chore(EnvVar Configuration): Updated documentation.

Author: rhuss

README.adoc

@@ -63,7 +63,7 @@ link:structural/Ambassador/README.adoc[Ambassador]::
 === Configuration Patterns
 
 link:configuration/EnvVarConfiguration/README.adoc[EnvVar Configuration]::
-  A simple example of how to use environment variables literally and from ConfigMaps and Secrets for our random-generator service. [*]
+  A simple example of how to use environment variables literally and from ConfigMaps and Secrets for our random-generator service.
 link:configuration/ConfigurationResource/README.adoc[Configuration Resource]::
   Example how to configure the random-generator Spring Boot application with a ConfigMap [*]
 link:configuration/ImmutableConfiguration/README.adoc[Immutable Configuration]::

configuration/EnvVarConfiguration/README.adoc

@@ -1,36 +1,47 @@
 == Envvar Configuration
 
-IMPORTANT: The instructions have not been written/finished, but the resource file has been verified. Instructions will be added soon.
+This example assumes that you have a Kubernetes cluster to your avail.
+Please check link:../../INSTALL.adoc#minikube[INSTALL] for various installation options.
+
+First, lets create a ConfigMap and a Secert with one entry, respecively:
 
 [source, bash]
 ----
 kubectl create configmap random-generator-config --from-literal=pattern=EnvVarConfiguration
 
 kubectl create secret generic random-generator-secret --from-literal=seed=11232156346
+----
 
+We use both resource for defining environment variable in a simple Pod declaration for our sample https://github.com/k8spatterns/random-generator[random-generator REST service]:
 
-kubectl create -f pod.yml
+[source, bash]
+----
+kubectl create -f https://k8spatterns.io/EnvVarConfiguration/pod.yml
+----
 
-kubectl create -f service.yml
+If you look into this resource description, you see how our ConfigMap and Secret is used to set two environment variables `PATTERN` and `SEED` which are then also exposed via the random-generator rest service.
 
+In order to access this rest service let's expose the Pod via
 
+[source, bash]
+----
+kubectl create -f https://k8spatterns.io/EnvVarConfiguration/service.yml
+----
+
+For simplicity reasons, this service exposed the service port via a `nodePort`.
+Assuming, that your are using Minikube you can now access this service from your dekstop with:
+
+[source, bash]
+----
 port=$(kubectl get svc random-generator -o jsonpath={.spec.ports[0].nodePort})
 curl -s http://$(minikube ip):$port/info | jq .
-
-{
-  "memory.free": 24,
-  "seed": 11232156346,
-  "memory.used": 46,
-  "cpu.procs": 1,
-  "memory.max": 481,
-  "logFile": "/tmp/random.log",
-  "pattern": "EnvVarConfiguration",
-  "id": "b5942022-5925-4672-9c26-8cf255b5ccf0",
-  "version": "1.0"
-}
 ----
 
+If you are not using Minikube, just insert the external facing IP address of one of your cluster's node for the host address.
 
+* Do you se, how the environment variables are exposed ?
+* What happens when you change the data of the ConfigMap or Secret (e.g. with `kubectl edit cm random-generator-config`) ? Is this changed value reflected in the response of your curl request /
+* What would you have to do, to get this value returned in the HTTP response ?
 
 === More Information