Update hello-world.md

Author: vorburger

docs/hello-world.md

@@ -1,13 +1,48 @@
 # hello, world
 
+Whatever [Kubernetes Installation](install.md) you use, here is a first example how to use it,
+inspired by [Kubernetes' tutorial](https://kubernetes.io/docs/tutorials/stateless-application/expose-external-ip-address/)
+or [GKE's Quickstart](https://cloud.google.com/kubernetes-engine/docs/quickstart).
+
 ## [echoserver](https://github.com/kubernetes/kubernetes/tree/master/test/images/echoserver)
 
-    k create deployment echoserver --image=k8s.gcr.io/echoserver:1.10
-    k expose deployment echoserver --type=LoadBalancer --port=8080
-    curl $(minikube service --url=true echoserver)
+    $ k create deployment echoserver --image=k8s.gcr.io/echoserver:1.10
+    $ k expose deployment echoserver --type=LoadBalancer --port=8080
+    $ k get service echoserver
+    NAME         TYPE           CLUSTER-IP   EXTERNAL-IP     PORT(S)          AGE
+    echoserver   LoadBalancer   10.x.y.z     a.b.c.d         8080:32151/TCP   1m
+
+The `echoserver` web page is now available at http://a.b.c.d:8080.
+If the external IP address is still shown as _"pending",_ then wait for a minute and retry.
+BTW when using [`minikube`](install.md#minikube) there may not be an `EXTERNAL-IP`, then you have to use `minikube service` instead:
+
+    $ minikube service --url=true echoserver
+
+Execute the following commands to have a look at what Kubernetes created based on the commands above:
+
+    $ k describe service echoserver
+    $ k get -o yaml service echoserver
+    $ k describe deployment echoserver
+    $ k get -o yaml deployment echoserver
+    $ k describe replicaset echoserver
+    $ k get -o yaml replicaset
+    $ k get -o yaml pod
+    $ k describe pod echoserver
+    (...)
+    Limits:
+      cpu:                500m
+      ephemeral-storage:  1Gi
+      memory:             2Gi
+
+Note how the CPU, Memory and Storage Limits were automatically chosen. In a next step, you'll want to set more appropriate limits yourself.
+To remove this first example from your cluster, clean up both the service and deployment, which will also remove its replicaset and pod:
+    
+    $ k delete service echoserver
+    $ k delete deployment echoserver
 
-## Dashboard
+## Dashboard for Minikube
 
     minikube dashboard
 
-If you run `minikube` inside a Virtual Machine (VM) instead of on your Laptop/Desktop workstation, then you'll need to set up some port forwarding to be able to access services in your local web browser.
+If you run `minikube` inside a Virtual Machine (VM) instead of on your Laptop/Desktop workstation,
+then you'll need to set up some port forwarding to be able to access services in your local web browser.