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 Elasticsearch 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.

To keep things isolated, this tutorial uses a separate namespace called demo throughout this tutorial.

$ kubectl create ns demo
namespace "demo" created

$ kubectl get ns demo
NAME    STATUS  AGE
demo    Active  5s

Note: Yaml files used in this tutorial are stored in docs/examples/elasticsearch folder in github repository kubedb/cli.

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 Elasticsearch, push the following images to your private registry.

  • kubedb/operator
  • kubedb/elasticsearch
  • kubedb/elasticsearch-tools

    $ export DOCKER_REGISTRY=<your-registry>
    
    $ docker pull kubedb/operator:0.8.0-beta.2 ; docker tag kubedb/operator:0.8.0-beta.2 $DOCKER_REGISTRY/operator:0.8.0-beta.2 ; docker push $DOCKER_REGISTRY/operator:0.8.0-beta.2
    $ docker pull kubedb/elasticsearch:5.6 ; docker tag kubedb/elasticsearch:5.6 $DOCKER_REGISTRY/elasticsearch:5.6 ; docker push $DOCKER_REGISTRY/elasticsearch:5.6
    $ docker pull kubedb/elasticsearch-tools:5.6 ; docker tag kubedb/elasticsearch-tools:5.6 $DOCKER_REGISTRY/elasticsearch-tools:5.6 ; docker push $DOCKER_REGISTRY/elasticsearch-tools:5.6
    

Create ImagePullSecret

ImagePullSecrets is a type of a Kubernetes 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.

Note; 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.

Deploy Elasticsearch database from Private Registry

While deploying Elasticsearch from private repository, you have to add myregistrykey secret in Elasticsearch spec.imagePullSecrets.

Below is the Elasticsearch CRD object we will create in this tutorial.

apiVersion: kubedb.com/v1alpha1
kind: Elasticsearch
metadata:
  name: pvt-reg-elasticsearch
  namespace: demo
spec:
  version: 5.6
  storage:
    storageClassName: "standard"
    accessModes:
    - ReadWriteOnce
    resources:
      requests:
        storage: 50Mi
  imagePullSecrets:
    - name: myregistrykey

Now run the command to deploy this Elasticsearch object:

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

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

$ kubedb get es -n demo pvt-reg-elasticsearch -o wide
NAME                    VERSION   STATUS    AGE
pvt-reg-elasticsearch   5.6       Running   33m

Snapshot

We don’t need to add imagePullSecret for Snapshot objects. Just create Snapshot object and KubeDB operator will reuse the ImagePullSecret from Elasticsearch object.

Cleaning up

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

$ kubedb delete es,drmn,snap -n demo --all --force
$ kubectl delete ns demo

Next Steps