A Docker image based on ubuntu that runs systemd with a minimal set of
services.
Intended for use testing Ansible roles with Molecule
Development use only. Do not use in production!
18.04
Ansible roles often provide services. Testing these properly requires a service manager.
You need to add a couple of flags to the docker run command to make systemd
play nice with Docker.
We must disable seccomp because systemd uses system calls that are not
allowed by Docker's default seccomp profile:
--security-opt seccomp=unconfined
Ubuntu's systemd expects /run and /run/lock to be tmpfs file systems,
but it can't mount them itself in an unprivileged container:
--tmpfs /run
--tmpfs /run/lock
--tmpfs /tmp
systemd needs read-only access to the kernel's cgroup hierarchies:
-v /sys/fs/cgroup:/sys/fs/cgroup:ro
Allocating a pseudo-TTY is not strictly necessary, but it gives us pretty
color-coded logs that we can look at with docker logs:
-t
This image is useless as it's only meant to serve as a base for your own images, but you can still create a container from it. First set up your Docker host as described in Setup above. Then run the following command:
docker run -d --name systemd --security-opt seccomp=unconfined --tmpfs /tmp --tmpfs /run --tmpfs /run/lock -v /sys/fs/cgroup:/sys/fs/cgroup:ro -t bdellegrazie/ubuntu-systemd
Check the logs to see if systemd started correctly:
docker logs systemd
If everything worked, the output should look like this:
systemd 229 running in system mode. (+PAM +AUDIT +SELINUX +IMA +APPARMOR +SMACK +SYSVINIT +UTMP +LIBCRYPTSETUP +GCRYPT +GNUTLS +ACL +XZ -LZ4 +SECCOMP +BLKID +ELFUTILS +KMOD -IDN)
Detected virtualization docker.
Detected architecture x86-64.
Welcome to Ubuntu 16.04.2 LTS!
Set hostname to <aad1d41c3a2e>.
Initializing machine ID from random generator.
[ OK ] Created slice System Slice.
[ OK ] Reached target Slices.
[ OK ] Listening on Journal Socket.
[ OK ] Listening on Journal Socket (/dev/log).
[ OK ] Reached target Local File Systems.
Starting Journal Service...
Starting Create Volatile Files and Directories...
[ OK ] Reached target Swap.
[ OK ] Reached target Sockets.
[ OK ] Reached target Paths.
[ OK ] Started Create Volatile Files and Directories.
[ OK ] Started Journal Service.
Also check the journal logs:
docker exec systemd journalctl
The output should look like this:
-- Logs begin at Thu 2017-03-16 14:12:14 UTC, end at Thu 2017-03-16 14:12:26 UTC. --
Mar 16 14:12:14 aad1d41c3a2e systemd-journald[19]: Runtime journal (/run/log/journal/) is 8.0M, max 99.9M, 91.9M free.
Mar 16 14:12:14 aad1d41c3a2e systemd-journald[19]: Journal started
Mar 16 14:12:14 aad1d41c3a2e systemd[1]: Reached target System Initialization.
Mar 16 14:12:15 aad1d41c3a2e systemd[1]: Reached target Basic System.
Mar 16 14:12:17 aad1d41c3a2e systemd[1]: Starting LSB: Set the CPU Frequency Scaling governor to "ondemand"...
Mar 16 14:12:18 aad1d41c3a2e systemd[1]: Starting Permit User Sessions...
Mar 16 14:12:19 aad1d41c3a2e systemd[1]: Starting /etc/rc.local Compatibility...
Mar 16 14:12:20 aad1d41c3a2e systemd[1]: Started Daily Cleanup of Temporary Directories.
Mar 16 14:12:21 aad1d41c3a2e systemd[1]: Reached target Timers.
Mar 16 14:12:22 aad1d41c3a2e systemd[1]: Started Permit User Sessions.
Mar 16 14:12:23 aad1d41c3a2e systemd[1]: Started /etc/rc.local Compatibility.
Mar 16 14:12:24 aad1d41c3a2e systemd[1]: Started LSB: Set the CPU Frequency Scaling governor to "ondemand".
Mar 16 14:12:25 aad1d41c3a2e systemd[1]: Reached target Multi-User System.
Mar 16 14:12:26 aad1d41c3a2e systemd[1]: Startup finished in 11.215s.
To check for clean shutdown, in one terminal run:
docker exec systemd journalctl -f
And in another shut down systemd:
docker stop systemd
The journalctl logs should look like this on a clean shutdown:
Mar 16 14:15:49 aad1d41c3a2e systemd[1]: Received SIGRTMIN+3.
Mar 16 14:15:49 aad1d41c3a2e systemd[1]: Stopped target Multi-User System.
Mar 16 14:15:50 aad1d41c3a2e systemd[1]: Stopping Permit User Sessions...
Mar 16 14:15:51 aad1d41c3a2e systemd[1]: Stopping LSB: Set the CPU Frequency Scaling governor to "ondemand"...
Mar 16 14:15:52 aad1d41c3a2e systemd[1]: Stopped /etc/rc.local Compatibility.
Mar 16 14:15:53 aad1d41c3a2e systemd[1]: Stopped target Timers.
Mar 16 14:15:54 aad1d41c3a2e systemd[1]: Stopped Daily Cleanup of Temporary Directories.
Mar 16 14:15:55 aad1d41c3a2e systemd[1]: Stopped Permit User Sessions.
Mar 16 14:15:56 aad1d41c3a2e systemd[1]: Stopped LSB: Set the CPU Frequency Scaling governor to "ondemand".
Mar 16 14:15:57 aad1d41c3a2e systemd[1]: Stopped target Basic System.
Mar 16 14:15:58 aad1d41c3a2e systemd[1]: Stopped target Slices.
Copyright © 2019 bdellegrazie. Licensed under the MIT license. Copyright © 2016-2018 Solita. Licensed under the MIT license.