docker-nginx-auto-ssl

Docker image for automatic generation of SSL certs using Let's encrypt and Open Resty, with reasonable SSL settings. You can specify allowed domains and simple proxies using ENV variables, and easily override nginx.conf to your needs.

This is possible thanks to OpenResty and lua-resty-auto-ssl.

Image status: used in production. Some backward-compatible changes may be added in the future.

Usage

Basic usage:

docker run -d \
  -p 80:80 \
  -p 443:443 \
  valian/docker-nginx-auto-ssl

Created certs are kept in /etc/resty-auto-ssl directory. It's volume by default, but you may want to mount it to some directory on the host.

Available configuration options:

Variable	Example	Description
ALLOWED_DOMAINS	(www|api).example.com, example.com, ([a-z]+.)?example.com	lua pattern of allowed domains. Internally, we're using string.match. By default we accept all domains
DIFFIE_HELLMAN	true	Force regeneration of dhparam.pem. If not specified, default one is used.
SITES	db.com=localhost:5432; *.app.com=localhost:8080, _=localhost:8080	Shortcut for defining multiple proxies, in form of domain1=endpoint1; domain2=endpoint2. Default template for proxy is here. Name _ means default server, just like in nginx configuration
FORCE_HTTPS	true, false	If true, automatically adds location to resty-server-http.conf redirecting traffic from http to https. true by default.
LETSENCRYPT_URL	https://acme-v01.api.letsencrypt.org/directory, https://acme-staging.api.letsencrypt.org/directory	Let's Encrypt server URL to use

If you want to proxy multiple sites (probably the most common case, that's why I've made it possible to achieve without custom configuration):

docker run -d \
  --name nginx-auto-ssl \
  --restart on-failure \
  -p 80:80 \
  -p 443:443 \
  -e ALLOWED_DOMAINS=example.com \
  -e SITES='example.com=localhost:5432;*.example.com=localhost:8080' \
  valian/docker-nginx-auto-ssl

All options:

docker run -d \
  --name nginx-auto-ssl \
  --restart on-failure \
  -p 80:80 \
  -p 443:443 \
  -e ALLOWED_DOMAINS=example.com \
  -e SITES='example.com=localhost:5432;*.example.com=localhost:8080' \
  -e DIFFIE_HELLMAN=true \
  -v ssl-data:/etc/resty-auto-ssl \
  valian/docker-nginx-auto-ssl

Customization

Includes from /etc/nginx/conf.d/*.conf

Additional server blocks are automatically loaded from /etc/nginx/conf.d/*.conf. If you want to provide your own configuration, you can either use volumes or create custom image.

Example server configuration (for example, named server.conf)

server {
  listen 443 ssl default_server;
  
  # remember about this line!
  include resty-server-https.conf;

  location / {
    proxy_pass http://app;
  }
  
  location /api {
    proxy_pass http://api;
  }
}

Volumes way

# instead of $PWD, use directory with your custom configurations
docker run -d \
  --name nginx-auto-ssl \
  --restart on-failure \
  -p 80:80 \
  -p 443:443 \
  -v $PWD:/etc/nginx/conf.d
  valian/docker-nginx-auto-ssl

Custom image way

FROM valian/docker-nginx-auto-ssl

# instead of . use directory with your configurations
COPY . /etc/nginx/conf.d

docker build -t docker-nginx-auto-ssl .
docker run [YOUR_OPTIONS] docker-nginx-auto-ssl

Using $SITES with your own template

You have to override /usr/local/openresty/nginx/conf/server-proxy.conf either using volume or custom image. Basic templating is implemented for variables $SERVER_NAME and $SERVER_ENDPOINT.

Example template:

server {
  listen 443 ssl;
  server_name $SERVER_NAME;

  include resty-server-https.conf;

  location / {
    proxy_pass http://$SERVER_ENDPOINT;
  }
}

Your own nginx.conf

If you have custom requirements and other customization options are not enough, you can easily provide your own configuration.

Example Dockerfile:

FROM valian/docker-nginx-auto-ssl

COPY nginx.conf /usr/local/openresty/nginx/conf/

Minimal working nginx.conf:

events {
  worker_connections 1024;
}

http {
  
  # required
  include resty-http.conf;

  server {
    listen 443 ssl;
    
    # required
    include resty-server-https.conf;
    
    # you should add your own locations here    
  }

  server {
    listen 80 default_server;
    
    # required
    include resty-server-http.conf;
  }
}

Minimal nginx.conf with support for $SITES and conf.d includes

events {
  worker_connections 1024;
}

http {

  include resty-http.conf;

  server {
    listen 80 default_server;
    include resty-server-http.conf;
  }
  
  # you can insert your blocks here or inside conf.d
  
  include /etc/nginx/conf.d/*.conf;
}

Build and run it using

docker build -t docker-nginx-auto-ssl .
docker run [YOUR_OPTIONS] docker-nginx-auto-ssl

CHANGELOG

• 29-05-2017 - Fixed duplicate redirect location after container restart #2
• 19-12-2017 - Support for $SITES variable
• 2-12-2017 - Dropped HSTS by default
• 25-11-2017 - Initial release

LICENCE

MIT