ldirectord systemd service fails if no /var/lock/subsys dir

[impact]

ldirectord's systemd service script contains commands to touch and remove a file in the /var/lock/subsys directory; however, locks there are a SysV service serialization thing, and are unneeded with systemd. It's unclear why the ldirectord systemd service script contains the lines, but they come from upstream so we should get it fixed there and then correct debian and ubuntu.

this impacts users because if no /var/lock/subsys directory exists, the systemd service will fail to start, which can impact installing or upgrading the resource-agents package.

[test case]

remove the /var/lock/subsys directory and try to install or upgrade ldirectord:

ubuntu@lp1828258:~$ sudo rmdir /var/lock/subsys
ubuntu@lp1828258:~$ sudo apt install ldirectord
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following package was automatically installed and is no longer required:
  libfreetype6
Use 'sudo apt autoremove' to remove it.
The following NEW packages will be installed:
  ldirectord
0 upgraded, 1 newly installed, 0 to remove and 0 not upgraded.
Need to get 0 B/62.1 kB of archives.
After this operation, 233 kB of additional disk space will be used.
Selecting previously unselected package ldirectord.
(Reading database ... 30382 files and directories currently installed.)
Preparing to unpack .../ldirectord_1%3a4.2.0-1ubuntu1_all.deb ...
Unpacking ldirectord (1:4.2.0-1ubuntu1) ...
Setting up ldirectord (1:4.2.0-1ubuntu1) ...

...(120 second or so delay)...

Job for ldirectord.service failed because the control process exited with error code.
See "systemctl status ldirectord.service" and "journalctl -xe" for details.
invoke-rc.d: initscript ldirectord, action "start" failed.
● ldirectord.service - Monitor and administer real servers in a LVS cluster of load balanced virtual servers
   Loaded: loaded (/lib/systemd/system/ldirectord.service; disabled; vendor preset: enabled)
   Active: failed (Result: exit-code) since Thu 2019-05-09 11:27:53 UTC; 11ms ago
     Docs: man:ldirectord(8)
  Process: 7559 ExecStart=/usr/sbin/ldirectord start (code=exited, status=0/SUCCESS)
  Process: 7564 ExecStartPost=/usr/bin/touch /var/lock/subsys/ldirectord (code=exited, status=1/FAILURE)
  Process: 7565 ExecStopPost=/bin/rm -f /var/lock/subsys/ldirectord (code=exited, status=0/SUCCESS)
 Main PID: 7561
    Tasks: 3 (limit: 4915)
   Memory: 71.7M
   CGroup: /system.slice/ldirectord.service
           ├─2547 /usr/bin/perl -w /usr/sbin/ldirectord start
           ├─7078 /usr/bin/perl -w /usr/sbin/ldirectord start
           └─7561 /usr/bin/perl -w /usr/sbin/ldirectord start

May 09 11:26:22 lp1828258 systemd[1]: Starting Monitor and administer real servers in a LVS cluster of load balanced virtual servers...
May 09 11:26:23 lp1828258 systemd[1]: ldirectord.service: Supervising process 7561 which is not our child. We'll most likely not notice when it exits.
May 09 11:26:23 lp1828258 touch[7564]: /usr/bin/touch: cannot touch '/var/lock/subsys/ldirectord': No such file or directory

[regression potential]

if something internal to resource-agents actually uses the old SysV-style /var/lock/subsys lock, removing it could cause a regression. However, it shouldn't, because the lock was for use only by SysV service scripts. Also, as we should fix this upstream first, they should know if it is used for any other purpose, so if they accept the change it should be safe.

[other info]

this is causing autopkgtest failures, especially on arm; but the failure could happen on any arch.

also note that /var/lock/subsys (where /var/lock/ is a symlink to /run/lock) is managed by systemd's tmpfiles, as a 'legacy' directory:

ubuntu@lp1828258:~$ cat /usr/lib/tmpfiles.d/legacy.conf
...[snip]...
# These files are considered legacy and are unnecessary on legacy-free
# systems.

L /var/lock - - - - ../run/lock

# /run/lock/subsys is used for serializing SysV service execution, and
# hence without use on SysV-less systems.

d /run/lock/subsys 0755 root root -

original description:

--

In autopkgtest like
https://objectstorage.prodstack4-5.canonical.com/v1/AUTH_77e2ada1e7a84929a74ba3b87153c0ac/autopkgtest-disco-ci-train-ppa-service-3717/disco/armhf/r/resource-agents/20190508_124516_2b20c@/log.gz
https://objectstorage.prodstack4-5.canonical.com/v1/AUTH_77e2ada1e7a84929a74ba3b87153c0ac/autopkgtest-disco-ci-train-ppa-service-3717/disco/armhf/r/resource-agents/20190507_202519_be056@/log.gz
https://objectstorage.prodstack4-5.canonical.com/v1/AUTH_77e2ada1e7a84929a74ba3b87153c0ac/autopkgtest-disco-ci-train-ppa-service-3717/disco/armhf/r/resource-agents/20190508_083654_2b20c@/log.gz

This fails to install:
Setting up ldirectord (1:4.2.0-1ubuntu1) ...
Job for ldirectord.service failed because the control process exited with error code.
See "systemctl status ldirectord.service" and "journalctl -xe" for details.
invoke-rc.d: initscript ldirectord, action "start" failed.
● ldirectord.service - Monitor and administer real servers in a LVS cluster of load balanced virtual servers
   Loaded: loaded (/lib/systemd/system/ldirectord.service; disabled; vendor preset: enabled)
   Active: failed (Result: exit-code) since Wed 2019-05-08 12:20:10 UTC; 42ms ago
     Docs: man:ldirectord(8)
  Process: 779 ExecStart=/usr/sbin/ldirectord start (code=exited, status=0/SUCCESS)
  Process: 783 ExecStartPost=/usr/bin/touch /var/lock/subsys/ldirectord (code=exited, status=1/FAILURE)
  Process: 785 ExecStopPost=/bin/rm -f /var/lock/subsys/ldirectord (code=exited, status=0/SUCCESS)
 Main PID: 781
    Tasks: 1 (limit: 4915)
   Memory: 14.1M
   CGroup: /system.slice/ldirectord.service
           └─781 /usr/bin/perl -w /usr/sbin/ldirectord start

May 08 12:18:39 autopkgtest-lxd-einqza systemd[1]: Starting Monitor and administer real servers in a LVS cluster of load balanced virtual servers...
May 08 12:18:39 autopkgtest-lxd-einqza systemd[1]: ldirectord.service: Supervising process 781 which is not our child. We'll most likely not notice when it exits.
May 08 12:18:40 autopkgtest-lxd-einqza touch[783]: /usr/bin/touch: cannot touch '/var/lock/subsys/ldirectord': No such file or directory
May 08 12:18:40 autopkgtest-lxd-einqza systemd[1]: ldirectord.service: Control process exited, code=exited, status=1/FAILURE
May 08 12:20:10 autopkgtest-lxd-einqza systemd[1]: ldirectord.service: State 'stop-post' timed out. Terminating.
May 08 12:20:10 autopkgtest-lxd-einqza systemd[1]: ldirectord.service: Failed with result 'exit-code'.
May 08 12:20:10 autopkgtest-lxd-einqza systemd[1]: Failed to start Monitor and administer real servers in a LVS cluster of load balanced virtual servers.

Of particular interest might be this line:
 touch[783]: /usr/bin/touch: cannot touch '/var/lock/subsys/ldirectord': No such file or directory

This runs in LXD, maybe a pathing or apparmor issue?

I tried the same on a real armhf device and it works right away.
(Thanks waveform to provide armhf raspi)