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 PostgreSQL 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.

Now, install KubeDB cli on your workstation and KubeDB operator in your cluster following the steps here.

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/postgres 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 Postgres, push the following images to your private registry.

  • kubedb/operator
  • kubedb/postgres
  • kubedb/postgres-tools

    $ export DOCKER_REGISTRY=<your-registry>
    
    $ docker pull kubedb/operator:0.8.0-rc.0 ; docker tag kubedb/operator:0.8.0-rc.0 $DOCKER_REGISTRY/operator:0.8.0-rc.0 ; docker push $DOCKER_REGISTRY/operator:0.8.0-rc.0
    $ docker pull kubedb/postgres:9.6 ; docker tag kubedb/postgres:9.6 $DOCKER_REGISTRY/postgres:9.6 ; docker push $DOCKER_REGISTRY/postgres:9.6
    $ docker pull kubedb/postgres-tools:9.6 ; docker tag kubedb/postgres-tools:9.6 $DOCKER_REGISTRY/postgres-tools:9.6 ; docker push $DOCKER_REGISTRY/postgres-tools:9.6
    

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 PostgreSQL database from Private Registry

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

Below is the Postgres object we will create in this tutorial

apiVersion: kubedb.com/v1alpha1
kind: Postgres
metadata:
  name: pvt-reg-postgres
  namespace: demo
spec:
  version: "9.6"
  storage:
    storageClassName: "standard"
    accessModes:
    - ReadWriteOnce
    resources:
      requests:
        storage: 50Mi
  imagePullSecrets:
    - name: myregistrykey

Now run the command to create this Postgres object:

$ kubedb create -f https://raw.githubusercontent.com/kubedb/cli/0.8.0-rc.0/docs/examples/postgres/private-registry/pvt-reg-postgres.yaml
postgres "pvt-reg-postgres" created

To check if the images pulled successfully from the repository, see if the PostgreSQL is in Running state:

$ kubectl get pods -n demo --selector="kubedb.com/name=pvt-reg-postgres" --watch
NAME                 READY     STATUS    RESTARTS   AGE
pvt-reg-postgres-0   1/1       Running   0          41s
^C⏎

Snapshot

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

Cleaning up

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

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

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

$ kubectl delete ns demo

If you would like to uninstall KubeDB operator, please follow the steps here.

Next Steps