ceph-volume: adds unit tests for systemd.systemctl.get_running_osd_ids

Signed-off-by: Andrew Schoen <aschoen@redhat.com>
(cherry picked from commit 7cb098b)

src/ceph-volume/ceph_volume/tests/systemd/test_systemctl.py

@@ -0,0 +1,9 @@
+from ceph_volume.systemd import systemctl
+
+class TestSystemctl(object):
+
+    def test_get_running_osd_ids(self, stub_call):
+        stdout = ['Id=ceph-osd@1.service', '', 'Id=ceph-osd@2.service']
+        stub_call((stdout, [], 0))
+        osd_ids = systemctl.get_running_osd_ids()
+        assert osd_ids == ['1', '2']