From dc85c089702a9819fdab7c951d427de838a3dcc6 Mon Sep 17 00:00:00 2001
From: Chris Dent <cdent@anticdent.org>
Date: Sat, 15 Jul 2017 18:49:57 +0100
Subject: [PATCH] [placement] fix 500 error when allocating to bad class

Adjust exception handling when calling set_allocations so that a
KeyError in the usage_map raises an InvalidInventory. When making
allocations against a resource provider with >1 resource classes
and where one of those resource classes does not have inventory on the
provider, we can attempt to get info out of the usage_map that is not
there, and get a KeyError. This catches the KeyError and turns it into
an InvalidInventory which eventually results in a 409 response,
consistent with other responses to bad allocations. Since this is fixing
a 500, no microversion required.

NOTE(mriedem): The functional test required some tweaks for Ocata since
we didn't have the 1.7 microversion in Ocata. In addition, inventories
in early days required that max_unit be set, otherwise it would default
to 0 and no allocations could be made. We might wish to consider that a
bug in older versions that we should fix?

Change-Id: I52fa02b56f8e62dfa206a3969a99fab250508760
Closes-Bug: #1704574
(cherry picked from commit 913149249cc00f50a6219d3ddc86f3600a610c00)
---
 nova/objects/resource_provider.py             |  8 +-
 .../gabbits/allocation-bad-class.yaml         | 75 +++++++++++++++++++
 2 files changed, 82 insertions(+), 1 deletion(-)
 create mode 100644 nova/tests/functional/api/openstack/placement/gabbits/allocation-bad-class.yaml

diff --git a/nova/objects/resource_provider.py b/nova/objects/resource_provider.py
index 79c9af7131f2..feebbda84944 100644
--- a/nova/objects/resource_provider.py
+++ b/nova/objects/resource_provider.py
@@ -1032,7 +1032,13 @@ def _check_capacity_exceeded(conn, allocs):
         rc_id = _RC_CACHE.id_from_string(alloc.resource_class)
         rp_uuid = alloc.resource_provider.uuid
         key = (rp_uuid, rc_id)
-        usage = usage_map[key]
+        try:
+            usage = usage_map[key]
+        except KeyError:
+            # The resource class at rc_id is not in the usage map.
+            raise exception.InvalidInventory(
+                    resource_class=alloc.resource_class,
+                    resource_provider=rp_uuid)
         amount_needed = alloc.used
         allocation_ratio = usage['allocation_ratio']
         min_unit = usage['min_unit']
diff --git a/nova/tests/functional/api/openstack/placement/gabbits/allocation-bad-class.yaml b/nova/tests/functional/api/openstack/placement/gabbits/allocation-bad-class.yaml
new file mode 100644
index 000000000000..c91884f0a41d
--- /dev/null
+++ b/nova/tests/functional/api/openstack/placement/gabbits/allocation-bad-class.yaml
@@ -0,0 +1,75 @@
+
+fixtures:
+    - APIFixture
+
+defaults:
+    request_headers:
+        x-auth-token: admin
+        accept: application/json
+        content-type: application/json
+        OpenStack-API-Version: placement latest
+
+tests:
+
+- name: create a resource provider
+  POST: /resource_providers
+  data:
+      name: an rp
+  status: 201
+
+- name: get resource provider
+  GET: $LOCATION
+  status: 200
+
+- name: create a resource class
+  POST: /resource_classes
+  request_headers:
+    content-type: application/json
+  data:
+      name: CUSTOM_GOLD
+  status: 201
+
+- name: add inventory to an rp
+  PUT: /resource_providers/$HISTORY['get resource provider'].$RESPONSE['$.uuid']/inventories
+  data:
+      resource_provider_generation: 0
+      inventories:
+          VCPU:
+              total: 24
+              max_unit: 9999
+          CUSTOM_GOLD:
+              total: 5
+              max_unit: 9999
+  status: 200
+
+- name: allocate some of it two
+  desc: this is the one that used to raise a 500
+  PUT: /allocations/6d9f83db-6eb5-49f6-84b0-5d03c6aa9fc8
+  data:
+      allocations:
+          - resource_provider:
+                uuid: $HISTORY['get resource provider'].$RESPONSE['$.uuid']
+            resources:
+                DISK_GB: 5
+                CUSTOM_GOLD: 1
+  status: 409
+
+- name: allocate some of it custom
+  PUT: /allocations/6d9f83db-6eb5-49f6-84b0-5d03c6aa9fc8
+  data:
+      allocations:
+          - resource_provider:
+                uuid: $HISTORY['get resource provider'].$RESPONSE['$.uuid']
+            resources:
+                CUSTOM_GOLD: 1
+  status: 204
+
+- name: allocate some of it standard
+  PUT: /allocations/6d9f83db-6eb5-49f6-84b0-5d03c6aa9fc8
+  data:
+      allocations:
+          - resource_provider:
+                uuid: $HISTORY['get resource provider'].$RESPONSE['$.uuid']
+            resources:
+                DISK_GB: 1
+  status: 409