Enable TLS for Kube-Registry

This document describes how to enable TLS for kube-registry. Before you start, please check if you have all the prerequisite:

A domain for kube-registry. Assuming it is myregistrydomain.com.
Domain certificate and key. Assuming they are domain.crt and domain.key

Pack domain.crt and domain.key into a Secret

$ kubectl --namespace=kube-system create secret generic registry-tls-secret --from-file=domain.crt=domain.crt --from-file=domain.key=domain.key

Run Registry

Please be noted that this sample rc is using emptyDir as storage backend for simplicity.

apiVersion: v1
kind: ReplicationController
metadata:
  name: kube-registry-v0
  namespace: kube-system
  labels:
    k8s-app: kube-registry
    version: v0
#    kubernetes.io/cluster-service: "true"
spec:
  replicas: 1
  selector:
    k8s-app: kube-registry
    version: v0
  template:
    metadata:
      labels:
        k8s-app: kube-registry
        version: v0
#        kubernetes.io/cluster-service: "true"
    spec:
      containers:
      - name: registry
        image: registry:2
        resources:
          # keep request = limit to keep this container in guaranteed class
          limits:
            cpu: 100m
            memory: 100Mi
          requests:
            cpu: 100m
            memory: 100Mi
        env:
        - name: REGISTRY_HTTP_ADDR
          value: :5000
        - name: REGISTRY_STORAGE_FILESYSTEM_ROOTDIRECTORY
          value: /var/lib/registry
        - name: REGISTRY_HTTP_TLS_CERTIFICATE
          value: /certs/domain.crt
        - name: REGISTRY_HTTP_TLS_KEY
          value: /certs/domain.key
        volumeMounts:
        - name: image-store
          mountPath: /var/lib/registry
        - name: cert-dir
          mountPath: /certs
        ports:
        - containerPort: 5000
          name: registry
          protocol: TCP
      volumes:
      - name: image-store
        emptyDir: {}
      - name: cert-dir
        secret:
          secretName: registry-tls-secret

Expose External IP for Kube-Registry

Modify the default kube-registry service to LoadBalancer type and point the DNS record of myregistrydomain.com to the service external ip.

apiVersion: v1
kind: Service
metadata:
  name: kube-registry
  namespace: kube-system
  labels:
    k8s-app: kube-registry
#    kubernetes.io/cluster-service: "true"
    kubernetes.io/name: "KubeRegistry"
spec:
  selector:
    k8s-app: kube-registry
  type: LoadBalancer
  ports:
  - name: registry
    port: 5000
    protocol: TCP

To Verify

Now you should be able to access your kube-registry from another docker host.

docker pull busybox
docker tag busybox myregistrydomain.com:5000/busybox
docker push myregistrydomain.com:5000/busybox
docker pull myregistrydomain.com:5000/busybox