[glance-k8s] enable image-conversion on import

Allow configuring the images to be imported and converted to row.
Disabled by default.

Change-Id: If69f7c0260f45038a58ed0695f71e5559730fc32
Signed-off-by: Guillaume Boutry <guillaume.boutry@canonical.com>

charms/glance-k8s/config.yaml

@@ -252,3 +252,10 @@ options:
       .
       WARNING: this value should only be increased after careful consideration
       and must be set to a value under 8EB (9223372036854775808 bytes).
+  image-conversion:
+    type: boolean
+    default: False
+    description: |
+      Enable conversion of all images to raw format during image import.
+      This only works on imported images (for example using 'openstack image create --import').
+      Does not work on regular image uploads (like 'openstack image create')

charms/glance-k8s/src/charm.py

@@ -21,6 +21,7 @@
 This charm provide Glance services as part of an OpenStack deployment
 """
 
+import json
 import logging
 import re
 from typing import (
@@ -216,6 +217,11 @@ class GlanceConfigContext(sunbeam_ctxts.ConfigContext):
             "image_size_cap": bytes_from_string(
                 self.charm.config["image-size-cap"]
             ),
+            "image_import_plugins": json.dumps(
+                ["image_conversion"]
+                if self.charm.config["image-conversion"]
+                else []
+            ),
         }
 
 
@@ -327,6 +333,12 @@ class GlanceOperatorCharm(sunbeam_charm.OSBaseOperatorAPICharm):
                 self.service_group,
                 0o640,
             ),
+            sunbeam_core.ContainerConfigFile(
+                "/etc/glance/glance-image-import.conf",
+                self.service_user,
+                self.service_group,
+                0o640,
+            ),
             sunbeam_core.ContainerConfigFile(
                 "/usr/local/share/ca-certificates/ca-bundle.pem",
                 self.service_user,

charms/glance-k8s/src/templates/glance-api.conf.j2

@@ -49,4 +49,3 @@ rbd_store_ceph_conf = /etc/ceph/ceph.conf
 flavor = keystone
 
 {% include "parts/section-oslo-messaging-rabbit" %}
-

charms/glance-k8s/src/templates/glance-image-import.conf.j2

@@ -0,0 +1,13 @@
+###############################################################################
+# [ WARNING ]
+# glance configuration file maintained by Juju
+# local changes may be overwritten.
+###############################################################################
+
+[image_import_opts]
+image_import_plugins = {{ glance_config.image_import_plugins }}
+
+{% if "image_conversion" in glance_config.image_import_plugins -%}
+[image_conversion]
+output_format = raw
+{% endif %}