Ensure removed web console extension variables are not set

roles/openshift_sanitize_inventory/tasks/main.yml

@@ -77,6 +77,18 @@
         openshift_cloudprovider_vsphere_host is undefined or openshift_cloudprovider_vsphere_datacenter is undefined or
         openshift_cloudprovider_vsphere_datastore is undefined )
 
+- name: Ensure removed web console extension variables are not set
+  fail:
+    msg: >
+      The OpenShift web console extensions must now be served as URLs. You can
+      add extensions using the openshift_web_console_extension_script_urls
+      and openshift_web_console_extension_stylesheet_urls variables. The
+      following variables are no longer used: openshift_master_extension_scripts,
+      openshift_master_extension_stylesheets, openshift_master_extensions
+  when:
+    - openshift_master_extension_scripts is defined or openshift_master_extension_stylesheets is defined or openshift_master_extensions is defined
+    - openshift_version | version_compare('3.9', '>=')
+
 - name: Ensure that web console port matches API server port
   fail:
     msg: >