Removing cgroup mount

[Lileso]

With newer versions of containerd mounting cgroup seems to cause the error: Failed to connect to bus: No such file or directory After removing this mount I was able to use systemd inside of my container

Tested on:

system	containerd version	docker version
Kubuntu 22.04	containerd.io: 1.6.7-1	docker-ce: 5:20.10.17 (with root)

command run:

docker run --privileged docker-rockylinux8-ansible:latest 

molecule yml

platforms:
  - name: test-one
    image: docker-rockylinux8-ansible
    command: ${MOLECULE_DOCKER_COMMAND: - ""}
    privileged: true
    pre_build_image: true

[geerlingguy]

Interesting, I normally run this on Ubuntu 20.04 or on macOS with Docker Desktop and haven't had the issue, so I'm wondering if this change would break anything in those older environments.

[Lileso]

That's a good point!

Unfortunately I don't have anything less than 22.04 currently setup for testing. I'll try and get something setup on Sunday and will let you know

[Lileso]

Hi @geerlingguy

System	containerd version	docker version
Ubuntu 20.04	1.6.7	5:20.10.17

I created a Ubuntu 20.04 VM and did a bit of testing, First I attempted to run my fork of the docker image (sudo docker run -d --name geerling-test docker-rockylinux8-ansible: This produced the error "Failed to connect to bus: Host is down" like I had previously seen with Kubuntu 22.04 which removing the mount had fixed.

For my next test I ran the same forked docker image but this time it was with the volume mounted in the command line (sudo docker run -d --name geerling-test --volume=/sys/fs/cgroup:/sys/fs/cgroup:ro docker-rockylinux8-ansible): This again produced the same error "Failed to connect to bus: Host is down"

And last test was the the latest image that you've made (sudo docker run -d --name geerling-test --volume=/sys/fs/cgroup:/sys/fs/cgroup:ro geerlingguy/docker-rockylinux8-ansible:latest): Which also produced this error again.

Obviously I've got something wrong with my VM but I'm struggling to see more. If you get a chance could you please find out what your current docker and containerd versions are so that I can test against those?

[kevincoakley]

@Lileso

If you are using molecule, try the following: Make sure you have molecule-docker v2.1.0 installed and set cgroupns_mode: host and the volume to /sys/fs/cgroup:/sys/fs/cgroup:rw:

platforms:
  - name: instance
    image: "geerlingguy/docker-${MOLECULE_DISTRO:-rockylinux8}-ansible:latest"
    command: ${MOLECULE_DOCKER_COMMAND:-""}
    volumes:
      - /sys/fs/cgroup:/sys/fs/cgroup:rw
    cgroupns_mode: host
    privileged: true
    pre_build_image: true

I had the same error with Docker Desktop 4.12.0 until I made these changes.