Fix AWS EC2 inventory plugin caching of groups (#46961)

* Fix AWS EC2 inventory plugin caching of groups

* Added changelog fragment for aws_ec2 caching fix

* Store the AWS query results

The underlying inventory object contains inventory from other sources,
so caching it as ours would be wrong.
It seems easiest and safest to just cache the boto query results
instead.

* Remove unused functions

changelogs/fragments/46961_fix_aws_ec2_cache.yaml

@@ -0,0 +1,2 @@
+bugfixes:
+  - aws_ec2 - fixed issue where cache did not contain the computed groups

lib/ansible/plugins/inventory/aws_ec2.py

@@ -422,31 +422,6 @@ class InventoryModule(BaseInventoryPlugin, Constructable, Cacheable):
             self._add_hosts(hosts=groups[group], group=group, hostnames=hostnames)
             self.inventory.add_child('all', group)
 
-    def _populate_from_source(self, source_data):
-        hostvars = source_data.pop('_meta', {}).get('hostvars', {})
-        for group in source_data:
-            if group == 'all':
-                continue
-            else:
-                self.inventory.add_group(group)
-                hosts = source_data[group].get('hosts', [])
-                for host in hosts:
-                    self._populate_host_vars([host], hostvars.get(host, {}), group)
-                self.inventory.add_child('all', group)
-
-    def _format_inventory(self, groups, hostnames):
-        results = {'_meta': {'hostvars': {}}}
-        for group in groups:
-            results[group] = {'hosts': []}
-            for host in groups[group]:
-                hostname = self._get_hostname(host, hostnames)
-                if not hostname:
-                    continue
-                results[group]['hosts'].append(hostname)
-                h = self.inventory.get_host(hostname)
-                results['_meta']['hostvars'][h.name] = h.vars
-        return results
-
     def _add_hosts(self, hosts, group, hostnames):
         '''
             :param hosts: a list of hosts to be added to a group
@@ -573,7 +548,6 @@ class InventoryModule(BaseInventoryPlugin, Constructable, Cacheable):
             cache = self.get_option('cache')
 
         # Generate inventory
-        formatted_inventory = {}
         cache_needs_update = False
         if cache:
             try:
@@ -581,15 +555,13 @@ class InventoryModule(BaseInventoryPlugin, Constructable, Cacheable):
             except KeyError:
                 # if cache expires or cache file doesn't exist
                 cache_needs_update = True
-            else:
-                self._populate_from_source(results)
 
         if not cache or cache_needs_update:
             results = self._query(regions, filters, strict_permissions)
-            self._populate(results, hostnames)
-            formatted_inventory = self._format_inventory(results, hostnames)
+
+        self._populate(results, hostnames)
 
         # If the cache has expired/doesn't exist or if refresh_inventory/flush cache is used
         # when the user is using caching, update the cached inventory
         if cache_needs_update or (not cache and self.get_option('cache')):
-            self.cache.set(cache_key, formatted_inventory)
+            self.cache.set(cache_key, results)