[networking_mapper] Switch to best effort strategy

With the introduction of IPv6 the mapper now needs to perform
partial maps with hosts in the inventory that are not yet
reachable, so it needs to be able to perform the mapping without
a full set of ansible facts.

The strategy that the PR follows is the next one:
- Despite the type of mapping, full or partial, do a best effort
approach without failing if a fact is missing.
- In partial maps, allow the mapper to take the interfaces-info
- Avoid refreshing networking facts for those hosts that has
not ansible_host fact present, assuming those are not reachable.

plugins/module_utils/net_map/networking_mapper.py

@@ -324,20 +324,23 @@ def __map_instance_network_interface_mac(
     def __map_instance_network_interface_data(
         self,
     ) -> typing.Optional[typing.Dict[str, typing.Any]]:
-        if self.__interface_info is None or self.__host_vars is None:
-            return {}
-        elif "mac" not in self.__interface_info:
+        interfaces_info_mac = (self.__interface_info or {}).get("mac", None)
+        if self.__interface_info is not None and not interfaces_info_mac:
             raise exceptions.NetworkMappingError(
                 f"interface information for {self.__instance_name} instance "
                 "does not contain mac address"
             )
+        interface_data = self.__map_instance_network_interface_ansible_data(
+            interfaces_info_mac
+        )
+        if interfaces_info_mac and "macaddress" not in interface_data:
+            interface_data["macaddress"] = interfaces_info_mac.lower()
+        return interface_data
+
+    def __map_instance_network_interface_ansible_data(
+        self, interfaces_info_mac: typing.Optional[str]
+    ) -> typing.Dict[str, typing.Any]:
         ansible_interfaces = self.__host_vars.get("ansible_interfaces", None)
-        if not ansible_interfaces:
-            raise exceptions.NetworkMappingError(
-                f"Cannot determine network interface for {self.__instance_name}. "
-                "Ensure ansible_interfaces is an available fact for the host"
-            )
-        instance_mac = self.__interface_info["mac"].lower()
         for iface_name in ansible_interfaces:
             # Ansible internally replaces `-` and `:` by _ to create safe facts names
             iface_fact_name = f"ansible_{iface_name}".replace("-", "_").replace(
@@ -350,11 +353,9 @@ def __map_instance_network_interface_data(
                     f"ansible_interfaces is present but {iface_fact_name} it's not."
                 )
             mac = ansible_iface_data.get("macaddress", None)
-            if mac and mac.lower() == instance_mac:
+            if mac and mac.lower() == interfaces_info_mac.lower():
                 return ansible_iface_data
-        raise exceptions.NetworkMappingError(
-            f"Ansible instance with the given MAC, {instance_mac} was not found"
-        )
+        return {}
 
     def __map_instance_network_ips(
         self,
@@ -489,15 +490,7 @@ def map(
                 during the mapping process.
         """
         instance_nets = self.__map_instance_networks()
-        hostname = (
-            self.__host_vars.get("ansible_hostname", None) if self.__host_vars else None
-        )
-        if self.__host_vars is not None and not hostname:
-            raise exceptions.NetworkMappingError(
-                f"Cannot determine hostname for {self.__instance_name}. "
-                "Ensure ansible_hostname is an available fact for the host"
-            )
-
+        hostname = self.__host_vars.get("ansible_hostname", None)
         return networking_env_definitions.MappedInstance(
             self.__instance_name,
             instance_nets,
@@ -710,7 +703,9 @@ def map_routers(self, network_definition_raw: typing.Dict[str, typing.Any]):
         return self.__safe_encode_to_primitives(routers)
 
     def map_partial(
-        self, network_definition_raw: typing.Dict[str, typing.Any]
+        self,
+        network_definition_raw: typing.Dict[str, typing.Any],
+        interfaces_info: typing.Dict[str, typing.Any],
     ) -> typing.Dict[str, typing.Any]:
         """
         Parses, validates and maps a Networking Definition into a partially complete
@@ -721,6 +716,8 @@ def map_partial(
 
         Args:
             network_definition_raw: The Networking Definition to map.
+            interfaces_info: Dict containing the MAC addresses of each instance.
+             Optional.
 
         Returns: The Networking Environment Definition as a dictionary.
         Raises:
@@ -730,7 +727,9 @@ def map_partial(
                 during the mapping process.
         """
         net_definition = self.__parse_validate_net_definition(network_definition_raw)
-        return self.__safe_encode_to_primitives(self.__map(net_definition))
+        return self.__safe_encode_to_primitives(
+            self.__map(net_definition, interfaces_info=interfaces_info)
+        )
 
     def map_complete(
         self,
@@ -853,7 +852,7 @@ def __build_instances_net_mappers(
                 NetworkingInstanceMapper(
                     instance_name,
                     pools_manager,
-                    self.__host_vars.get(instance_name, None),
+                    self.__host_vars.get(instance_name, {}),
                     instance_definition=instance_definition,
                     group_templates=groups_template_definitions,
                     interface_info=instance_interface_info,

roles/networking_mapper/tasks/main.yml

@@ -93,6 +93,12 @@
       }}
   block:
     - name: Gather the facts
+      vars:
+        _instance_vars: >-
+          {{
+            hostvars[item] | default({})
+          }}
+      when: "'ansible_host' in _instance_vars"
       ansible.builtin.setup:
         gather_subset:
           - network