helm - Create keystone public service failed with nil external vip

helm - Install "keystone-public-svc" failed with nil external vip

When user try to install keystone-public-svc with default value.
Helm will installed failed with following messages

$ helm install microservice/keystone-public-svc
Created tunnel using local port: '41270'
SERVER: "localhost:41270"
CHART PATH: /home/lyan/helm/microservice/keystone-public-svc
Error: error validating "": error validating data: unexpected nil value for field spec.externalIPs[0]

Keystone-public-svc will default enable external port, this will cause svc yaml will
need to get externa_vip value. But it will not been assign any value.
Therefore the svc yaml will output:

externalIPs:
    -

Maybe we should check whether external port had been enable and external vip had been added,
then assign external vip.