docker_host_port_forward.bash

#!/usr/bin/env bash
set -Eeuxo pipefail

# Usage example: ./docker_host_port_forward.bash start 4000 14000
#                ./docker_host_port_forward.bash stop  4000 14000

# TODO: alpine/socat is not necessarily trustworthy.  Find a better base image
#       or build ourselves.
# TODO: If socat is not installed, it fails silently.  We should let user know
#       if it failed and why it failed.

case "$1" in
   "start")
        start-stop-daemon -obm -p "/var/run/m19g_docker_host_port_forward_$2_$3" --start --startas \
            "$(which socat)" TCP-LISTEN:"$2",fork,reuseaddr "EXEC:docker run --net=host --rm -i alpine/socat \"STDIO TCP-CONNECT:127.0.0.1:$3\""
   ;;
   "stop")
        start-stop-daemon -om  -p "/var/run/m19g_docker_host_port_forward_$2_$3" --stop  --startas \
            "$(which socat)" TCP-LISTEN:"$2",fork,reuseaddr "EXEC:docker run --net=host --rm -i alpine/socat \"STDIO TCP-CONNECT:127.0.0.1:$3\""
   ;;
   *)
       echo "Usage: start [local_port] [docker_host_port]"
       echo "       stop  [local_port] [docker_host_port]"
       exit 1
   ;;
esac

Maybe we can provide a wrapper that does port-forwarding behind k3d kubectl or k3dctl. It doesn't seem too bad to me. microk8s also provides their own wrapper for example.

https://microk8s.io/docs/

microk8s.kubectl get nodes
microk8s.kubectl get services

It seems I have made a mistake in leaving the above comment. My intention was to leave it under the thread of your review.

Thanks for the detailed explanation. They make sense to me. I am not familiar with the mirok8s project and it seems to be a good idea to take a look their design choices as well. Thanks for the pointers.

k3d project can definitely benefit more from your insights, suggestions and code contributions. Looking forward to them in the future.