zypper_repository: handle repositories without <url/> element (#10225)

* zypper_repository: handle repositories without <url/> element

zypper_repository identifies repos using a combination of "alias"
and "url". Recently, openSUE has begun using "metalink" attributes
instead of "url" elements, causing errors like this:

  File "/tmp/ansible_zypper_repository_payload_euim_nod/ansible_zypper_repository_payload.zip/ansible_collections/community/general/plugins/modules/zypper_repository.py", line 475, in <module>
  File "/tmp/ansible_zypper_repository_payload_euim_nod/ansible_zypper_repository_payload.zip/ansible_collections/community/general/plugins/modules/zypper_repository.py", line 448, in main
  File "/tmp/ansible_zypper_repository_payload_euim_nod/ansible_zypper_repository_payload.zip/ansible_collections/community/general/plugins/modules/zypper_repository.py", line 223, in repo_exists
  File "/tmp/ansible_zypper_repository_payload_euim_nod/ansible_zypper_repository_payload.zip/ansible_collections/community/general/plugins/modules/zypper_repository.py", line 177, in _parse_repos
IndexError: list index out of range

Fix this by using the "metalink" attribute instead of the value
of the "url" element if the latter is missing.

* Update changelogs/fragments/10224-zypper_repository-metalink.yml

Co-authored-by: Felix Fontein <felix@fontein.de>

---------

Co-authored-by: Felix Fontein <felix@fontein.de>

changelogs/fragments/10224-zypper_repository-metalink.yml

@@ -0,0 +1,2 @@
+bugfixes:
+  - zypper_repository - use ``metalink`` attribute to identify repositories without ``<url/>`` element (https://github.com/ansible-collections/community.general/issues/10224, https://github.com/ansible-collections/community.general/pull/10225).

plugins/modules/zypper_repository.py

@@ -174,7 +174,10 @@ def _parse_repos(module):
             opts = {}
             for o in REPO_OPTS:
                 opts[o] = repo.getAttribute(o)
-            opts['url'] = repo.getElementsByTagName('url')[0].firstChild.data
+            try:
+                opts['url'] = repo.getElementsByTagName('url')[0].firstChild.data
+            except IndexError:
+                opts['url'] = repo.getAttribute('metalink')
             # A repo can be uniquely identified by an alias + url
             repos.append(opts)
         return repos