Molecule: systemd in docker doesn't work with read-only mount

[X4mp]

using the recommended "geerlingguy/docker-${MOLECULE_DISTRO:-rockylinux8}-ansible:latest" image doesn't work with docker as it immediately fails with the following error:

Failed to create /init.scope control group: Read-only file system
Failed to allocate manager object: Read-only file system
[!!!!!!] Failed to allocate manager object.
Exiting PID 1...

I am running it on ubuntu 22.04 with molecule 4.0.4 and ansible 2.14.1

molecule 4.0.4 using python 3.10 
    ansible:2.14.1
    delegated:4.0.4 from molecule
    docker:2.1.0 from molecule_docker requiring collections: community.docker>=3.0.2 ansible.posix>=1.4.0
    podman:2.0.3 from molecule_podman requiring collections: containers.podman>=1.7.0 ansible.posix>=1.3.0
    vagrant:2.0.0 from molecule_vagrant

It can be verified with: docker run -t --privileged --volume=/sys/fs/cgroup:/sys/fs/cgroup:ro "geerlingguy/docker-ubuntu2204-ansible:latest"

[geerlingguy]

This is due to some recent changes affecting new versions of Ubuntu (and I'm guessing Debian 11 too)? Setting molecule's options to create a rw volume, and adding the cgroupns_mode to host fixes it.

This is a bug in the book currently, as it's mentioned a couple times the old way:

ansible-for-devops/molecule/molecule/default/molecule.yml

Line 15 in 814d4e9

- /sys/fs/cgroup:/sys/fs/cgroup:ro

ansible-for-devops/tests/orchestration.sh

Line 12 in 814d4e9

docker run -d --name app -p 80:80 --privileged -v /sys/fs/cgroup:/sys/fs/cgroup:ro geerlingguy/docker-rockylinux8-ansible

[X4mp]

Thank you very much for the fast response. I finally got to test the recommended options and it seems to work.
The container now starts and stays alive, but I am running into a new problem with become: true combined with delegate_to. It didn't cause any problem with podman, but with docker it suddenly requires a password. But I guess that's another issue and not relevant here.

Anyway, I guess thanks for the help and I hope the bug will be fixed with the next iteration of the book.