New to KubeDB? Please start here.

Using private Docker registry

KubeDB operator supports using private Docker registry. This tutorial will show you how to use KubeDB to run Memcached database using private Docker images.

Before You Begin

At first, you need to have a Kubernetes cluster, and the kubectl command-line tool must be configured to communicate with your cluster. If you do not already have a cluster, you can create one by using Minikube.

You will also need a docker private registry or private repository. In this tutorial we will use private repository of docker hub.

You have to push the required images from KubeDB’s Docker hub account into your private registry. For memcached, push the following images to your private registry.

• kubedb/operator
• kubedb/memcached

$ export DOCKER_REGISTRY=<your-registry>

$ docker pull kubedb/operator:0.8.0 ; docker tag kubedb/operator:0.8.0 $DOCKER_REGISTRY/operator:0.8.0 ; docker push $DOCKER_REGISTRY/operator:0.8.0
$ docker pull kubedb/memcached:1.5.4 ; docker tag kubedb/memcached:1.5.4 $DOCKER_REGISTRY/memcached:1.5.4 ; docker push $DOCKER_REGISTRY/memcached:1.5.4

Create ImagePullSecret

ImagePullSecrets is a type of a Kubernete Secret whose sole purpose is to pull private images from a Docker registry. It allows you to specify the url of the docker registry, credentials for logging in and the image name of your private docker image.

Run the following command, substituting the appropriate uppercase values to create an image pull secret for your private Docker registry:

$ kubectl create secret docker-registry myregistrykey \
  --docker-server=DOCKER_REGISTRY_SERVER \
  --docker-username=DOCKER_USER \
  --docker-email=DOCKER_EMAIL \
  --docker-password=DOCKER_PASSWORD

secret "myregistrykey" created.

If you wish to follow other ways to pull private images see official docs of kubernetes.

NB: If you are using kubectl 1.9.0, update to 1.9.1 or later to avoid this issue.

Install KubeDB operator

When installing KubeDB operator, set the flags --docker-registry and --image-pull-secret to appropriate value. Follow the steps to install KubeDB operator properly in cluster so that to points to the DOCKER_REGISTRY you wish to pull images from.

Create Demo namespace

To keep things isolated, this tutorial uses a separate namespace called demo throughout this tutorial. Run the following command to prepare your cluster for this tutorial:

$ kubectl create ns demo
namespace "demo" created

$ kubectl get ns
NAME          STATUS    AGE
default       Active    45m
demo          Active    10s
kube-public   Active    45m
kube-system   Active    45m

Deploy Memcached database from Private Registry

While deploying Memcached from private repository, you have to add myregistrykey secret in Memcached spec.imagePullSecrets. Below is the Memcached CRD object we will create.

apiVersion: kubedb.com/v1alpha1
kind: Memcached
metadata:
  name: memcd-pvt-reg
  namespace: demo
spec:
  replicas: 3
  version: "1.5.4"
  doNotPause: true
  resources:
    requests:
      memory: 64Mi
      cpu: 250m
    limits:
      memory: 128Mi
      cpu: 500m
  imagePullSecrets:
    - name: myregistrykey

Now run the command to deploy this Memcached object:

$ kubedb create -f https://raw.githubusercontent.com/kubedb/cli/0.8.0/docs/examples/memcached/private-registry/demo-2.yaml
memcached "memcached-pvt-reg" created

To check if the images pulled successfully from the repository, see if the Memcached is in running state:

$ kubectl get pods -n demo -w
NAME                             READY     STATUS              RESTARTS   AGE
memcd-pvt-reg-7fd79d6c76-7xswr   0/1       ContainerCreating   0          10s
memcd-pvt-reg-7fd79d6c76-f42g5   0/1       ContainerCreating   0          10s
memcd-pvt-reg-7fd79d6c76-t7b9w   0/1       ContainerCreating   0          10s
memcd-pvt-reg-7fd79d6c76-f42g5   1/1       Running             0          46s
memcd-pvt-reg-7fd79d6c76-7xswr   1/1       Running             0          50s
memcd-pvt-reg-7fd79d6c76-t7b9w   1/1       Running             0          54s

$ kubedb get mc -n demo
NAME            STATUS    AGE
memcd-pvt-reg   Running   2m

Cleaning up

To cleanup the Kubernetes resources created by this tutorial, run:

$ kubectl patch -n demo mc/memcd-pvt-reg -p '{"spec":{"doNotPause":false}}' --type="merge"
$ kubectl delete -n demo mc/memcd-pvt-reg

$ kubectl patch -n demo drmn/memcd-pvt-reg -p '{"spec":{"wipeOut":true}}' --type="merge"
$ kubectl delete -n demo drmn/memcd-pvt-reg

$ kubectl delete ns demo
namespace "demo" deleted

Next Steps

• Monitor your Memcached database with KubeDB using out-of-the-box CoreOS Prometheus Operator.
• Monitor your Memcached database with KubeDB using out-of-the-box builtin-Prometheus.
• Detail concepts of Memcached object.
• Wondering what features are coming next? Please visit here.
• Want to hack on KubeDB? Check our contribution guidelines.