Execute github actions workflow/job in directory where code was changed-CodePudding

I am trying to implement a github actions workflow with a job which will plan and apply my terraform code changes only for directory where changes were made. The problem I am currently facing is that I can't figure out how to switch directories so that terraform plan is executed from a directory where code has been updated/changed.

I have a monorepo setup which is as follow:

repo
  tf-folder-1
  tf-folder-2
  tf-folder-3

Each folder contains an independent terraform configuration. So, for example I would like run a workflow only when files change inside tf-folder-1. Such workflow needs to switch to working directory which is tf-folder-1 and then run terraform plan/apply.

jobs:
  terraform:
    name: "Terraform"
    runs-on: ubuntu-latest
  defaults:
    run:
      working-directory: ./tf-folder-1
  steps:
    - name: Checkout
      uses: actions/checkout@v3     

    - name: Configure AWS credentials from Test account
      uses: aws-actions/configure-aws-credentials@v1
      with:
        role-to-assume: arn:aws:iam::000000000000000:role/deploy-role
        aws-region: eu-west-2

    - name: Setup Terraform
      uses: hashicorp/setup-terraform@v2
    ...

So far, I have the above terraform job but it only runs for statically defined working-directory. It doesn't work with a use case where it should run the workflow when changes happen within specific folder. Can someone advise how to fix this pipeline?

Thanks

CodePudding user response：

GitHub Actions has path filtering you can take advantage of when you are working with workflows that are triggered off a push or push_request event.

For example say you have a monorepo with the directories, tf_1, tf_2, and tf_3. You can do something like below for when changes occur to the directory tf_1.

name: Demonstrate GitHub Actions on Monorepo 
on:
  push:
    branches:
      - master
    paths:
      - 'tf_1/**'

defaults:
  run:
    working-directory: tf_1 

jobs:
  build:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v1

For more details on path filtering, please refer to the GitHub Actions syntax documentation.

CodePudding user response：

You can use a GitHub action that outputs the directories where the files have changed/modified, for example, this one: Changed-files or even perform the calculation with a shell step using git diff.

If you use the GHA suggested you can set the input dir_names to true, which would output unique changed directories instead of filenames, based on the results of that you can change the directory to run your Terraform operations.