Using the Registry Aliases Addon - Minikube

Registry Aliases Addon

An addon to minikube that can help push and pull from the minikube registry using custom domain names. The custom domain names will be made resolveable from with in cluster and at minikube node.

How to use ?

Start minikube

shell

minikube start -p demo

This addon depends on registry addon, it need to be enabled before the alias addon is installed:

Enable internal registry

shell

minikube addons enable registry

Verifying the registry deployment

shell

watch kubectl get pods -n kube-system

shell

NAME                           READY   STATUS    RESTARTS   AGE
coredns-6955765f44-kpbzt       1/1     Running   0          16m
coredns-6955765f44-lzlsv       1/1     Running   0          16m
etcd-demo                      1/1     Running   0          16m
kube-apiserver-demo            1/1     Running   0          16m
kube-controller-manager-demo   1/1     Running   0          16m
kube-proxy-q8rb9               1/1     Running   0          16m
kube-scheduler-demo            1/1     Running   0          16m
*registry-4k8zs*              1/1     Running   0          40s
registry-proxy-vs8jt           1/1     Running   0          40s
storage-provisioner            1/1     Running   0          16m

shell

kubectl get svc -n kube-system

shell

NAME       TYPE        CLUSTER-IP     EXTERNAL-IP   PORT(S)                  AGE
kube-dns   ClusterIP   10.96.0.10     <none>        53/UDP,53/TCP,9153/TCP   17m
registry   ClusterIP   10.97.247.75   <none>        80/TCP                   94s

NOTE: Please make a note of the CLUSTER-IP of registry service

Enable registry aliases addon

shell

minikube addons enable registry-aliases
🌟  The 'registry-aliases' addon is enabled

You can check the mikikube vm's /etc/hosts file for the registry aliases entries:

shell

watch minikube ssh -- cat /etc/hosts

shell

127.0.0.1       localhost
127.0.1.1 demo
10.97.247.75    example.org
10.97.247.75    example.com
10.97.247.75    test.com
10.97.247.75    test.org

The above output shows that the Daemonset has added the registryAliases from the ConfigMap pointing to the internal registry's CLUSTER-IP.

Update CoreDNS

The coreDNS would have been automatically updated by the patch-coredns. A successful job run will have coredns ConfigMap updated like:

yaml

apiVersion: v1
data:
  Corefile: |-
    .:53 {
        errors
        health
        rewrite name example.com registry.kube-system.svc.cluster.local
        rewrite name example.org registry.kube-system.svc.cluster.local
        rewrite name test.com registry.kube-system.svc.cluster.local
        rewrite name test.org registry.kube-system.svc.cluster.local
        kubernetes cluster.local in-addr.arpa ip6.arpa {
           pods insecure
           upstream
           fallthrough in-addr.arpa ip6.arpa
        }
        prometheus :9153
        proxy . /etc/resolv.conf
        cache 30
        loop
        reload
        loadbalance
    }
kind: ConfigMap
metadata:
  name: coredns

To verify it run the following command:

shell

kubectl get cm -n kube-system coredns -o yaml

Once you have successfully patched you can now push and pull from the registry using suffix example.com, example.org,test.com and test.org.

The successful run will show the following extra pods (Daemonset, Job) in kube-system namespace:

shell

NAME                                    READY   STATUS      RESTARTS   AGE
registry-aliases-hosts-update-995vx     1/1     Running     0          47s
registry-aliases-patch-core-dns-zsxfc   0/1     Completed   0          47s

Verify with sample application

You can verify the deployment end to end using the example application.

shell

git clone https://github.com/kameshsampath/minikube-registry-aliases-demo
cd minikube-registry-aliases-demo

Make sure you set the docker context using eval $(minikube -p demo docker-env)

Deploy the application using Skaffold:

shell

skaffold dev --port-forward

Once the application is running try doing curl localhost:8080 to see the Hello World response

You can also update skaffold.yaml and app.yaml, to use test.org, test.com or example.org as container registry urls, and see all the container image names resolves to internal registry, resulting in successful build and deployment.

NOTE:

You can also update skaffold.yaml and app. yaml, to use test.org, test.com or > example.org as container registry urls, and see all the > container image names resolves to internal registry, resulting in successful build and deployment.