redirect

adamkdean/redirect is a lightweight companion container for the nginx-proxy. It allows you to easily redirect hostnames, such as in the case of non-www to www.

Versions

• latest, 1.2, 1.2.5 current version
• 1.1, 1.1.0 pre-multihost version (4 April 2021 and before)

Usage (standalone)

The container can be ran as a standalone container, that either redirects all requests or redirects requests based on a per host basis.

Single host

To run as single host mode, simply provide a redirection location and (optionally) a status code and preserve url flag. All requests coming into port 80 in this case will be redirected to the location provided.

docker run \
  --detach \
  --publish 80:80 \
  --env REDIRECT_STATUS_CODE=307 \
  --env REDIRECT_LOCATION="http://www.example.com" \
  --env PRESERVE_URL=true \
  adamkdean/redirect

Multiple hosts

You can also run in multiple host mode by providing a configuration file mapping source hosts to destinations, and (optionally again) providing a status code and preserve url flag override. The default host file location is /etc/redirect/hosts.json but you can override this by setting HOSTS_FILE_PATH.

For example, we could omit the environment variables used in the single host mode, and simply map in a configuration file:

docker run \
  --detach \
  --publish 80:80 \
  --volume $(pwd)/hosts.json:/etc/redirect/hosts.json \
  adamkdean/redirect

where hosts.json is a JSON file containing an array of configuration options:

[
  {
    "source": "example.com",
    "destination": "www.example.com",
    "preserveUrl": true
  },
  {
    "source": "another-example.com",
    "destination": "https://www.another-example.com",
    "statusCode": 303
  }
]

source and destination are required, but preserveUrl (default: false) and statusCode (default: 307) aren't.

If you don't specify the protocol in the destination, it will use the current request protocol. If you're running behind nginx-proxy, this will be http and will add an extra hop in.

Overriding host file path

You can use HOSTS_FILE_PATH to override the host file path like so:

docker run \
  --detach \
  --publish 80:80 \
  --env HOSTS_FILE_PATH=/var/config.json
  --volume $(pwd)/hosts.json:/var/config.json \
  adamkdean/redirect

Usage (nginx-proxy)

It works better if it's used with nginx-proxy/nginx-proxy.

With nginx-proxy you can expose multiple hostnames like below:

version: '2'

services:
  nginx-proxy:
    image: nginx-proxy/nginx-proxy
    ports:
      - 80:80
    volumes:
      - /var/run/docker.sock:/tmp/docker.sock:ro

  example:
    image: example
    environment:
      - VIRTUAL_HOST=example.com,www.example.com

Using adamkdean/redirect, we can ensure that www.example.com is always used.

version: '2'

services:
  nginx-proxy:
    image: nginx-proxy/nginx-proxy
    ports:
      - 80:80
    volumes:
      - /var/run/docker.sock:/tmp/docker.sock:ro

  redirect:
    image: adamkdean/redirect
    environment:
      - VIRTUAL_HOST=example.com
      - REDIRECT_LOCATION="http://www.example.com"
      - REDIRECT_STATUS_CODE=301
      - PRESERVE_URL=true

  example:
    image: example
    environment:
      - VIRTUAL_HOST=www.example.com

Configuration

Single host mode

REDIRECT_LOCATION should be set to the uri that you want to redirect to.

REDIRECT_STATUS_CODE defaults to 307, but you can set it to:

• 301 for Moved Permanently
• 302 for Found
• 303 for See Other
• 307 for Temporary Redirect

PRESERVE_URL can be set to true to enable URLs to be preserve. When set to false, requests will redirect to the location, so https://example.com/posts/24 will redirect to https://www.example.com/. When set to true, it will redirect to https://www.example.com/posts/24 etc.

Multiple host mode

HOSTS_FILE_PATH defaults to /etc/redirect/hosts.json but this can be overridden. See above.