How to run systemctl command inside docker container?

I would like to run a docker container which will have the ability to run systemctl commands on its host.

Following this question I didn't find a solution that would work for me.

I have no hard limits on the docker base image, so using ubuntu-16.04 docker image for an ubuntu-16.04 host and ubuntu-18.04 docker image for an ubuntu-18.04 host is totally acceptable.

3 Answers

After some investigation I was able to run a docker container with the ability to run systemctl command.

1. The following worked when running on an ubuntu:16.04 host:

   • sudo docker run --privileged -v /run/systemd/system:/run/systemd/system -v /bin/systemctl:/bin/systemctl -v /var/run/dbus/system_bus_socket:/var/run/dbus/system_bus_socket -it ubuntu:16.04 systemctl

   • sudo docker run --privileged -v /run/systemd/system:/run/systemd/system -v /var/run/dbus/system_bus_socket:/var/run/dbus/system_bus_socket -it ubuntu:16.04 systemctl

2. And on ubuntu:18.04 host:

   sudo docker run --privileged -v /run/systemd/system:/run/systemd/system -v /var/run/dbus/system_bus_socket:/var/run/dbus/system_bus_socket -it ubuntu:18.04 systemctl

   Since systemctl doesn't come with this image

Thanks ofirule

Tried your solution on debian:10, your solution effectively allows to run the systemctl but it won't allow it to see/control the host's systemd processes. For this to work the /sys/fs/cgroup directory must also be mounted as a volume:

docker run -it --rm -v /bin/systemctl:/bin/systemctl -v /run/systemd/system:/run/systemd/system -v /var/run/dbus/system_bus_socket:/var/run/dbus/system_bus_socket -v /sys/fs/cgroup:/sys/fs/cgroup debian:10 systemctl --no-pager status

With this i can control the host's systemd services and even do a shutdown/reboot through systemd.

This seems specific to Debian 10 and not needed for Ubuntu 18.04. Other Debian/Ubuntu versions might or might not need it.

Not allowed to comment. But this worked for my Ubuntu 18.04 setup:

sudo docker run --privileged \
-v /run/systemd/system:/run/systemd/system \
-v /lib/:/lib/ \
-v /usr/lib/x86_64-linux-gnu/:/usr/lib/x86_64-linux-gnu/ \
-v /bin/systemctl:/bin/systemctl \
-v /var/run/docker.sock:/var/run/docker.sock \
-v /var/run/dbus/system_bus_socket:/var/run/dbus/system_bus_socket \
-it ubuntu:18.04 /bin/sh -c "systemctl restart openvpn.service; systemctl status openvpn.service"

If the command complains about error while loading shared libraries: libip4tc.so.0: -> run locate libip4tc.so.0 to find out where this file is and mount the folder as a volume.