Trigger a GitHub Actions workflow when a folder changes

Recently I've been working with GitHub and creating a lot of workflows.  I have a couple of GitHub repositories that store both software code and infrastructure as code.  

Every time I made a change to the software code, it would trigger the infrastructure part as well, and I was not too fond of the fact that my infrastructure was re-deploying every time I made a change to the software.

I found a solution to my problem - GitHub Actions triggers!

What is an GitHub Actions workflow?

Within GitHub, a GitHub Actions workflow is an automated process that can be set up within your repositories. A GitHub Actions workflow can automate tasks and jobs for you.  It can help you build your Continuous Integration/Continuous Delivery (CI/CD) pipelines.

GitHub Actions triggers

When you create a GitHub Action, you can specify when it runs, this is called a trigger.  You can identify triggers, such as when new code is pushed to the repository or when a pull request is actioned, the workflow will spin into action.  

Usually, these triggers are set to kick off when a change happens to a specific branch.  But you can take that down another level.  You can specify if a change occurs to a particular directory or path within a branch, and the workflow will kick start.

In this example below, you can see the start of a workflow where the workflow will be triggered when changes are pushed into the folder "MyFirstFolder" within the central repository.

name: Workflow example

on:

  push:
    branches:
    - main
    paths:
    - MyFirstFolder
    

jobs:

  build:
 

If changes are made out with the "MyFirstFolder", the workflow won't be triggered.

What this means is you can have workflows for different purposes within your repository.  As I mentioned earlier means, I can store my software code and infrastructure as code within a GitHub repository, with different workflows for each only being triggered when I make a change to that specific code.

Wildcard Triggers

But you can also be less specific than using a folder name.  Below is a small example where you specify a file type, this time an Azure Bicep file, to be the trigger for the workflow.

name: Workflow example

on:

  push:
    paths:
    - '**.bicep'
    

jobs:

  build:

Excluding paths

You could do it another way by excluding folders.  In the example below on, push events that include at least one file outside the MyFirstFolder directory.

name: Workflow example

on:

  push:
    paths-ignore:
      - 'MyFirstFolder/**'
    

jobs:

  build:

There is a lot of flexibility with GitHub Action workflows and making them trigger.  So try it out, experiment and make workflows work for you. 😉