fix func name and use extracExprs

Signed-off-by: Xian Chaobo <xianchaobo@huawei.com>

cluster/config.go

@@ -147,13 +147,10 @@ func (c *ContainerConfig) Constraints() []string {
 	return c.extractExprs("constraints")
 }
 
-// AddSoftImageAffinity to config
+// AddAffinity to config
-func (c *ContainerConfig) AddSoftImageAffinity(image string) error {
+func (c *ContainerConfig) AddAffinity(affinity string) error {
-	affnitiesJSON := c.Labels[SwarmLabelNamespace+".affinities"]
+	affinities := c.extractExprs("affinities")
-	var affinities []string
+	affinities = append(affinities, affinity)
-	json.Unmarshal([]byte(affnitiesJSON), &affinities)
-	affinities = append(affinities, "image==~"+image)
-
 	labels, err := json.Marshal(affinities)
 	if err != nil {
 		return err

cluster/config_test.go

@@ -82,10 +82,10 @@ func TestConsolidateResourceFields(t *testing.T) {
 
 }
 
-func TestAddSoftImageAffinity(t *testing.T) {
+func TestAddAffinity(t *testing.T) {
 	config := BuildContainerConfig(dockerclient.ContainerConfig{})
 	assert.Empty(t, config.Affinities())
 
-	config.AddSoftImageAffinity("testimage")
+	config.AddAffinity("image==~testimage")
 	assert.Len(t, config.Affinities(), 1)
 }

cluster/swarm/cluster.go

@@ -116,7 +116,7 @@ func (c *Cluster) createContainer(config *cluster.ContainerConfig, name string,
 
 	configTemp := config
 	if withSoftImageAffinity {
-		configTemp.AddSoftImageAffinity(config.Image)
+		configTemp.AddAffinity("image==~" + config.Image)
 	}
 
 	n, err := c.scheduler.SelectNodeForContainer(c.listNodes(), configTemp)