kubevela/docs/developers/set-autoscale.md

Automatically scale workload by cron or resource utilization

Prerequisites

• KEDA v2.0 Beta

  KEDA will be automatically deployed during vela installation, so just run the following command.

  $ vela install
  

Scale an application

• Deploy an application

  Run the following command to deploy application helloworld.

  $ vela svc deploy frontend -t webservice -a helloworld --image nginx:1.9.2 --port 80
  App helloworld deployed
  

  Check the replicas of Deployment frontend which is deployed by workload webservice helloworld and there is one replica.

  (TODO: The command below needs to be replaced with vela show to check the replicas.)

  $ kubectl get deploy frontend
  NAME       READY   UP-TO-DATE   AVAILABLE   AGE
  frontend   1/1     1            1           2m52s
  

• Scale the application by cron

  $ vela autoscale helloworld --svc frontend --minReplicas 1 --maxReplicas 4 --replicas 2 --name cron-test --startAt 21:00 --duration 2h --days "Monday, Tuesday"
  Adding autoscale for app frontend
  ⠋ Deploying ...
  ✅ Application Deployed Successfully!
    - Name: frontend
      Type: webservice
      HEALTHY Ready: 1/1
      Last Deployment:
        Created at: 2020-11-03 20:53:50 +0800 CST
        Updated at: 2020-11-03T21:01:20+08:00
      Traits:
        - autoscale: 
            maxReplicas=4
            minReplicas=1
            replicas=2
            startAt=21:00
            timezone=Asia/Shanghai
            days=Monday, Tuesday
            name=cron-test
            type=cron
            duration=2h
  

  The time is 21:07 which is in the active period of the trait which started at 21:00 and the duration is two hours. Check the replicas of Deployment frontend again, it has been scaled to 2.

  $ kubectl get deploy
  NAME       READY   UP-TO-DATE   AVAILABLE   AGE
  frontend   2/2     2            2           8m42s
  

  Wait after the period ends, the replicas will be one eventually.