Add metadata flags

[paulbarfuss]

Apologies for the delay in re-opening this pull request. This would add only the following functionality to rbac-tool gen and rbac-tool show commands. While the intent of rbac-tool show is not necessarily to generate clusterroles/roles, it made sense to include the flags both places since they call the same generateRole function.

This will also maintain the same default role names and namespace for users that are not passing the new flags.

Generate Role:

rbac-tool gen \
  --allowed-groups ,apps \
  --generated-type Role \
  --name foo \
  --namespace bar \
  --annotations argocd.argoproj.io/sync-wave=2,rbac.authorization.kubernetes.io/autoupdate=true

Output:

apiVersion: rbac.authorization.k8s.io/v1
kind: Role
metadata:
  annotations:
    argocd.argoproj.io/sync-wave: "2"
    rbac.authorization.kubernetes.io/autoupdate: "true"
  creationTimestamp: null
  name: foo
  namespace: bar
rules:
...

Generate ClusterRole:

rbac-tool gen \
  --allowed-groups ,apps \
  --name foo \     
  --annotations argocd.argoproj.io/sync-wave=2,rbac.authorization.kubernetes.io/autoupdate=true

Output:

apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
  annotations:
    argocd.argoproj.io/sync-wave: "2"
    rbac.authorization.kubernetes.io/autoupdate: "true"
  creationTimestamp: null
  name: foo

Thanks again! 😄

[gadinaor-r7]

Looks mostly fine.

the default "custom-cluster-role" should be "custom-role" for compatibility with previous versions

[gadinaor-r7]

see #105