Fix that get of host config returned nil instead of error. (#339)

lib/backend/k8s/k8s.go

@@ -1,4 +1,4 @@
-// Copyright (c) 2016 Tigera, Inc. All rights reserved.
+// Copyright (c) 2016-2017 Tigera, Inc. All rights reserved.
 
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -718,10 +718,7 @@ func (c *KubeClient) deleteGlobalConfig(k *model.KVPair) error {
 }
 
 func (c *KubeClient) getHostConfig(k model.HostConfigKey) (*model.KVPair, error) {
-	return &model.KVPair{
-		Key:   k,
-		Value: nil,
-	}, nil
+	return nil, errors.ErrorResourceDoesNotExist{Identifier: k}
 }
 
 func (c *KubeClient) listHostConfig(l model.HostConfigListOptions) ([]*model.KVPair, error) {

lib/backend/k8s/k8s_fv_test.go

@@ -1,3 +1,17 @@
+// Copyright (c) 2016-2017 Tigera, Inc. All rights reserved.
+
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
 package k8s
 
 import (
@@ -10,6 +24,7 @@ import (
 	log "github.com/Sirupsen/logrus"
 	"github.com/projectcalico/libcalico-go/lib/backend/api"
 	"github.com/projectcalico/libcalico-go/lib/backend/model"
+	"github.com/projectcalico/libcalico-go/lib/errors"
 	cnet "github.com/projectcalico/libcalico-go/lib/net"
 	k8sapi "k8s.io/client-go/pkg/api/v1"
 	extensions "k8s.io/client-go/pkg/apis/extensions/v1beta1"
@@ -344,6 +359,12 @@ var _ = Describe("Test Syncer API for Kubernetes backend", func() {
 		Expect(len(objs)).To(Equal(0))
 	})
 
+	It("should report ErrorResourceDoesNotExist for HostConfig", func() {
+		kv, err := c.Get(model.HostConfigKey{Hostname: "host", Name: "foo"})
+		Expect(kv).To(BeNil())
+		Expect(err).To(BeAssignableToTypeOf(errors.ErrorResourceDoesNotExist{}))
+	})
+
 	It("should support setting and getting GlobalConfig", func() {
 		gc := &model.KVPair{
 			Key: model.GlobalConfigKey{