fix issue 4874

Signed-off-by: Lyndon-Li <lyonghui@vmware.com>

pkg/nodeagent/node_agent.go

@@ -0,0 +1,69 @@
+/*
+Copyright The Velero Contributors.
+
+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 nodeagent
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/pkg/errors"
+	"k8s.io/client-go/kubernetes"
+
+	apierrors "k8s.io/apimachinery/pkg/api/errors"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	corev1client "k8s.io/client-go/kubernetes/typed/core/v1"
+)
+
+const (
+	// daemonSet is the name of the Velero restic daemonset.
+	daemonSet = "restic"
+)
+
+var (
+	DaemonsetNotFound = errors.New("daemonset not found")
+)
+
+// IsRunning checks if the node agent daemonset is running properly. If not, return the error found
+func IsRunning(ctx context.Context, kubeClient kubernetes.Interface, namespace string) error {
+	if _, err := kubeClient.AppsV1().DaemonSets(namespace).Get(ctx, daemonSet, metav1.GetOptions{}); apierrors.IsNotFound(err) {
+		return DaemonsetNotFound
+	} else if err != nil {
+		return err
+	} else {
+		return nil
+	}
+}
+
+// IsRunningInNode checks if the node agent daemonset pod is running properly in a specified node. If not, return the error found
+func IsRunningInNode(ctx context.Context, namespace string, nodeName string, podClient corev1client.PodsGetter) error {
+	if nodeName == "" {
+		return errors.New("node name is empty")
+	}
+
+	pods, err := podClient.Pods(namespace).List(ctx, metav1.ListOptions{LabelSelector: fmt.Sprintf("name=%s", daemonSet)})
+	if err != nil {
+		return errors.Wrap(err, "failed to list daemonset pods")
+	}
+
+	for _, pod := range pods.Items {
+		if pod.Spec.NodeName == nodeName {
+			return nil
+		}
+	}
+
+	return errors.Errorf("daemonset pod not found in node %s", nodeName)
+}