Sub 2 Port

• Route requests to docker containers by host name
• Containers declare their own host name, so the config is decentralized
• The routing table updates automatically in response to docker events
• Ports never have to be exposed, so no more errors about ports already in use
• Multiple containers bound to the same host name are routed round-robin

Why?

The existing reverse proxies for docker have a lot of open issues, because they manage an nginx config and must support its API. I just proxy host names with go. Any other features you need should probably sit in front of or behind this container.

Compose

See the examples folder for docker compose configuration examples.

docker compose -f examples/docker-compose.proxy.yml up -d
docker compose -f examples/docker-compose.nodes.yml up -d

Setup a proxy

Create a shared network for the containers:

docker network create p80

• <name> - Any network name as long as the containers match

Start the sub2port container:

docker run -d -p 80:80 --network p80 -v /var/run/docker.sock:/var/run/docker.sock:ro deckar01/sub2port

• -p <port>:80 - Any host port can be used, but the container listens on 80
• -v <sock>:... - The socket for connecting to the docker API (your system may be different)

Route a host name

Route test.com:80 to port 5555 in a container:

docker run -d -e SUB2PORT=test.com:5555 --network p80 your/image

• -e SUB2PORT=<host>(:port)[,...]
  • A host name is required
  • The container port is optional and defaults to the first open port (does not have to be exposed)
  • Additional hosts can be separated with commas
• --network <name> - The network that is joined determines the host port that is used

Contributing

Prefer publishing a fork to opening a feature request.

Run your fork in production for a while before opening a pull request.

The .github/workflows/docker-publish.yml action publishes on push. Follow these docs to start publishing your changes.