UK8S - UCloud Global

Using UHub in UK8S

This article mainly explains how to create applications using UHub or your own private container image in UK8S.

Kubernetes supports specifying secrets for Pods to pull images from private repositories. Below we demonstrate how to use it to create an Nginx application by pulling an image from UHub;

1. Generate Secret Key

Use the following command to create a secret. Note to replace the uppercase values with your own information. MYSECRET is the key value of the secret which you can define by yourself;


# kubectl create secret docker-registry MYSECRET \
--docker-server=uhub.ucloud-global.com \
--docker-username=YOUR_UCLOUD_USERNAME@EMAIL.COM \
--docker-password=YOUR_UHUB_PASSWORD

2. Check the generated secret key information, we can see a secret named mysecret has been generated;


# kubectl get secret
NAME                  TYPE                                  DATA      AGE
default-token-sfv7s   kubernetes.io/service-account-token   3         8d
mysecret              kubernetes.io/dockerconfigjson        1         3h

3. Add Secret to the Pod Sample


apiVersion: v1
kind: Pod
metadata:
  name: nginx
  labels:
     app: nginx
spec:
  containers:
    - name: nginx
      image: uhub.ucloud-global.com/ucloud/nginx:1.9.2
  imagePullSecrets:
    - name: mysecret

4. Create an Nginx application with the above yaml file


# kubectl create -f pod.yml

5. Check the Pod status, notice the printed logs, we can see that Kubernetes successfully pulled the image from UHub instead of DockerHub.


# kubectl describe pods/nginx
.....
Events:
  Type    Reason     Age   From                  Message
  ----    ------     ----  ----                  -------
  Normal  Scheduled  1min    default-scheduler     Successfully assigned default/nginx to 10.25.95.46
  Normal  Pulling    1min    kubelet, 10.25.95.46  pulling image "uhub.ucloud-global.com/ucloud/nginx:1.9.2"
  Normal  Pulled     1min    kubelet, 10.25.95.46  Successfully pulled image "uhub.ucloud-global.com/ucloud/nginx:1.9.2"
  Normal  Created    1min    kubelet, 10.25.95.46  Created container
  Normal  Started    1min    kubelet, 10.25.95.46  Started container