the virtual host configuration file must exist for each hostname. If you would like to use the same configuration for multiple virtual host names, you can use a symlink:
$ { echo 'proxy_cache my-cache;'; echo 'proxy_cache_valid  200 302  60m;'; echo 'proxy_cache_valid  404 1m;' } > /path/to/vhost.d/app.example.com_location
$ ln -s /path/to/vhost.d/www.example.com /path/to/vhost.d/example.com

Per-VIRTUAL_HOST location default configuration

If you want most of your virtual hosts to use a default single location block configuration and then override on a few specific ones, add those settings to the /etc/nginx/vhost.d/default_location file. This file will be used on any virtual host which does not have a /etc/nginx/vhost.d/{VIRTUAL_HOST} file associated with it.

Contributing

Before submitting pull requests or issues, please check github to make sure an existing issue or pull request is not already open.

Running Tests Locally

To run tests, you'll need to install bats 0.4.0.
make test
from  https://github.com/jwilder/nginx-proxy