Submission type

• Bug report

systemd version the issue has been seen with

Latest git/master (dd83526)

Used distribution

Gentoo, Kernel 4.5.0

In case of bug report: Expected behaviour you didn't see

systemd-nspawn taking the environment variable UNIFIED_CGROUP_HIERARCHY=no into account when running as service (instance of [email protected]).

In case of bug report: Unexpected behaviour you saw

In #4173 (comment) it was suggested to use UNIFIED_CGROUP_HIERARCHY=no to workaround the described issue. While this works fine when manually executing systemd-nspawn, it doesn't seem to have any effect when running it as service.

In case of bug report: Steps to reproduce the problem

• Create /etc/systemd/system/[email protected]/issue-4008.conf:

  [Service]
  Environment=UNIFIED_CGROUP_HIERARCHY=no
  

• Reload configuration changes: systemctl daemon-reload

• Start service: systemctl start systemd-nspawn@dev-web-00000000

• Inspect the status:

  ● [email protected] - Container dev-web-00000000
    Loaded: loaded (/usr/lib/systemd/system/[email protected]; disabled; vendor preset: disabled)
  Drop-In: /etc/systemd/system/[email protected]
          └─issue-4008.conf
  Active: active (running) since Mon 2016-09-19 09:49:51 CEST; 1h 40min ago
    Docs: man:systemd-nspawn(1)
  Main PID: 22294 (systemd-nspawn)
    Status: "Container running."
     Tasks: 2 (limit: 16384)
    Memory: 808.0K
       CPU: 27ms
    CGroup: /machine.slice/[email protected]
            ├─22294 /usr/bin/systemd-nspawn --quiet --keep-unit --boot --link-journal=try-guest --network-veth -U --settings=override --machine=dev-web-00000000
            └─22304 /lib/systemd/systemd
  
  Sep 19 09:49:51 moria systemd-nspawn[22294]: Detected virtualization systemd-nspawn.
  Sep 19 09:49:51 moria systemd-nspawn[22294]: Detected architecture x86-64.
  Sep 19 09:49:51 moria systemd-nspawn[22294]: [1B blob data]
  Sep 19 09:49:51 moria systemd-nspawn[22294]: Welcome to Ubuntu 16.04 LTS!
  Sep 19 09:49:51 moria systemd-nspawn[22294]: [1B blob data]
  Sep 19 09:49:51 moria systemd-nspawn[22294]: Failed to read AF_UNIX datagram queue length, ignoring: No such file or directory
  Sep 19 09:49:51 moria systemd-nspawn[22294]: Failed to create /machine.slice/[email protected]/init.scope control group: Permission denied
  Sep 19 09:49:51 moria systemd-nspawn[22294]: Failed to allocate manager object: Permission denied
  Sep 19 09:49:51 moria systemd-nspawn[22294]: [!!!!!!] Failed to allocate manager object, freezing.
  Sep 19 09:49:51 moria systemd-nspawn[22294]: Freezing execution.
  

Further Notes

• systemctl show systemd-nspawn@dev-web-00000000 | grep Environment correctly shows the variable being set: Environment=UNIFIED_CGROUP_HIERARCHY=no
• Same goes for strings /proc/22294/environ | grep UNIFIED_CGROUP_HIERARCHY: UNIFIED_CGROUP_HIERARCHY=no

So it seems systemd-nspawn behaves differently when it comes to handling the environment variable UNIFIED_CGROUP_HIERARCHY when started as service vs. being started manually on the command line.