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Kubernetes Blue-green Deployment in Kubesphere

The blue-green release provides a zero downtime deployment, which means the new version can be deployed with the old one preserved. At any time, only one of the versions is active serving all the traffic, while the other one remains idle. If there is a problem with running, you can quickly roll back to the old version.

blue-green-0

Prerequisites

Create a Blue-green Deployment Job

  1. Log in to KubeSphere as project-regular and go to Grayscale Release. Under Categories, click Create Job on the right of Blue-green Deployment.

  2. Set a name for it and click Next.

  3. On the Grayscale Release Components tab, select your app from the drop-down list and the Service for which you want to implement the blue-green deployment. If you also use the sample app Bookinfo, select reviews and click Next.

  4. On the Grayscale Release Version tab, add another version (e.g v2) as shown in the following figure and click Next:

    blue-green-4

    Note

    The image version is v2 in the screenshot.
  5. On the Policy Config tab, to allow the app version v2 to take over all the traffic, select Take over all traffic and click Create.

  6. The blue-green deployment job created is displayed under the tab Job Status. Click it to view details.

    blue-green-job-list

  7. Wait for a while and you can see all the traffic go to the version v2:

    blue-green-6

  8. The new Deployment is created as well.

    version2-deployment

  9. You can get the virtual service to identify the weight by running the following command:

    kubectl -n demo-project get virtualservice -o yaml
    

    Note

    • When you run the command above, replace demo-project with your own project (namely, namespace) name.
    • If you want to run the command from the web kubectl on the KubeSphere console, you need to use the account admin.
  10. Expected output:

    ...
      spec:
        hosts:
        - reviews
        http:
        - route:
          - destination:
              host: reviews
              port:
                number: 9080
              subset: v2
            weight: 100
            ...
    

Take a Job Offline

After you implement the blue-green deployment, and the result meets your expectation, you can take the task offline with the version v1 removed by clicking Job offline.

blue-green-7


Thanks for the feedback. If you have a specific question about how to use KubeSphere, ask it on Slack. Open an issue in the GitHub repo if you want to report a problem or suggest an improvement.