udpate sample for create domain credentials

Author: markxnelson

kubernetes/samples/scripts/create-weblogic-domain-credentials/README.md

@@ -1,3 +1,49 @@
-# Ceating credentials for a WebLogic domain
+# Creating credentials for a WebLogic domain
 
-**TODO** write me 
+This sample demonstrates how to create a Kubernetes secret containing the 
+credentials for a WebLogic domain.  The operator expects this secret to be
+named following the pattern `domainUID-weblogic-credentials`, where `domainUID`
+is the unique identifier of the domain.  It must be in the same namespace 
+that the domain will run in.
+
+To use the sample, run the command:
+
+```
+$ ./create-weblogic-credentials.sh -u username -p password -d domainUID -n namespace -s secretName
+```
+
+The parameters are as follows:
+
+```  
+  -u username, must be specified.
+  -p password, must be specified.
+  -d domainUID, optional. The default value is domain1. If specified, the secret will be labeled with the domainUID unless the given value is an empty string.
+  -n namespace, optional. Use the default namespace if not specified
+  -s secretName, optional. If not specified, the secret name will be determined based on the domainUID value
+```
+
+This creates a `generic` secret containing the username and password as literal values.
+
+You can check the secret with the `kubectl get secret` command.  An example is shown below,
+including output:
+
+```
+$ kubectl -n domain-namespace-1 get secret domain1-weblogic-credentials -o yaml
+apiVersion: v1
+data:
+  password: d2VsY29tZTE=
+  username: d2VibG9naWM=
+kind: Secret
+metadata:
+  creationTimestamp: 2018-12-12T20:25:20Z
+  labels:
+    weblogic.domainName: domain1
+    weblogic.domainUID: domain1
+  name: domain1-weblogic-credentials
+  namespace: domain-namespace-1
+  resourceVersion: "5680"
+  selfLink: /api/v1/namespaces/domain-namespace-1/secrets/domain1-weblogic-credentials
+  uid: 0c2b3510-fe4c-11e8-994d-00001700101d
+type: Opaque
+
+```

kubernetes/samples/scripts/create-weblogic-domain-credentials/create-weblogic-credentials.sh

@@ -39,7 +39,7 @@ function validateKubectlAvailable {
 }
 
 function usage {
-  echo usage: ${script} -u username -p password [-d domainUID] [-n namespace] [-s sercretName] [-h]
+  echo usage: ${script} -u username -p password [-d domainUID] [-n namespace] [-s secretName] [-h]
   echo "  -u username, must be specified."
   echo "  -p password, must be specified."
   echo "  -d domainUID, optional. The default value is domain1. If specified, the secret will be labeled with the domainUID unless the given value is an empty string."