Automatically Trigger GitHub Actions Workflow on Specific File or Directory Changes
Introduction
GitHub Actions enable developers to automate software development workflows directly within a GitHub repository. One useful feature of GitHub Actions is the ability to trigger workflows based on changes to specific files or directories. This guide explains how to configure GitHub Actions workflows to start automatically when there are changes to a specified file or directory.
Overview of GitHub Actions
GitHub Actions is a CI/CD platform where workflows can react to various events in a repository. Workflows are defined in YAML files, located in the .github/workflows directory of your repository. These files define when and how the workflows are run.
Triggering a Workflow on Changes to Specific Files
With GitHub Actions, you can configure your workflows to run when changes are made to specific files or directories. This can be very useful, for instance, when you want to run tests only when changes are made to source code files or rebuild your website only when markdown files are updated.
Step 1: Create a Workflow YAML File
To begin with, create a new YAML file within the .github/workflows directory of your repository. This file will contain your workflow configuration. Let’s call it file-change-workflow.yml.
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name: File Change Workflow |
The name field gives your workflow a name, which will be displayed on your repository’s actions page.
Step 2: Define the on Field
Next, you need to define the on field to specify the events that trigger the workflow. For our purpose, we use the push event with a paths filter to trigger the workflow only when changes are made to certain files or directories.
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on: push: paths: - 'src/**' |
Here, the paths filter is used to specify which files or directories to monitor for changes. The 'src/**' pattern indicates that the workflow should be triggered on push events that include changes to any files in the src directory or its subdirectories.
Step 3: Define the jobs Field
Finally, define what your workflow does using the jobs field. In this example, we will print a message saying that a change has been detected.
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jobs: build: runs-on: ubuntu-latest steps: - name: A change was detected in the src directory run: echo "A change was detected in the src directory!" |
Here, we define a single job named build that runs on the latest version of Ubuntu. The job includes one step that prints a message indicating that a change has been detected in the src directory.
The Complete Workflow
After combining all the steps, our complete workflow file looks like this:
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name: File Change Workflow on: push: paths: - 'src/**' jobs: build: runs-on: ubuntu-latest steps: - name: A change was detected in the src directory run: echo "A change was detected in the src directory!" |
With this configuration, the workflow will be triggered whenever a push event includes changes to any file in the src directory or its subdirectories.
Conclusion
GitHub Actions’ ability to trigger workflows based on changes to specific files or directories is a powerful feature for streamlining your CI/CD pipeline. It can help you run relevant tests, build, or deployment workflows based on the nature and location of the changes in your repository.
Always remember that your workflows’ complexity should be tailored to your project’s needs. GitHub Actions provide a flexible and powerful tool for automating your software development workflows.