systemctl not working in container - 'Failed to connect to bus: No such file or directory'

[geerlingguy]

With the current image and default init command, I get the following:

# systemctl status
Failed to connect to bus: No such file or directory

And when running an Ansible playbook which manages a service:

TASK [geerlingguy.docker : Ensure Docker is started and enabled at boot.] ******
fatal: [instance]: FAILED! => {"changed": false, "cmd": "/usr/bin/systemctl", "msg": "Failed to connect to bus: No such file or directory", "rc": 1, "stderr": "Failed to connect to bus: No such file or directory\n", "stderr_lines": ["Failed to connect to bus: No such file or directory"], "stdout": "", "stdout_lines": []}

Looking into the issue, it seems dbus-daemon may not be running.

But if I do the following:

mkdir -p /run/dbus
dbus-daemon --system

It seems to start, but then I get:

# systemctl status
Failed to read server status: Launch helper exited with unknown return code 1

[geerlingguy]

So this image—which seems almost identical to my current build—currently works out of the box: https://hub.docker.com/r/unop/fedora-systemd/

[geerlingguy]

Looks like it might just be the init command...

-CMD ["/usr/lib/systemd/systemd"]
+CMD ["/usr/sbin/init"]

[geerlingguy]

Simply running the container seems to work now. But in my molecule environment it is not. Might be a volume binding issue.

[JimmyTournemaine]

Same issues using geerlingguy/docker-centos8-ansible docker image using molecule.
Using CMD: ["/usr/sbin/init"] fix it too.

- name: instance
    image: "geerlingguy/docker-centos8-ansible:latest"
    command: ${MOLECULE_DOCKER_COMMAND:-"/usr/sbin/init"}
    volumes:
      - /sys/fs/cgroup:/sys/fs/cgroup:ro
    privileged: true
    pre_build_image: true

[geerlingguy]

@JimmyTournemaine - Please consider filing an issue against that repository—if there's something it can fix: https://github.com/geerlingguy/docker-centos8-ansible

[JimmyTournemaine]

In fact, my goal here was more to leave a note that could be useful to others because I came across this issue while looking for the solution to this problem but with another image.
As the issue was closed, I didn't see the point of creating it again on another repository.