inventory plugins - Hard code fall-back region to connect to when try…

…ing to pull a list of regions (#1552) (#1556)

[PR #1552/c9920701 backport][stable-6] inventory plugins - Hard code fall-back region to connect to when trying to pull a list of regions

This is a backport of PR #1552 as merged into main (c992070).
SUMMARY
fixes: #1551
If no regions and no region is provided, then botocore will sometimes refuse to connect to the EC2 endpoint for us to then pull a list of regions...
ISSUE TYPE

Bugfix Pull Request

COMPONENT NAME
aws_ec2 inventory plugin
ADDITIONAL INFORMATION
Nominally botocore should be falling back to a default region, but there are no guarantees

Reviewed-by: Mark Chappell

changelogs/fragments/1551-ec2_inventory-no-region.yml

@@ -0,0 +1,2 @@
+bugfixes:
+- aws_ec2 inventory plugin - fix ``NoRegionError`` when no regions are provided and region isn't specified (https://github.com/ansible-collections/amazon.aws/issues/1551).

plugins/plugin_utils/inventory.py

@@ -117,7 +117,8 @@ def _set_frozen_credentials(self):
     def _describe_regions(self, service):
         # Try pulling a list of regions from the service
         try:
-            client = self.client(service)
+            initial_region = self.region or "us-east-1"
+            client = self.client(service, region=initial_region)
             resp = client.describe_regions()
         except AttributeError:
             # Not all clients support describe

tests/integration/targets/inventory_aws_ec2/aliases

@@ -1,3 +1,3 @@
-time=10m
+time=15m
 
 cloud/aws