redis: use regexp to check if the value matches expected form (#1079) (#1129)

* Use regexp to check if the value matches expected form

regexp should match values like:
- 1B
- 10MB
- 10mb

* Added changelog entry

* Update changelogs/fragments/1079-redis-use-regexp-to-check-if-the-value-matches-expected-form.yaml

Co-authored-by: Amin Vakil <info@aminvakil.com>

Co-authored-by: Amin Vakil <info@aminvakil.com>
(cherry picked from commit bcfd648855)

Co-authored-by: Robbert Müller <mjrider@users.noreply.github.com>

changelogs/fragments/1079-redis-use-regexp-to-check-if-the-value-matches-expected-form.yaml

@@ -0,0 +1,2 @@
+bugfixes:
+  - redis - fixes parsing of config values which should not be converted to bytes (https://github.com/ansible-collections/community.general/pull/1079).

plugins/modules/database/misc/redis.py

@@ -131,6 +131,7 @@ else:
 from ansible.module_utils.basic import AnsibleModule, missing_required_lib
 from ansible.module_utils.common.text.formatters import human_to_bytes
 from ansible.module_utils._text import to_native
+import re
 
 
 # Redis module specific support methods.
@@ -277,7 +278,10 @@ def main():
         name = module.params['name']
 
         try:  # try to parse the value as if it were the memory size
-            value = str(human_to_bytes(module.params['value'].upper()))
+            if re.match(r'^\s*(\d*\.?\d*)\s*([A-Za-z]+)?\s*$', module.params['value'].upper()):
+                value = str(human_to_bytes(module.params['value'].upper()))
+            else:
+                value = module.params['value']
         except ValueError:
             value = module.params['value']