rsyslog: skip empty or None in remotes format

This allows user to specify the following to overwrite a previously
declared entry without warnings.
 rsyslog: {'remotes': {'foo': None}}

2 files changed, 11 insertions, 0 deletions

diff --git a/cloudinit/config/cc_rsyslog.py b/cloudinit/config/cc_rsyslog.py
index 5ecf1629..a0132d28 100644
--- a/cloudinit/config/cc_rsyslog.py
+++ b/cloudinit/config/cc_rsyslog.py
@@ -307,6 +307,8 @@ def remotes_to_rsyslog_cfg(remotes, header=None, footer=None):
     if header is not None:
         lines.append(header)
     for name, line in remotes.items():
+        if not line:
+            continue
         try:
             lines.append(str(parse_remotes_line(line, name=name)))
         except ValueError as e:
diff --git a/tests/unittests/test_handler/test_handler_rsyslog.py b/tests/unittests/test_handler/test_handler_rsyslog.py
index 7bfa65a9..b932165c 100644
--- a/tests/unittests/test_handler/test_handler_rsyslog.py
+++ b/tests/unittests/test_handler/test_handler_rsyslog.py
@@ -163,3 +163,12 @@ class TestRemotesToSyslog(t_help.TestCase):
         lines = r.splitlines()
         self.assertTrue(header, lines[0])
         self.assertTrue(footer, lines[-1])
+
+    def test_with_empty_or_null(self):
+        mycfg = "*.* myhost"
+        myline = str(parse_remotes_line(mycfg, name="myname"))
+        r = remotes_to_rsyslog_cfg(
+            {'myname': mycfg, 'removed': None, 'removed2': ""})
+        lines = r.splitlines()
+        self.assertEqual(1, len(lines))
+        self.assertTrue(myline in r.splitlines())