tf-batch.yml

name: Terraform Batch

on:
  # Permit targeted manual trigger within console
  workflow_dispatch:
    inputs:
      pod-selection-regex:
        description: Regex to match pods to deploy, e.g. "dev-s00[1-5]" or substring match like "s001", use asterisk "*" to select all Pods
        type: string
        required: true
        default: '*'
      concurrency:
        description: Deploy strategy, concurrent or sequential
        type: choice
        required: true
        default: concurrent
        options:
          - concurrent
          - sequential

jobs:
  
  gather-info:
    name: Gather information
    runs-on: ubuntu-latest
    
    # Set outputs for orchestration job
    outputs:
      MAX_PARALLEL: ${{ steps.set-deploy-strategy.outputs.MAX_PARALLEL }}
      TARGETED_PODS: ${{ steps.set-targeted-pods.outputs.TARGETED_PODS }}

    steps:
    - uses: actions/checkout@v3
    
    - name: Set Concurrency to ${{ github.event.inputs.concurrency == 'concurrent' && 100 || 1 }}
      id: set-deploy-strategy
      run: |
        # If strategy is concurrent, max parallel is set to 100 (arbitrarily high number)
        if [[ ${{ github.event.inputs.concurrency }} == "concurrent" ]]; then
          echo "Concurrent deployment strategy selected, max parallel set to 100"
          echo "MAX_PARALLEL=100" >> $GITHUB_OUTPUT

        # If strategy is sequential, max parallel is set to 1
        elif [[ ${{ github.event.inputs.concurrency }} == "sequential" ]]; then
          echo "Concurrent deployment strategy selected, max parallel set to 100"
          echo "MAX_PARALLEL=1" >> $GITHUB_OUTPUT
        fi

    - name: Specify pods to deploy using regex ${{ github.event.inputs.pod-selection-regex }}
      id: set-targeted-pods
      run: |

        # Read TF apply workfile as var
        WORKFILE=$(cat ./.github/workflows/tf-deploy.yml)
        
        # Get all targateable pods from workflow file
        ALL_PODS=$(echo "$WORKFILE" | yq .on.workflow_dispatch.inputs.location.options | cut -d " " -f 2)
        
        # If pod-selection-regex set to wildcard, select all pods
        if [[ ${{ github.event.inputs.pod-selection-regex }} == "*" ]]; then
          echo "Wildcard used to select all pods, selecting all pods"
          TARGETED_PODS=$ALL_PODS
        else
          echo "Wildcard not used to select all pods, selecting pods using regex"
          TARGETED_PODS=$(echo "$ALL_PODS" | grep -E "${{ github.event.inputs.pod-selection-regex }}" )
        fi

        # Print out list of pods we'll be targeting
        echo "We'll be targeting the following pods:"
        while IFS=$'\n' read -r POD; do
          echo "- $POD"
        done <<< "$TARGETED_PODS"

        # Remove old file and put all pods into list like: 'pod1','pod2','pod3'
        rm -f TARGETED_PODS_HOLDER
        while IFS=$'\n' read -r POD; do
          printf "'$POD'", >> TARGETED_PODS_HOLDER
        done <<< "$TARGETED_PODS"

        # Read file as var and remove trailing comma
        TARGETED_PODS_OUTPUT=$(cat TARGETED_PODS_HOLDER | sed 's/,$//')

        # Send TARGETED_PODS to output
        echo "TARGETED_PODS=[${TARGETED_PODS_OUTPUT}]" >> $GITHUB_OUTPUT
  
  batch:
    needs: gather-info
    name: Batch
    uses: ./.github/workflows/tf-deploy.yml
    secrets: inherit
    with:
      location: ${{ matrix.pod }}
    strategy:
      max-parallel: ${{ fromJSON(needs.gather-info.outputs.MAX_PARALLEL) }}
      fail-fast: false
      matrix:
        pod: ${{ fromJSON(needs.gather-info.outputs.TARGETED_PODS) }}