Apply resource versioning to list extractions from etcd

Set the resource version on lists of objects extracted from etcd to prevent
them from always being interpreted as new during updates.

pkg/tools/etcd_tools.go

@@ -140,6 +140,10 @@ func (h *EtcdHelper) ExtractList(key string, slicePtr interface{}) error {
 	for _, node := range nodes {
 		obj := reflect.New(v.Type().Elem())
 		err = h.Codec.DecodeInto([]byte(node.Value), obj.Interface())
+		if h.ResourceVersioner != nil {
+			_ = h.ResourceVersioner.SetResourceVersion(obj.Interface(), node.ModifiedIndex)
+			// being unable to set the version does not prevent the object from being extracted
+		}
 		if err != nil {
 			return err
 		}

pkg/tools/etcd_tools_test.go

@@ -70,30 +70,37 @@ func TestExtractList(t *testing.T) {
 				Nodes: []*etcd.Node{
 					{
 						Value: `{"id":"foo"}`,
+						ModifiedIndex: 1,
 					},
 					{
 						Value: `{"id":"bar"}`,
+						ModifiedIndex: 2,
 					},
 					{
 						Value: `{"id":"baz"}`,
+						ModifiedIndex: 3,
 					},
 				},
 			},
 		},
 	}
 	expect := []api.Pod{
-		{JSONBase: api.JSONBase{ID: "foo"}},
-		{JSONBase: api.JSONBase{ID: "bar"}},
-		{JSONBase: api.JSONBase{ID: "baz"}},
+		{JSONBase: api.JSONBase{ID: "foo", ResourceVersion: 1}},
+		{JSONBase: api.JSONBase{ID: "bar", ResourceVersion: 2}},
+		{JSONBase: api.JSONBase{ID: "baz", ResourceVersion: 3}},
 	}
+
 	var got []api.Pod
 	helper := EtcdHelper{fakeClient, codec, versioner}
 	err := helper.ExtractList("/some/key", &got)
 	if err != nil {
 		t.Errorf("Unexpected error %#v", err)
 	}
-	if !reflect.DeepEqual(got, expect) {
-		t.Errorf("Wanted %#v, got %#v", expect, got)
+
+	for i := 0; i < len(expect); i++ {
+		if !reflect.DeepEqual(got[i], expect[i]) {
+			t.Errorf("\nWanted:\n%#v\nGot:\n%#v\n", expect[i], got[i])
+		}
 	}
 }