Expose placement exception code to end users

Attempting to create an existing host already in DB resulted in a 409
Conflict response status code in the Rocky release. However, on the
current master, using the placement API support has changed it to return
a 500 Internal Server Error.

This patch changes it back to 409 by bubbling up the exception code
occured in the placement resource provider creation.

Change-Id: I5c02a8fe9a83adf83358062fcc5470e38e643550
Closes-Bug: #1812642

blazar/api/v1/utils.py

@@ -26,6 +26,7 @@ from blazar.db import exceptions as db_exceptions
 from blazar import exceptions as ex
 from blazar.i18n import _
 from blazar.manager import exceptions as manager_exceptions
+from blazar.utils.openstack import exceptions as opst_exceptions
 
 LOG = logging.getLogger(__name__)
 
@@ -88,6 +89,8 @@ class Rest(flask.Blueprint):
                         # Get the exception from manager and common exceptions
                         cls = getattr(manager_exceptions, e.exc_type,
                                       getattr(ex, e.exc_type, None))
+                        cls = cls or getattr(opst_exceptions, e.exc_type,
+                                             getattr(ex, e.exc_type, None))
                         if cls is not None:
                             return render_error_message(cls.code, e.value,
                                                         cls.code)

blazar/utils/openstack/exceptions.py

@@ -23,6 +23,11 @@ class ResourceProviderCreationFailed(exceptions.BlazarException):
     msg_fmt = _("Failed to create resource provider %(name)s")
 
 
+class ResourceProviderCreationConflict(exceptions.BlazarException):
+    code = 409
+    msg_fmt = _("Conflict on creating resource provider %(name)s ")
+
+
 class ResourceProviderDeletionFailed(exceptions.BlazarException):
     msg_fmt = _("Failed to delete resource provider %(uuid)s")
 

blazar/utils/openstack/placement.py

@@ -148,6 +148,17 @@ class BlazarPlacementClient(object):
             LOG.info(msg, args)
             return resp.json()
 
+        if resp.status_code == 409:
+            msg = ("Conflict on creating resource provider %(name)s in "
+                   "placement API. Got %(status_code)d: %(err_text)s.")
+            args = {
+                'name': rp_name,
+                'status_code': resp.status_code,
+                'err_text': resp.text,
+            }
+            LOG.error(msg, args)
+            raise exceptions.ResourceProviderCreationConflict(name=rp_name)
+
         msg = ("Failed to create resource provider record in placement API "
                "for resource provider %(name)s. "
                "Got %(status_code)d: %(err_text)s.")