NGinX Docker Rancher auto discovery and automatic reverse proxy for containers

This project adds the ability for Rancher clusters to automatically deploy and configure Nginx for all containers exposing an environment variable named VIRTUAL_HOST.

What it does

Let's say you have a Rancher cluster like the one below:

What you see is an example of the full ELK stack with Hadoop.

You see there are few web interfaces, Kopf and Kibana namely.

What this container does is to create the necessary configuration files for Nginx so that you can address the web interfaces by a typical URL like:

https://kopf.service.<domain_name>

Every option available in Nginx can be modified, including the default vhost template.

There is no possibility at the moment to specialize on a per vhost basis as the point is to have a common configuration across the whole cluster.

This package also handles Nginx where it can serve as a load balancer for TCP/UDP as this is required for applications like Logstash in this very example. This is done using Nginx streams.

Configuration sample

This is the most complete configuration deployed to date on a production environment.

Docker-compose

Affinity here is useful when you plan to use specific (tagged) hosts to expose Web interfaces.

This should be a functionality that will appear in the next versions of Rancher, but in the meantime it works 😄

nginx:
  image: oorabona/nginx-rancher-rp
  labels:
    io.rancher.container.network: true
    io.rancher.container.hostname_override: container_name
    io.rancher.scheduler.affinity:host_label: ${affinity}
  environment:
    RANCHER_METADATA_HOST: ${rancher_host}
    IP_FIELD: ${ip_field_policy}
  ports:
   - "80:80"
   - "443:443"
  volumes:
    - '${base_dir}/certs:/etc/nginx/certs:ro'
    - '${base_dir}/nginx/vhosts.d:/etc/nginx/vhosts.d:ro'
    - '${base_dir}/nginx/html:/usr/share/nginx/html:ro'

Rancher-compose

The above variables are context given by Rancher Catalog like in the example below.

.catalog:
  name: "nginx-reverse-proxy"
  version: "latest-custom"
  description: "Automatic reverse proxy for your Web containers deployed in Rancher"
  questions:
    - variable: base_dir
      description: "Base directory for configuration files."
      label: "Base directory"
      type: "string"
      required: true
      default: "/srv"
    - variable: affinity
      label: "Rancher scheduler affinity, based on hosts labels!"
      description: "Can be any key=value pair..."
      type: "string"
      required: true
      default: "fq.label=value"
    - variable: rancher_host
      label: "Rancher Server Hostname"
      description: "External URL of Rancher host"
      type: "string"
      required: true
      default: "http://rancher:8080"
    - variable: ip_field_policy
      label: "Select which field in data.fields metadata should be the source of remote IP"
      description: "Select among the supported possibilities"
      type: "enum"
      default: primaryIpAddress
      options:
        - dockerIp
        - primaryIpAddress

Setup

You can setup the container using either options:

Rebuilding from Dockerfile

You will need to run the ONBUILD enabled Dockerfile.

FROM oorabona/nginx-rancher-rp:onbuild

With nginx.conf and nginx-default-vhost.conf files in the same directory.

$ mkdir nginx-foo-rp
$ cd nginx-foo-rp
$ ls
Dockerfile nginx.conf nginx-default-vhost.conf
$ docker build -t foo/nginx-foo-rp .

Mounting volumes