vyos_config smart diffing ... special value

Author: lucaelin

changelogs/fragments/vyos_config_improved_diffing.yml

@@ -0,0 +1,3 @@
+---
+minor_changes:
+  - vyos_config - Added new `match`-value `smart` with updated configuration diffing for more reproducible provisioning of devices.

plugins/cliconf_utils/vyosconf.py

@@ -20,6 +20,8 @@
 
 import re
 
+KEEP_EXISTING_VALUES = "..."
+
 
 class VyosConf:
     def __init__(self, commands=None):
@@ -188,15 +190,15 @@ def diff_to(self, other, structure):
                 (subset, subdel) = self.diff_to(other[key], structure[key])
                 for s in subset:
                     toset.append(quoted_key + " " + s)
-                if "!" not in other[key]:
+                if KEEP_EXISTING_VALUES not in other[key]:
                     for d in subdel:
                         todel.append(quoted_key + " " + d)
             else:
                 # keys only in this, pls del
                 todel.append(quoted_key)
                 continue  # del
         for (key, value) in other.items():
-            if key == "!":
+            if key == KEEP_EXISTING_VALUES:
                 continue
             quoted_key = "'" + key + "'" if " " in key or '"' in key else key
             if key not in structure:

plugins/modules/vyos_config.py

@@ -61,10 +61,12 @@
       active configuration. By default, the configuration commands config are
       matched against the active config and the deltas are loaded line by line.
       If the C(match) argument is set to C(none) the active configuration is ignored
-      and the configuration is always loaded. If the C(match) argument is set to C(smart)
-      both the active configuration and the target configuration are simlulated
+      and the configuration is always loaded. If the C(match) argument is set to
+      C(smart) both the active configuration and the target configuration are simlulated
       and the results compared to bring the target device into a reliable and
-      reproducable state.
+      reproducable state. Using C(smart), the special value C(...) indicates that
+      this keys value should not be changed and any preexisting siblings should not
+      be removed from the target.
     type: str
     default: line
     choices:

tests/unit/cliconf/test_utils_vyosconf.py

@@ -135,14 +135,14 @@ def test_diff_commands_to(self):
             conf.diff_commands_to(
                 VyosConf(
                     [
-                        "set a b !",
+                        "set a b ...",
                     ]
                 )
             ),
             ["delete a c"],
         )
         self.assertListEqual(
-            conf.diff_commands_to(VyosConf(["set a !", "set a d e"])),
+            conf.diff_commands_to(VyosConf(["set a ...", "set a d e"])),
             ["set a d e"],
         )
         self.assertListEqual(