systemd autopkgtest 'boot-and-services' fails with linux-kvm

[Dan Streetman]

[impact]

systemd autopkgtest 'boot-and-services' fails when running with linux-kvm kernel, because that kernel does not set CONFIG_DM_MULTIPATH, so the test detects failed services.

[test case]

check the autopkgtest results, e.g.:
https://objectstorage.prodstack4-5.canonical.com/v1/AUTH_77e2ada1e7a84929a74ba3b87153c0ac/autopkgtest-eoan/eoan/amd64/s/systemd/20200210_144351_da247@/log.gz

test_no_failed (__main__.ServicesTest)
No failed units ... -------- journal for failed service multipathd.service -----------
-- Logs begin at Mon 2020-02-10 03:26:38 UTC, end at Mon 2020-02-10 13:56:23 UTC. --
Feb 10 13:56:07 autopkgtest systemd[1]: Starting Device-Mapper Multipath Device Controller...
Feb 10 13:56:07 autopkgtest modprobe[194]: modprobe: WARNING: Module scsi_dh_alua not found in directory /lib/modules/5.3.0-1010-kvm
Feb 10 13:56:07 autopkgtest modprobe[194]: modprobe: WARNING: Module scsi_dh_emc not found in directory /lib/modules/5.3.0-1010-kvm
Feb 10 13:56:07 autopkgtest modprobe[194]: modprobe: WARNING: Module scsi_dh_rdac not found in directory /lib/modules/5.3.0-1010-kvm
Feb 10 13:56:07 autopkgtest modprobe[194]: modprobe: WARNING: Module dm-multipath not found in directory /lib/modules/5.3.0-1010-kvm
Feb 10 13:56:07 autopkgtest multipathd[195]: --------start up--------
Feb 10 13:56:07 autopkgtest multipathd[195]: read /etc/multipath.conf
Feb 10 13:56:07 autopkgtest multipathd[195]: DM multipath kernel driver not loaded
Feb 10 13:56:07 autopkgtest systemd[1]: multipathd.service: Main process exited, code=exited, status=1/FAILURE
Feb 10 13:56:07 autopkgtest systemd[1]: multipathd.service: Failed with result 'exit-code'.
Feb 10 13:56:07 autopkgtest systemd[1]: Failed to start Device-Mapper Multipath Device Controller.
FAIL

======================================================================
FAIL: test_no_failed (__main__.ServicesTest)
No failed units
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/tmp/autopkgtest.WQ5GyY/build.RUe/src/debian/tests/boot-and-services", line 68, in test_no_failed
    self.assertEqual(failed, [])
AssertionError: Lists differ: ['multipathd.service loaded failed failed [38 chars]ler'] != []

First list contains 1 additional elements.
First extra element 0:
'multipathd.service loaded failed failed Device-Mapper Multipath Device Controller'

+ []
- ['multipathd.service loaded failed failed Device-Mapper Multipath Device '
- 'Controller']

[regression potential]

This updates the test case to ignore failure of multipathd.service if it looks like the dm-multipath module isn't available, so any regression would be limited to incorrectly passing or failing test case.

[scope]

This is needed at least in Eoan, and probably Focal.

This doesn't fail on Bionic or Xenial, but that seems to be because the multipath-utils package (which provides multipathd.service) is not installed during the test for those releases.

[Dan Streetman (ddstreet)]

marking as affecting linux-kvm, as I'm not sure the lack of CONFIG_DM_MULTIPATH was intentional or not.

[Dan Streetman (ddstreet)]

marking Eoan as wontfix; it's EOL in weeks and this is a minor bug

[Dan Streetman (ddstreet)]

after checking the focal linux-kvm kernel, it does have dm-multipath enabled as a module, so there should be no change needed in the systemd test.