oslo_config_validator: Adding possibility to override namespaces config

It might be a good idea to override specific namespace config from
the playbook as it gives more flexibility to operators when it's time
to validate settings. This commit adds the option to have a namespaces
config override that will override the default namespace configs.

Change-Id: I3fb67afb25c8bb3185ad8febd8fa8257bcb4085f

playbooks/oslo-config-validator.yaml

@@ -29,6 +29,21 @@
         - identity
       products:
         - tripleo
+
+    # Overriding simple namespaces config can be done on a per-namespace basis.
+    # We simply need to add a dict to this list of dictionnary. It will replace
+    # its corresponding entry from the default config
+    # This is usefull if we want to target the validation on a set of hosts
+    # that would otherwise trigger an error.
+    # oslo_config_validator_namespaces_config_override:
+    #   - namespace: nova.conf
+    #     invalid_settings:
+    #       - section: filter_scheduler
+    #         option: enabled_filters
+    #         separator: ","
+    #         value_list:
+    #           - SomeBadFilter
+
     # Debug log level
     oslo_config_validator_debug: false
 
@@ -68,5 +83,6 @@
       - placement
       - neutron
       - keystone
+
   roles:
     - oslo_config_validator

roles/oslo_config_validator/tasks/build_validation_config.yml

@@ -44,6 +44,24 @@
   debug:
     var: service_config
 
+- name: Overriding namespace configuration
+  set_fact:
+    namespaces_config: >-
+      {% set override_config = [] %}{%
+         for config in oslo_config_validator_namespaces_config | default([]) %}{%
+           set _ = override_config.append(
+             oslo_config_validator_namespaces_config_override | default([]) |
+             selectattr('namespace', 'eq', config.namespace) | first | default(config, true)
+           ) %}{%
+         endfor %}{{
+       override_config }}
+
+- name: Printing overriden namespace config
+  when:
+    - oslo_config_validator_debug | bool
+  debug:
+    var: namespaces_config
+
 - name: podman - Gather facts for all containers
   become: true
   containers.podman.podman_container_info:
@@ -133,7 +151,7 @@
             %}{%
                if svc_config | count %}{%
                  for ns in svc_config[0].namespaces | list %}{%
-                   set ns_config = oslo_config_validator_namespaces_config |
+                   set ns_config = namespaces_config |
                                    selectattr('namespace', 'equalto', ns) |
                                    selectattr('invalid_settings', 'defined') | list %}{%
                    if ns_config | count %}{%

roles/oslo_config_validator/tasks/validate_config.yml

@@ -42,7 +42,7 @@
   set_fact:
     validation_output: >-
       {% set ignored_patterns = oslo_config_validator_global_ignored_messages | default("") %}{%
-         for ns in oslo_config_validator_namespaces_config | default([]) %}{%
+         for ns in namespaces_config | default([]) %}{%
            if ns.namespace in out.config_file.namespaces %}{%
              for ignored in ns.ignored_messages | default([]) %}{%
                set _ = ignored_patterns.append(ignored) %}{%