Support locking user with usermod if passwd is not available.

In some cases, the 'passwd' command might not be available, but
'usermod' might be.  In debian systems both are provided by the
'passwd' package.  In Redhat/Centos passwd comes from 'passwd' package
while 'usermod' comes from `shadow-utils`

This should just support either one with no real cost other than
the check.

2 files changed, 37 insertions, 4 deletions

diff --git a/cloudinit/distros/__init__.py b/cloudinit/distros/__init__.py
index ef618c28..20c994dc 100644
--- a/cloudinit/distros/__init__.py
+++ b/cloudinit/distros/__init__.py
@@ -577,11 +577,16 @@ class Distro(object):
         """
         Lock the password of a user, i.e., disable password logins
         """
+        # passwd must use short '-l' due to SLES11 lacking long form '--lock'
+        lock_tools = (['passwd', '-l', name], ['usermod', '--lock', name])
         try:
-            # Need to use the short option name '-l' instead of '--lock'
-            # (which would be more descriptive) since SLES 11 doesn't know
-            # about long names.
-            util.subp(['passwd', '-l', name])
+            cmd = next(l for l in lock_tools if util.which(l[0]))
+        except StopIteration:
+            raise RuntimeError((
+                "Unable to lock user account '%s'. No tools available. "
+                "  Tried: %s.") % (name, [c[0] for c in lock_tools]))
+        try:
+            util.subp(cmd)
         except Exception as e:
             util.logexc(LOG, 'Failed to disable password for user %s', name)
             raise e
diff --git a/tests/unittests/test_distros/test_create_users.py b/tests/unittests/test_distros/test_create_users.py
index c3f258d5..40624952 100644
--- a/tests/unittests/test_distros/test_create_users.py
+++ b/tests/unittests/test_distros/test_create_users.py
@@ -240,4 +240,32 @@ class TestCreateUser(CiTestCase):
             [mock.call(set(['auth1']), user),  # not disabled
              mock.call(set(['key1']), 'foouser', options=disable_prefix)])
 
+    @mock.patch("cloudinit.distros.util.which")
+    def test_lock_with_usermod_if_no_passwd(self, m_which, m_subp,
+                                            m_is_snappy):
+        """Lock uses usermod --lock if no 'passwd' cmd available."""
+        m_which.side_effect = lambda m: m in ('usermod',)
+        self.dist.lock_passwd("bob")
+        self.assertEqual(
+            [mock.call(['usermod', '--lock', 'bob'])],
+            m_subp.call_args_list)
+
+    @mock.patch("cloudinit.distros.util.which")
+    def test_lock_with_passwd_if_available(self, m_which, m_subp,
+                                           m_is_snappy):
+        """Lock with only passwd will use passwd."""
+        m_which.side_effect = lambda m: m in ('passwd',)
+        self.dist.lock_passwd("bob")
+        self.assertEqual(
+            [mock.call(['passwd', '-l', 'bob'])],
+            m_subp.call_args_list)
+
+    @mock.patch("cloudinit.distros.util.which")
+    def test_lock_raises_runtime_if_no_commands(self, m_which, m_subp,
+                                                m_is_snappy):
+        """Lock with no commands available raises RuntimeError."""
+        m_which.return_value = None
+        with self.assertRaises(RuntimeError):
+            self.dist.lock_passwd("bob")
+
 # vi: ts=4 expandtab