Fix talking to older servers

joker-at-work · joker-at-work · commit 59824da6c710 · 2025-07-14T08:52:39.000+02:00
Cinderclient currently supports version 3.71 as defined in
`cinderclient.api_versions.MAX_VERSION`. When doing version discovery,
we create a temporary client with the MAX_VERSION and use this client to
fetch the available versions. If the server doesn't support 3.71, yet,
the version discovery request fails with:

	cinderclient.exceptions.NotAcceptable: Version 3.71 is not supported by the API. Minimum is 3.0 and maximum is 3.70. (HTTP 406)
	ERROR: Version 3.71 is not supported by the API. Minimum is 3.0 and maximum is 3.70. (HTTP 406)

To fix this, we instead create a client with the MIN_VERSION, because
the versions endpoint should be available there already.

NOTE: Even when specifying an `--os-volume-api-version 3.70` the request
fails, because version discovery still takes place in case we have to
downgrade from the requested version.

Change-Id: I38b71cea6b92da7f451e2a02d55900fe18e9aab0
Signed-off-by: Johannes Kulik &lt;johannes.kulik@sap.com&gt;
Closes-Bug: #1998596
diff --git a/cinderclient/shell.py b/cinderclient/shell.py
@@ -771,11 +771,11 @@ def main(self, argv):
                         "using --os-volume-api-version option.")
                 raise exc.UnsupportedVersion(msg)
 
-        API_MAX_VERSION = api_versions.APIVersion(api_versions.MAX_VERSION)
+        API_MIN_VERSION = api_versions.APIVersion(api_versions.MIN_VERSION)
         # FIXME: the endpoint_api_version[0] can ONLY be '3' now, so the
         # above line should probably be ripped out and this condition removed
         if endpoint_api_version[0] == '3':
-            disc_client = client.Client(API_MAX_VERSION,
+            disc_client = client.Client(API_MIN_VERSION,
                                         os_username,
                                         os_password,
                                         os_project_name,
@@ -840,9 +840,9 @@ def _discover_client(self,
         if not os_service_type:
             os_service_type = self._discover_service_type(discovered_version)
 
-        API_MAX_VERSION = api_versions.APIVersion(api_versions.MAX_VERSION)
+        API_MIN_VERSION = api_versions.APIVersion(api_versions.MIN_VERSION)
 
-        if (discovered_version != API_MAX_VERSION or
+        if (discovered_version != API_MIN_VERSION or
                 os_service_type != 'volume' or
                 os_endpoint_type != DEFAULT_CINDER_ENDPOINT_TYPE):
             client_args['service_type'] = os_service_type
diff --git a/releasenotes/notes/bug-1998596-5cac70cc68b3d6a5.yaml b/releasenotes/notes/bug-1998596-5cac70cc68b3d6a5.yaml
@@ -0,0 +1,6 @@
+---
+fixes:
+  - |
+    `Bug #1998596 <https://bugs.launchpad.net/python-cinderclient/+bug/1998596>`_:
+    fixed version discovery if the server was older than the maximum supported
+    version defined in python-cinderclient.
