fix create command not support namespace in yaml file (#962)

Signed-off-by: zhaozhiqiang <zhaozhiqiang@lixiang.com>

pkg/kubectl-argo-rollouts/cmd/create/create.go

@@ -137,6 +137,20 @@ func unmarshal(fileBytes []byte, obj interface{}) error {
 	}
 }
 
+func (c *CreateOptions) getNamespace(un unstructured.Unstructured) string {
+	ns := c.ArgoRolloutsOptions.Namespace()
+	if md, ok := un.Object["metadata"]; ok {
+		if md == nil {
+			return ns
+		}
+		metadata := md.(map[string]interface{})
+		if internalns, ok := metadata["namespace"]; ok {
+			ns = internalns.(string)
+		}
+	}
+	return ns
+}
+
 func (c *CreateOptions) createResource(path string) (runtime.Object, error) {
 	ctx := context.TODO()
 	fileBytes, err := ioutil.ReadFile(path)
@@ -149,7 +163,7 @@ func (c *CreateOptions) createResource(path string) (runtime.Object, error) {
 		return nil, err
 	}
 	gvk := un.GroupVersionKind()
-	ns := c.ArgoRolloutsOptions.Namespace()
+	ns := c.getNamespace(un)
 	switch {
 	case gvk.Group == rollouts.Group && gvk.Kind == rollouts.ExperimentKind:
 		var exp v1alpha1.Experiment