hostgroup: Reduce addition and deletion of members to changed only

Use gen_add_list and gen_intersection_list for host, hostgroup,
membermanager_user and membermanager_group member handling.

The functions are used to reduce the add lists to the new entries
only and the delete lists to the entries that are in the user and
the show list result.

This enables to remove the ignores for "already a member" and
"not a member" errors..

plugins/modules/ipahostgroup.py

@@ -141,7 +141,8 @@ RETURN = """
 from ansible.module_utils.basic import AnsibleModule
 from ansible.module_utils.ansible_freeipa_module import temp_kinit, \
     temp_kdestroy, valid_creds, api_connect, api_command, compare_args_ipa, \
-    module_params_get, gen_add_del_lists, api_check_command, api_check_param
+    module_params_get, gen_add_del_lists, api_check_command, api_check_param, \
+    gen_add_list, gen_intersection_list
 
 
 def find_hostgroup(module, name):
@@ -396,6 +397,15 @@ def main():
                         ansible_module.fail_json(
                             msg="No hostgroup '%s'" % name)
 
+                    # Reduce add lists for member_host and member_hostgroup,
+                    # to new entries only that are not in res_find.
+                    if host is not None and "member_host" in res_find:
+                        host = gen_add_list(host, res_find["member_host"])
+                    if hostgroup is not None \
+                       and "member_hostgroup" in res_find:
+                        hostgroup = gen_add_list(
+                            hostgroup, res_find["member_hostgroup"])
+
                     # Ensure members are present
                     commands.append([name, "hostgroup_add_member",
                                      {
@@ -404,6 +414,20 @@ def main():
                                      }])
 
                     if has_add_membermanager:
+                        # Reduce add list for membermanager_user and
+                        # membermanager_group to new entries only that are
+                        # not in res_find.
+                        if membermanager_user is not None \
+                           and "membermanager_user" in res_find:
+                            membermanager_user = gen_add_list(
+                                membermanager_user,
+                                res_find["membermanager_user"])
+                        if membermanager_group is not None \
+                           and "membermanager_group" in res_find:
+                            membermanager_group = gen_add_list(
+                                membermanager_group,
+                                res_find["membermanager_group"])
+
                         # Add membermanager users and groups
                         if membermanager_user is not None or \
                            membermanager_group is not None:
@@ -441,6 +465,15 @@ def main():
                         ansible_module.fail_json(
                             msg="No hostgroup '%s'" % name)
 
+                    # Reduce del lists of member_host and member_hostgroup,
+                    # to the entries only that are in res_find.
+                    if host is not None:
+                        host = gen_intersection_list(
+                            host, res_find.get("member_host"))
+                    if hostgroup is not None:
+                        hostgroup = gen_intersection_list(
+                            hostgroup, res_find.get("member_hostgroup"))
+
                     # Ensure members are absent
                     commands.append([name, "hostgroup_remove_member",
                                      {
@@ -449,6 +482,18 @@ def main():
                                      }])
 
                     if has_add_membermanager:
+                        # Reduce del lists of membermanager_user and
+                        # membermanager_group to the entries only that are
+                        # in res_find.
+                        if membermanager_user is not None:
+                            membermanager_user = gen_intersection_list(
+                                membermanager_user,
+                                res_find.get("membermanager_user"))
+                        if membermanager_group is not None:
+                            membermanager_group = gen_intersection_list(
+                                membermanager_group,
+                                res_find.get("membermanager_group"))
+
                         # Remove membermanager users and groups
                         if membermanager_user is not None or \
                            membermanager_group is not None:
@@ -487,9 +532,6 @@ def main():
                 failed = result["failed"][failed_item]
                 for member_type in failed:
                     for member, failure in failed[member_type]:
-                        if "already a member" in failure \
-                           or "not a member" in failure:
-                            continue
                         errors.append("%s: %s %s: %s" % (
                             command, member_type, member, failure))
             if len(errors) > 0: