Auto-portforward (apf)

A handy tool to automatically set up proxies that expose the remote container's listening ports back to the local machine. Just like kubectl portforward or docker run -p LOCAL:REMOTE, but automatically discover and update the ports to be forwarded on the fly. apf can create listening ports in the container and forward them back as well.

I often find myself forgetting to add -p option when testing a docker image or missing to expose some other ports. Now I don't need to worry about that, I just run the following commands:

$ docker run -d --name redis redis

$ apf redis

*  ==> : Forwarding local listening ports to (==>) remote ports
*  <== : Forwarding to local ports from (<==) remote listening ports (use -r option)

Forwarding: [6379 ==> 6379]

apf will update the port list on the fly. So if you login to the container and start other server listening on different ports, it will dynamically update the local listeners.

For Kubernetes (hey, if you haven't heard of telepresence , please give it a try, it's way cooler than this project.):

$ kubectl run --image redis redis

$ apf -k default/redis
Forwarding: [6379 ==> 6379]

For Podman:

$ podman run --name redis docker.io/library/redis:latest

$ apf -p redis
Forwarding: [6379 ==> 6379]

Installation

First of all, apf requires a working docker / kubectl client setup, the client can connect to either local docker daemon / k8s cluster or remote.

You can either download the binary from the release artifacts or build it yourself.

# MacOS (Intel)
curl -L -O https://github.com/ruoshan/autoportforward/releases/latest/download/apf-mac
chmod +x apf-mac
mv apf-mac /usr/local/bin/apf

# MacOS (ARM)
curl -L -O https://github.com/ruoshan/autoportforward/releases/latest/download/apf-mac-arm64
chmod +x apf-mac-arm64
mv apf-mac-arm64 /usr/local/bin/apf

# Linux
curl -L -O https://github.com/ruoshan/autoportforward/releases/latest/download/apf-linux-x64
chmod +x apf-linux-x64
mv apf-linux-x64 /usr/local/bin/apf

To manually build it, clone the repo and run the build.sh script.

Usage

Expose all the listening ports in the container back to the local machine

# Docker
apf {container ID / name}

# Kubernetes
apf -k {namespace}/{pod name}

# Podman
apf -p {podman container ID / name}

Also expose local ports (8080,9090) to the container

# Docker
apf -r 8080,9090  {container ID / name}

# Kubernetes
apf -r 8080,9090 -k {namespace}/{pod name}

# Podman
apf -r 8080,9090 -p {podman container ID / name}

Limitations

• Currently, apf only supports containers of the same CPU arch of your host machine. For other arch, you can do a custom build by tweaking the build.sh script.
• For Kubernetes, the container must have tar installed.
• If the container is run with readonly rootfs, apf won't work. (apf needs to copy a guest agent into the container)

Tips

1. apf does not come with shell completion, but here is what I do to make it more handy:

# `brew install fzf`
alias ap='docker ps | grep -v "^CONTAINER ID" | fzf | awk "{print \$1}" | xargs -n 1 apf'