add longhorn demo

active/kubernetes_longhorn/demo-app.yaml

@@ -0,0 +1,31 @@
+apiVersion: v1
+kind: PersistentVolumeClaim
+metadata:
+  name: storage-test-pvc
+spec:
+  accessModes:
+    - ReadWriteOnce
+  resources:
+    requests:
+      storage: 1Gi
+  # If you want to test a specific storage class, uncomment the line below:
+  # storageClassName: <your-storage-class-name>
+---
+apiVersion: v1
+kind: Pod
+metadata:
+  name: storage-test-pod
+spec:
+  containers:
+    - name: busybox
+      image: busybox
+      command:
+        ["sh", "-c", "while true; do date >> /mnt/test.txt; sleep 10; done"]
+      volumeMounts:
+        - name: test-volume
+          mountPath: /mnt
+  restartPolicy: Always
+  volumes:
+    - name: test-volume
+      persistentVolumeClaim:
+        claimName: storage-test-pvc