(edge) "docker run" hangs when using docker in docker
My project on GitLab.com uses Docker in Docker workflow for testing.
When running Docker daemon 19.03 within alpine:edge-based container in a GitLab shared runner, docker client always hangs.
The most basic command hangs: docker run busybox:latest echo hello
.
I've created a demo project which reproduces this bug.
Here is the job which hangs: https://gitlab.com/abogdanenko/dockerhangs/-/jobs/325717502.
$ docker run busybox:latest echo hello
...
ERROR: Job failed: execution took longer than 10m0s seconds
Extra info:
- alpine:latest provides Docker 18.09 which does not have this problem.
- Ubuntu 19.10 comes with Docker 19.03 and does not have this problem either.
- The demo project produces a docker image
registry.gitlab.com/abogdanenko/dockerhangs/edge:latest
. I pulled the image to my computer, created a container and ran docker client inside the container. The client didn't hang. So I guess the issue is somehow specific to GitLab.com.