lldp: Handling attributes that are defined multiple times (#9657)

* lldp: Ignoring values for keys already defined

This fixes crashes when the lldpctl output has lines for unknown tlvs that
redefine a key in the middle of the nested dict data structure.

* lldp: handling attributes that are defined multiple times

- Fix crash caused by certain lldpctl output where an attribute is defined as branch and leaf
- Adds multivalues parameter to control behavior when lldpctl outputs an attribute multiple times

* lldp: using isinstance instead of type

* Link to Github PR

Apply suggestions from code review

Co-authored-by: Felix Fontein <felix@fontein.de>

* lldp: only push value to subkey in multivalues mode

To provide backwards compatibility values that are defined as a
attribute and also as a path element are only pushed to the 'value'
subkey when using the new multivalues mode.

---------

Co-authored-by: Felix Fontein <felix@fontein.de>

changelogs/fragments/9657-lldp-handling-attributes-defined-multiple-times.yml

@@ -0,0 +1,4 @@
+bugfixes:
+  - lldp - fix crash caused by certain lldpctl output where an attribute is defined as branch and leaf (https://github.com/ansible-collections/community.general/pull/9657).
+minor_changes:
+  - lldp - adds ``multivalues`` parameter to control behavior when lldpctl outputs an attribute multiple times (https://github.com/ansible-collections/community.general/pull/9657).

plugins/modules/lldp.py

@@ -22,7 +22,12 @@
     support: none
   diff_mode:
     support: none
-options: {}
+options:
+  multivalues:
+    description: If lldpctl outputs an attribute multiple time represent all values as a list.
+    required: false
+    type: bool
+    default: false
 author: "Andy Hill (@andyhky)"
 notes:
   - Requires C(lldpd) running and LLDP enabled on switches.
@@ -53,26 +58,49 @@ def gather_lldp(module):
     if output:
         output_dict = {}
         current_dict = {}
-        lldp_entries = output.split("\n")
+        lldp_entries = output.strip().split("\n")
 
+        final = ""
         for entry in lldp_entries:
             if entry.startswith('lldp'):
                 path, value = entry.strip().split("=", 1)
                 path = path.split(".")
                 path_components, final = path[:-1], path[-1]
+            elif final in current_dict and isinstance(current_dict[final], str):
+                current_dict[final] += '\n' + entry
+                continue
+            elif final in current_dict and isinstance(current_dict[final], list):
+                current_dict[final][-1] += '\n' + entry
+                continue
             else:
-                value = current_dict[final] + '\n' + entry
+                continue
 
             current_dict = output_dict
             for path_component in path_components:
                 current_dict[path_component] = current_dict.get(path_component, {})
+                if not isinstance(current_dict[path_component], dict):
+                    current_dict[path_component] = {'value': current_dict[path_component]}
                 current_dict = current_dict[path_component]
-            current_dict[final] = value
+
+            if final in current_dict and isinstance(current_dict[final], dict) and module.params['multivalues']:
+                current_dict = current_dict[final]
+                final = 'value'
+
+            if final not in current_dict or not module.params['multivalues']:
+                current_dict[final] = value
+            elif isinstance(current_dict[final], str):
+                current_dict[final] = [current_dict[final], value]
+            elif isinstance(current_dict[final], list):
+                current_dict[final].append(value)
+
         return output_dict
 
 
 def main():
-    module = AnsibleModule({})
+    module_args = dict(
+        multivalues=dict(type='bool', required=False, default=False)
+    )
+    module = AnsibleModule(module_args)
 
     lldp_output = gather_lldp(module)
     try: