GitHub Actions can be used to do something whenever something happens in one of your GitHub repositories. If you are not familiar with GitHub Actions, check out my article Getting Started with GitHub Actions.

strategy matrix can be used to loop over a list of items. In this example, main-job will run three times, the first time echo apple, and second time echo banana, the third time echo watermelon.

name: my workflow
run-name: ${{ github.workflow }} run by ${{ github.actor }}
on:
  workflow_dispatch:
jobs:
  main-job:
    runs-on: [self-hosted, linux]
    strategy:
      matrix:
        fruits: ['apple', 'banana', 'watermelon']
    steps:
      - run: echo "${{ matrix.fruits }}"

For more complex scenarios, you may need to define JSON that contains the items you want to loop.

name: my workflow
run-name: ${{ github.workflow }} run by ${{ github.actor }}
on:
  workflow_dispatch:
jobs:
  job1:
    runs-on: ubuntu-latest
    outputs:
      food: ${{ steps.xfood.outputs.food }}
    steps:
      - name: define food as a JSON list
        id: xfood
        run: echo "food={'include':[{'fruit':'apple','veggy':'pepper'}]}" >> $GITHUB_OUTPUT 

  job2:
    runs-on: ubuntu-latest
    needs: job1
    strategy:
      fail-fast: false
      matrix: ${{ fromJSON(needs.job1.outputs.food) }}
    steps:
      # This should return: {fruit: apple, veggy: pepper}
      - name: full JSON
        run: echo "${{ toJSON(matrix) }}"

      # This should return apple
      - name: matrix.fruit
        run: echo "${{ toJSON(matrix.fruit) }}"  

      # This should return pepper
      - name: matrix.veggy
        run: echo "${{ toJSON(matrix.veggy) }}"