[Base64 (Encode & Decode)]
$ echo -n 'my-app' | base64
bXktYXBw
$ echo -n '39528$vdg7Jb' | base64
Mzk1MjgkdmRnN0pi

[Environment Variables]
$ kubectl create secret generic backend-user --from-literal=backend-username='backend-admin'
$ kubectl create secret generic db-user --from-literal=db-username='db-admin'
$ kubectl create secret generic test-secret --from-literal=username='my-app' --from-literal=password='39528$vdg7Jb'
