helm install fails with - and _ in values - kubernetes-helm

Question

helm install --name testapp ./testapp
Error: release testapp failed: ReplicationController "registry-creds-via-helm" is invalid: spec.template.spec.containers[0].env[0].valueFrom.secretKeyRef.name: Invalid value: "": a DNS-1123 subdomain must consist of lower case alphanumeric characters, '-' or '.', and must start and end with an alphanumeric character (e.g. 'example.com', regex used for validation is '[a-z0-9]([-a-z0-9]*[a-z0-9])?(\.[a-z0-9]([-a-z0-9]*[a-z0-9])?)*')
Can anyone point out what is the problem with my below yaml?
# cat testapp/templates/replicationController-ngn.yaml
apiVersion: v1
kind: ReplicationController
metadata:
name: registry-creds-via-helm
namespace: kube-system
labels:
version: v1.6
spec:
replicas: 1
selector:
name: registry-creds-via-helm
version: v1.9
template:
metadata:
labels:
name: registry-creds-via-helm
version: v1.9
spec:
containers:
- image: upmcenterprises/registry-creds:1.9
name: registry-creds
imagePullPolicy: Always
env:
- name: AWS_ACCESS_KEY_ID
valueFrom:
secretKeyRef:
key: AWS_ACCESS_KEY_ID
- name: AWS_SECRET_ACCESS_KEY
valueFrom:
secretKeyRef:
name: registry-creds
key: AWS_SECRET_ACCESS_KEY
- name: awsaccount
valueFrom:
secretKeyRef:
name: registry-creds
key: aws-account
- name: awsregion
valueFrom:
secretKeyRef:
name: registry-creds
key: aws-region
- name: aws-assume-role
valueFrom:
secretKeyRef:
name: registry-creds
key: aws_assume_role