How to pull image from dockerhub in kubernetes?

Question

I am planning to deploy an application in my kubernetes-clustering infra. I pushed image to dockerhub repo. How can I pull image from dockerhub?

Answer 1

Kubernetes run docker pull pseudo/your-image:latest under the hood. image field in Kubernetes resources is simply the docker image to run.

spec:
  containers:
  - name: app
    image: pseudo/your-image:latest
[...]

As the docker image name contains no specific docker registry url, the default is docker.io. Your image is in fact docker.io/pseudo/your-image:latest

If your image is hosted in a private docker hub repo, you need to specify an image pull secret in the spec field.

spec:
  containers:
  - name: app
    image: pseudo/your-image:latest
  imagePullSecrets:
  - name: dockerhub-credential

Here is the documentation to create the secret containing your docker hub login: https://kubernetes.io/docs/tasks/configure-pod-container/pull-image-private-registry/

Answer 2

One line command to create a Docker registry secret

kubectl create secret docker-registry regcred --docker-username=<your-name> --docker-password=<your-pword> --docker-email=<your-email> -n <your-namespace>

Then you can use it in your deployment file under spec

spec:
  containers:
  - name: private-reg-container-name
    image: <your-private-image>
  imagePullSecrets:
  - name: regcred

More details: https://kubernetes.io/docs/tasks/configure-pod-container/pull-image-private-registry/#create-a-secret-in-the-cluster-that-holds-your-authorization-token