Ignore unrelated error labels in request handler

Nodepool was declining node requests when other unrelated instance types
of a provider were unavailable:

    Declining node request <NodeRequest {... 'node_types': ['ubuntu'],
    ... }> due to ['node type(s) [ubuntu-invalid] not available']

To fix this we will the check error labels against the requested labels
before including them in the list of invalid node types.

Change-Id: I7bbb3b813ca82baf80821a9e84cc10385ea95a01

nodepool/driver/__init__.py

@@ -429,7 +429,8 @@ class NodeRequestHandler(NodeRequestHandlerNotifications,
             if ntype not in valid:
                 invalid.add(ntype)
         for ntype in self.manager.errorLabels():
-            invalid.add(ntype)
+            if ntype in self.request.node_types:
+                invalid.add(ntype)
         return invalid
 
     def _waitForNodeSet(self):

nodepool/tests/fixtures/aws/aws-invalid.yaml

@@ -13,6 +13,7 @@ tenant-resource-limits:
     max-cores: 1024
 
 labels:
+  - name: ubuntu-invalid
   - name: ubuntu
 
 providers:
@@ -32,7 +33,11 @@ providers:
           key1: value1
           key2: value2
         labels:
-          - name: ubuntu
+          - name: ubuntu-invalid
             cloud-image: ubuntu
             instance-type: t3.nope
             key-name: zuul
+          - name: ubuntu
+            cloud-image: ubuntu
+            instance-type: t3.medium
+            key-name: zuul

nodepool/tests/unit/test_driver_aws.py

@@ -756,10 +756,21 @@ class TestDriverAws(tests.DBTestCase):
         self.assertTrue(response['EbsOptimized']['Value'])
 
     def test_aws_invalid_instance_type(self):
-        req = self.requestNode('aws/aws-invalid.yaml', 'ubuntu')
+        req = self.requestNode('aws/aws-invalid.yaml', 'ubuntu-invalid')
         self.assertEqual(req.state, zk.FAILED)
         self.assertEqual(req.nodes, [])
 
+        # Make sure other instance types are not affected
+        req = zk.NodeRequest()
+        req.state = zk.REQUESTED
+        req.tenant_name = 'tenant-1'
+        req.node_types.append('ubuntu')
+        self.zk.storeNodeRequest(req)
+
+        req = self.waitForNodeRequest(req)
+        self.assertEqual(req.state, zk.FULFILLED)
+        self.assertEqual(len(req.nodes), 1)
+
     def test_aws_diskimage_snapshot(self):
         self.fake_aws.fail_import_count = 1
         configfile = self.setup_config('aws/diskimage.yaml')