dynamic-dns: T2528: bugfix FileNotFoundError in "update dns dynamic"

Stopping and starting ddclient should only happen if the DNS dynamic service
is actually configured. In addition it should always be checked if the file
we try to delete really exists.

(cherry picked from commit 0525e443fa68cda451c9f4c838e1f55cec913d2a)

1 files changed, 9 insertions, 13 deletions

diff --git a/src/op_mode/dynamic_dns.py b/src/op_mode/dynamic_dns.py
index 0d457e247..14bcf65c1 100755
--- a/src/op_mode/dynamic_dns.py
+++ b/src/op_mode/dynamic_dns.py
@@ -35,12 +35,6 @@ update-status: {{ entry.status }}
 """
 
 def show_status():
-    # Do nothing if service is not configured
-    c = Config()
-    if not c.exists_effective('service dns dynamic'):
-        print("Dynamic DNS not configured")
-        sys.exit(0)
-
     data = {
         'hosts': []
     }
@@ -85,22 +79,24 @@ def show_status():
 
 def update_ddns():
     os.system('systemctl stop ddclient')
-    os.remove(cache_file)
+    if os.path.exists(cache_file):
+        os.remove(cache_file)
     os.system('systemctl start ddclient')
 
-
-def main():
+if __name__ == '__main__':
     parser = argparse.ArgumentParser()
     group = parser.add_mutually_exclusive_group()
     group.add_argument("--status", help="Show DDNS status", action="store_true")
     group.add_argument("--update", help="Update DDNS on a given interface", action="store_true")
     args = parser.parse_args()
 
+    # Do nothing if service is not configured
+    c = Config()
+    if not c.exists_effective('service dns dynamic'):
+        print("Dynamic DNS not configured")
+        sys.exit(1)
+
     if args.status:
         show_status()
     elif args.update:
         update_ddns()
-
-
-if __name__ == '__main__':
-    main()