[sudo] Use correct string as version in facts

(cherry picked from commit 59f57a9)
(cherry picked from commit f7d4e03)

CHANGELOG.rst

@@ -115,6 +115,13 @@ Fixed
 
 - Fixed wrong variable name in file:`sshd_config.j2` template.
 
+:ref:`debops.sudo` role
+'''''''''''''''''''''''
+
+- Fixed an issue in the fact script which resulted in a wrong string being
+  picked up as the version number when :command:`sudo` was configured to use
+  LDAP, but the LDAP service was not available.
+
 :ref:`debops.system_users` role
 '''''''''''''''''''''''''''''''
 

ansible/roles/sudo/templates/etc/ansible/facts.d/sudo.fact.j2

@@ -14,6 +14,12 @@ import subprocess
 import locale
 
 
+try:
+    from subprocess import DEVNULL
+except ImportError:
+    DEVNULL = open(os.devnull, 'wb')
+
+
 def cmd_exists(cmd):
     return any(
         os.access(os.path.join(path, cmd), os.X_OK)
@@ -30,7 +36,7 @@ output = {'configured': True,
 if output['installed']:
     output['version'] = subprocess.check_output(
         ['sudo', '--version'], env=os.environ,
-        stderr=subprocess.STDOUT
+        stderr=DEVNULL
     ).decode('utf-8').split('\n')[0].split(' ')[-1]
 
 print(dumps(output, sort_keys=True, indent=4))