ec2_group: description property is immutable (#19790)

* update integration tests for updated boto exception message

* integration tests fail on both "test credential" test cases

exception bubbles out of module.  instead catch and wrap

* ec2_group does not support updating a security group's description

AWS security group descriptions are immutable.
if ec2_group finds a group that matches by name, but the descriptions do not match, the module does not support this case
previously it would check if the group was used, but would not do anything if it was

old behavior was erroneous because it could make a user expect that the description change of a group was fine when in fact it did not occur
also, it made an expensive check against all ec2 instances for no good reason

* comments not doc strings

* else must have pass w/o doc-string statement

* Catch specific BotoServerException, give context around error when fetching SGs

* python3 compatible exception blocks

* add traceback to fail_json

* two blank lines before first function

lib/ansible/modules/cloud/amazon/ec2_group.py

@@ -140,10 +140,13 @@ EXAMPLES = '''
 try:
     import boto.ec2
     from boto.ec2.securitygroup import SecurityGroup
+    from boto.exception import BotoServerError
     HAS_BOTO = True
 except ImportError:
     HAS_BOTO = False
 
+import traceback
+
 
 def make_rule_key(prefix, rule, group_id, cidr_ip):
     """Creates a unique key for an individual group rule"""
@@ -283,7 +286,13 @@ def main():
     # find the group if present
     group = None
     groups = {}
-    for curGroup in ec2.get_all_security_groups():
+
+    try:
+        security_groups = ec2.get_all_security_groups()
+    except BotoServerError as e:
+        module.fail_json(msg="Error in get_all_security_groups: %s" % e.message, exception=traceback.format_exc())
+
+    for curGroup in security_groups:
         groups[curGroup.id] = curGroup
         if curGroup.name in groups:
             # Prioritise groups from the current VPC
@@ -298,36 +307,29 @@ def main():
     # Ensure requested group is absent
     if state == 'absent':
         if group:
-            '''found a match, delete it'''
+            # found a match, delete it
             try:
                 if not module.check_mode:
                     group.delete()
-            except Exception as e:
-                module.fail_json(msg="Unable to delete security group '%s' - %s" % (group, e))
+            except BotoServerError as e:
+                module.fail_json(msg="Unable to delete security group '%s' - %s" % (group, e.message), exception=traceback.format_exc())
             else:
                 group = None
                 changed = True
         else:
-            '''no match found, no changes required'''
+            # no match found, no changes required
+            pass
 
     # Ensure requested group is present
     elif state == 'present':
         if group:
-            '''existing group found'''
-            # check the group parameters are correct
-            group_in_use = False
-            rs = ec2.get_all_instances()
-            for r in rs:
-                for i in r.instances:
-                    group_in_use |= reduce(lambda x, y: x | (y.name == 'public-ssh'), i.groups, False)
-
+            # existing group
             if group.description != description:
-                if group_in_use:
-                    module.fail_json(msg="Group description does not match, but it is in use so cannot be changed.")
+                module.fail_json(msg="Group description does not match existing group. ec2_group does not support this case.")
 
         # if the group doesn't exist, create it now
         else:
-            '''no match found, create it'''
+            # no match found, create it
             if not module.check_mode:
                 group = ec2.create_security_group(name, description, vpc_id=vpc_id)
 

test/integration/roles/test_ec2_group/tasks/main.yml

@@ -74,7 +74,7 @@
   assert:
     that:
        - 'result.failed'
-       - 'result.msg.startswith("value of region must be one of:")'
+       - 'result.msg.startswith("Region asdf querty 1234 does not seem to be available for aws module boto.ec2. If the region definitely exists, you may need to upgrade boto or extend with endpoints_path")'
 
 # ============================================================
 - name: test valid region parameter
@@ -155,7 +155,7 @@
   assert:
     that:
        - 'result.failed'
-       - '"EC2ResponseError: 401 Unauthorized" in result.msg'
+       - '"Error in get_all_security_groups: AWS was not able to validate the provided access credentials" in result.msg'
 
 # ============================================================
 - name: test credential parameters
@@ -172,7 +172,7 @@
   assert:
     that:
        - 'result.failed'
-       - '"EC2ResponseError: 401 Unauthorized" in result.msg'
+       - '"Error in get_all_security_groups: AWS was not able to validate the provided access credentials" in result.msg'
 
 # ============================================================
 - name: test state=absent
@@ -207,6 +207,24 @@
        - 'result.changed'
        - 'result.group_id.startswith("sg-")'
 
+# ============================================================
+- name: test state=present different description raises error
+  ec2_group:
+    name='{{ec2_group_name}}'
+    description='{{ec2_group_description}}CHANGED'
+    ec2_region='{{ec2_region}}'
+    ec2_access_key='{{ec2_access_key}}'
+    ec2_secret_key='{{ec2_secret_key}}'
+    state=present
+  ignore_errors: true
+  register: result
+
+- name: assert matching group with non-matching description raises error
+  assert:
+    that:
+       - 'result.failed'
+       - '"Group description does not match existing group. ec2_group does not support this case." in result.msg'
+
 # ============================================================
 - name: test state=present (expected changed=false)
   ec2_group: