Support configurable dogpile cache expiration

The [cache]/expiration_time currently caches items for the default
of 600s and is not configurable via the charm. This change adds a
dogpile-cache-expiration config option that will default to 600s
so as not to cause any behavior changes by default.

Closes-Bug: #1899117
Change-Id: I639b2b77d5db69744897b6798613a797d05fe23b
Co-authored-by: Chris MacNaughton <chris.macnaughton@canonical.com>

config.yaml

@@ -107,6 +107,13 @@ options:
     type: int
     default: 60
     description: Amount of time (in seconds) the catalog should be cached for.
+  dogpile-cache-expiration:
+    type: int
+    default: 600
+    description: |
+      Amount of time (in seconds) to cache items in the dogpile.cache. This
+      only applies to cached methods that do not have an explicitly defined
+      cache expiration time.
   fernet-max-active-keys:
     type: int
     default: 3

hooks/keystone_context.py

@@ -202,6 +202,7 @@ class KeystoneContext(context.OSContextGenerator):
         ctxt['verbose'] = config('verbose')
         ctxt['token_expiration'] = config('token-expiration')
         ctxt['catalog_cache_expiration'] = config('catalog-cache-expiration')
+        ctxt['dogpile_cache_expiration'] = config('dogpile-cache-expiration')
 
         ctxt['identity_backend'] = config('identity-backend')
         ctxt['assignment_backend'] = config('assignment-backend')

templates/mitaka/keystone.conf

@@ -51,6 +51,9 @@ expiration = {{ token_expiration }}
 {% include "parts/section-signing" %}
 
 {% include "section-oslo-cache" %}
+# This goes in the section above, selectively
+# Bug #1899117
+expiration_time = {{ dogpile_cache_expiration }}
 
 [policy]
 driver = sql
@@ -112,3 +115,4 @@ admin_project_name = admin
 # This goes in the section above, selectively
 # Bug #1819134
 max_request_body_size = 114688
+

templates/ocata/keystone.conf

@@ -60,6 +60,9 @@ max_active_keys = {{ fernet_max_active_keys }}
 {% include "parts/section-signing" %}
 
 {% include "section-oslo-cache" %}
+# This goes in the section above, selectively
+# Bug #1899117
+expiration_time = {{ dogpile_cache_expiration }}
 
 [policy]
 driver = sql
@@ -134,3 +137,4 @@ admin_project_name = admin
 # This goes in the section above, selectively
 # Bug #1819134
 max_request_body_size = 114688
+

templates/queens/keystone.conf

@@ -59,6 +59,9 @@ max_active_keys = {{ fernet_max_active_keys }}
 {% include "parts/section-signing" %}
 
 {% include "section-oslo-cache" %}
+# This goes in the section above, selectively
+# Bug #1899117
+expiration_time = {{ dogpile_cache_expiration }}
 
 [policy]
 driver = sql
@@ -133,3 +136,4 @@ admin_project_name = admin
 # This goes in the section above, selectively
 # Bug #1819134
 max_request_body_size = 114688
+

templates/rocky/keystone.conf

@@ -50,6 +50,9 @@ max_active_keys = {{ fernet_max_active_keys }}
 {% include "parts/section-signing" %}
 
 {% include "section-oslo-cache" %}
+# This goes in the section above, selectively
+# Bug #1899117
+expiration_time = {{ dogpile_cache_expiration }}
 
 [policy]
 driver = sql
@@ -117,3 +120,4 @@ admin_project_name = admin
 # This goes in the section above, selectively
 # Bug #1819134
 max_request_body_size = 114688
+