5.6.2. Enabling node auto-scaling for the hosted cluster

Procedure

1. To enable auto-scaling, enter the following command:

   $ oc -n <hosted_cluster_namespace> patch nodepool <hosted_cluster_name> \
     --type=json \
     -p '[{"op": "remove", "path": "/spec/replicas"},{"op":"add", "path": "/spec/autoScaling", "value": { "max": 5, "min": 2 }}]'

2. Create a workload that requires a new node.

   1. Create a YAML file that contains the workload configuration, by using the following example:

      apiVersion: apps/v1
      kind: Deployment
      metadata:
        labels:
          app: reversewords
        name: reversewords
        namespace: default
      spec:
        replicas: 40
        selector:
          matchLabels:
            app: reversewords
        template:
          metadata:
            labels:
              app: reversewords
          spec:
            containers:
            - image: quay.io/mavazque/reversewords:latest
              name: reversewords
              resources:
                requests:
                  memory: 2Gi

   2. Save the file with the name workload-config.yaml.

   3. Apply the YAML by entering the following command:

      $ oc apply -f workload-config.yaml

3. Extract the admin-kubeconfig secret by entering the following command:

   $ oc extract -n <hosted_cluster_namespace> \
     secret/<hosted_cluster_name>-admin-kubeconfig \
     --to=./hostedcluster-secrets --confirm

   Example output

   hostedcluster-secrets/kubeconfig

4. You can check if new nodes are in the Ready status by entering the following command:

   $ oc --kubeconfig ./hostedcluster-secrets get nodes

5. To remove the node, delete the workload by entering the following command:

   $ oc --kubeconfig ./hostedcluster-secrets -n <namespace> \
     delete deployment <deployment_name>

6. Wait for several minutes to pass without requiring the additional capacity. You can confirm that the node was removed by entering the following command:

   $ oc --kubeconfig ./hostedcluster-secrets get nodes