Container Nursery

Written in Node.js, this application acts as a HTTP reverse proxy and stops Docker containers which haven't been accessed recently and starts them again when a new request comes in. ContainerNursery also makes sure there are no more active WebSocket connections before stopping the container.

To improve the user experience a loading page is presented, which automatically reloads when the containers webserver is ready.

The application listens on port 80 by default for HTTP traffic and uses the socket at /var/run/docker.sock to connect to the docker daemon.

You can find the changelog in the CHANGELOG.md file.

Demo

https://user-images.githubusercontent.com/2771251/132314400-817971fd-b364-4c78-9fed-650138960530.mp4

Installation

I heavily recommend using another reverse proxy in front of ContainerNursery (for HTTPS, caching, etc.) pointing to your configured listening port (default 80).

I also recommend running this application in a Docker container. Pull the latest image using:

docker pull ghcr.io/itsecholot/containernursery:latest

More information about the available tags and versions can be found on the GitHub packages page.

Example

docker run \
  --name='ContainerNursery' \
  -v /var/run/docker.sock:/var/run/docker.sock \
  -v /mnt/ContainerNursery/config:/usr/src/app/config \
  ghcr.io/itsecholot/containernursery:latest

Configuration

To configure the proxy, edit the config.yml file in the config directory. The configuration file is automatically reloaded by the application when changes are made. If no config.yml file is found an empty one is automatically created on application start.

The following top-level properties can be configured:

The virtual hosts the proxy should handle can be configured by adding an object to the proxyHosts key.

The following properties are required:

The following properties are optional:

Example Configuration

proxyListeningPort: 80
proxyHosts:
  - domain: handbrake.yourdomain.io
    containerName: handbrake
    displayName: Handbrake
    proxyHost: localhost
    proxyPort: 5800
    timeoutSeconds: 15
    stopOnTimeoutIfCpuUsageBelow: 50
    proxyUseCustomMethod: GET
  - domain:
      - wordpress.yourdomain.io
      - wordpress.otherdomain.io
    containerName:
      - wordpress
      - mariadb
    proxyHost: wordpress
    proxyPort: 3000
    proxyUseHttps: true
    timeoutSeconds: 1800

Now point your existing reverse proxy for the hosts you configured in the previous step to the ContainerNursery IP/Domain Name on port 80.

Important: If you use the (otherwise) excellent NginxProxyManager disable the caching for proxy hosts that are routed through ContainerNursery. Because the built-in caching config sadly also caches 404s this will lead to NginxProxyManager caching error messages while your app container is starting up and then refusing to serve the real .js/.css file once the startup is complete.

Example Configuration for NginxProxyManager

Environment Variables

Additionally to the configuration done in the congif.yml file, there are a few settings which can only be configured by using environment variables.