Add option region_name to s3 store

The current s3 driver determine region_name from amazon endpoints, but
some operators are using an s3 compatible API which is not from amazon.
Adding a region_name paramater to the s3 store allow such operators to
use custom endpoints with custom regions.

Signed-off-by: Arnaud Morin <arnaud.morin@ovhcloud.com>
Change-Id: I8ce4d83a470eb5c87527db7ffacb9d0b2302b661

specs/2023.1/approved/glance_store/add-region_name-s3.rst

@@ -0,0 +1,28 @@
+..
+ This work is licensed under a Creative Commons Attribution 3.0 Unported
+ License.
+
+ http://creativecommons.org/licenses/by/3.0/legalcode
+
+================================================
+Spec Lite: Add region_name parameter to s3 store
+================================================
+
+:project: glance_store
+
+:problem: The current s3 driver determine region_name from amazon endpoints,
+          but some operators are using an s3 compatible API which is not from
+          amazon.
+          In such situation, the region_name parameter cannot be guessed from
+          endpoints and result beeing set to None.
+          When region_name=None is given to instanciate the s3 client, the
+          internal boto3 code is then using a default region_name which is
+          wrong (like us-west-1).
+
+:solution: We need to add a new parameter s3_store_region_name in glance
+           config so that we can use this value instead of guessing it from
+           s3_store_host.
+
+:impacts: None
+
+:assignee: Arnaud Morin <arnaud.morin@ovhcloud.com>

specs/2023.1/approved/index.rst

@@ -6,7 +6,13 @@
    :glob:
    :maxdepth: 1
 
-TODO: fill this in until a new approved space is added.
+2023.1 approved specs for glance store:
+
+.. toctree::
+    :glob:
+    :maxdepth: 1
+
+    glance_store/*