How to: copy the working env-var within the container spec to webenv.yml to avoid adding unnecessary fields
kubectl apply -f webenv.yml
kubectl get deploy,po # deployment web-env shows 1/1 READY, copy pod name
kubectl exec -it $POD_NAME -- printenv # shows MYSQL_ROOT_PASSWORD,MYSQL_ALLOW_EMPTY_PASSWORD
kubectl run mypod --image=mysql --dry-run=client -oyaml > pod.yml
kubectl apply -f pod.yml # need existing pod to generate yaml for env-vars
kubectl set env pod mypod --keys=MYSQL_ROOT_PASSWORD,MYSQL_ALLOW_EMPTY_PASSWORD --from=configmap/mycm-env --dry-run=client -oyaml|less