Port expose error when running in dind-rootless

[emilytrau]

Starting a container that exposes a port inside a dind-rootless causes an error.

docker: Error response from daemon: driver failed programming external connectivity on endpoint s6faec921b19e56065a4188b908a): fork/exec rootlesskit-docker-proxy: no such file or directory.
ERRO[0006] error waiting for container: context canceled

Reproducing

docker run -it -d --rm --privileged --name dind docker:dind-rootless --experimental
docker exec -it dind bash

# Inside the dind container
export DOCKER_HOST=unix:///run/user/1000/docker.sock
docker run -it -p 9000 alpine # This causes the error

The Fix

I was able to fix the issue by specifying the absolute path to rootlesskit-docker-proxy on this line