add docker desktop (#301)

contents/local-cluster/docker-desktop/README.md

@@ -0,0 +1,67 @@
+# Docker Desktop
+
+Load Balancer in Kubernetes in Docker Desktop (ref: https://www.docker.com/blog/how-kubernetes-works-under-the-hood-with-docker-desktop/)
+
+```
+ubectl apply -f - <<EOF
+apiVersion: v1
+kind: Service
+metadata:
+  name: tutorial
+spec:
+  ports:
+  - name: 80-tcp
+    port: 80
+    protocol: TCP
+    targetPort: 80
+  selector:
+    com.docker.project: tutorial
+  type: LoadBalancer
+status:
+  loadBalancer: {}
+
+---
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  labels:
+    com.docker.project: tutorial
+  name: tutorial
+spec:
+  replicas: 1
+  selector:
+    matchLabels:
+      com.docker.project: tutorial
+  strategy:
+    type: Recreate
+  template:
+    metadata:
+      labels:
+        com.docker.project: tutorial
+    spec:
+      containers:
+      - image: docker/getting-started
+        name: tutorial
+        ports:
+        - containerPort: 80
+          protocol: TCP
+        resources: {}
+      restartPolicy: Always
+status: {}
+EOF
+```
+
+```
+kubectl get svc tutorial
+NAME       TYPE           CLUSTER-IP       EXTERNAL-IP   PORT(S)        AGE
+tutorial   LoadBalancer   10.105.129.171   localhost     80:32088/TCP   2m
+```
+
+http://localhost/tutorial/
+
+![](docker-tutorial.png)
+
+```
+kubectl delete svc tutorial
+kubectl delete deploy tutorial
+```