reflector

Reflector is a Kubernetes addon designed to monitor changes to resources (secrets and configmaps) and reflect changes to mirror resources in the same or other namespaces.

Share secrets across namespaces

Cluster can use reflector to copy secrets across namespaces. In particular, this can share the tls certificates from network to security.

• Cert-manager’s faq
• Emberstack Reflector

reflector will check secrets for an annotation indicating it may be replicated to other namespaces

apiVersion: v1
kind: Secret
metadata:
  name: <SECRET_NAME>
  namespace: <SECRET_NAMESPACE>
  annotations:
    reflector.v1.k8s.emberstack.com/reflection-allowed: 'true'
    reflector.v1.k8s.emberstack.com/reflection-allowed-namespaces: ns1,ns2,...   # "" (empty) == all namespaces
    # automatically create mirrored resources
    reflector.v1.k8s.emberstack.com/reflection-auto-enabled: 'true'
    reflector.v1.k8s.emberstack.com/reflection-auto-namespaces: ns1, ns2
    #

Source: kubernetes/apps/kube-system/reflector/README.md