constellation/.github/actions/e2e_autoscaling/action.yml

name: E2E autoscaling test
description: "Test autoscaling functionality of the operator."

inputs:
  kubeconfig:
    description: "The kubeconfig of the cluster to test."
    required: true

runs:
  using: "composite"
  steps:
    # This action assumes that the cluster is in an ready state, with all nodes joined and ready.

    - name: Determine number of workers in cluster
      id: worker_count
      shell: bash
      env:
        KUBECONFIG: ${{ inputs.kubeconfig }}
      run: |
        worker_count=$(kubectl get nodes -o json --selector='!node-role.kubernetes.io/control-plane' | jq '.items | length')
        echo "worker_count=${worker_count}" >> $GITHUB_OUTPUT
        echo "The cluster currently has ${worker_count} nodes."        

    # The following step identifies the name of the worker scaling group. As the scaling group is
    # a custom resource definition, we need to wait for its creation.

    - name: Find worker scaling group
      id: worker_name
      shell: bash
      env:
        KUBECONFIG: ${{ inputs.kubeconfig }}
      run: |
        TIMEOUT=1200
        WAIT=0
        until [[ $(( "$(kubectl get scalinggroups -o json | jq '.items | length')" )) -ge 2 ]] || [[ $WAIT -gt $TIMEOUT ]];
        do
            echo "Waiting for creation of custom resource definitions..."
            WAIT=$((WAIT+30))
            sleep 30
        done
        if [[ $WAIT -gt $TIMEOUT ]]; then
            echo "Timed out waiting for nodes to join"
            exit 1
        fi
        worker_group=$(kubectl get scalinggroups -o json | jq -r '.items[].metadata.name | select(contains("worker"))')
        echo "worker_name=${worker_group}" >> $GITHUB_OUTPUT
        echo "The name of your worker scaling group is '${worker_group}'."        

    - name: Patch autoscaling to true
      shell: bash
      env:
        KUBECONFIG: ${{ inputs.kubeconfig }}
      run: |
        worker_group=${{ steps.worker_name.outputs.worker_name }}
        kubectl patch scalinggroups ${worker_group} --patch '{"spec":{"autoscaling": true}}' --type='merge'
        kubectl get scalinggroup ${worker_group} -o jsonpath='{.spec}' | jq        

    - name: Set an autoscaling target/limit
      id: scaling_limit
      shell: bash
      env:
        KUBECONFIG: ${{ inputs.kubeconfig }}
      run: |
        worker_group=${{ steps.worker_name.outputs.worker_name }}
        worker_count=${{ steps.worker_count.outputs.worker_count }}
        worker_target=$((worker_count + 2))
        echo "worker_target=${worker_target}" >> $GITHUB_OUTPUT
        kubectl patch scalinggroups ${worker_group} --patch '{"spec":{"max": '${worker_target}'}}' --type='merge'
        kubectl get scalinggroup ${worker_group} -o jsonpath='{.spec}' | jq        

    # Number of replicas that are deployed to trigger autoscaling of nodes can't be determined exact.
    # The following steps calculates a value based on the limit of 110 pods per nodes, that is
    # described at https://kubernetes.io/docs/setup/best-practices/cluster-large/.
    # We try to fill the existing nodes and one additional node up to the limit,
    # and add half capacity for the second additional node so we have some space to the upper and
    # lower bound. If we deploy to many replicas, the deployment won't finish as we run into our
    # scaling limit. If we deploy not enough replicas, we won't see the desired number of nodes.

    - name: Deployment to trigger autoscaling
      shell: bash
      env:
        KUBECONFIG: ${{ inputs.kubeconfig }}
      run: |
        worker_count=${{ steps.worker_count.outputs.worker_count }}
        kubectl create -n default deployment nginx --image=nginx --replicas $(( 110 * (worker_count + 1) + 55 ))        

    - name: Wait for autoscaling and check result
      shell: bash
      env:
        KUBECONFIG: ${{ inputs.kubeconfig }}
      run: |
        kubectl wait deployment nginx --for condition=available --timeout=15m
        worker_count=$(kubectl get nodes -o json --selector='!node-role.kubernetes.io/control-plane' | jq '.items | length')
        if [[ $(( "${{ steps.scaling_limit.outputs.worker_target }}" )) -ne $(( "${worker_count}" )) ]]; then
          echo "::error::Expected worker count ${{ steps.scaling_limit.outputs.worker_target }}, but was ${worker_count}"
          exit 1
        fi        

    - name: Delete deployment
      if: always()
      shell: bash
      env:
        KUBECONFIG: ${{ inputs.kubeconfig }}
      run: kubectl delete deployment nginx