Reusing GitHub Actions Workflows with Workflow Call

GitHub Actions provides a robust platform for automating workflows directly in your GitHub repositories. For larger projects with complex workflows, you might find that you have repeating segments of code in your workflows. Duplicating code is rarely a good idea as it leads to maintenance headaches and can result in errors. The “workflow call” feature in GitHub Actions is a way to promote reuse and reduce duplication. This blog post will guide you through the process of including one workflow.yaml into another using this feature.

Understanding Workflow Calls in GitHub Actions

GitHub Actions introduced the workflow call syntax to allow the reuse of workflows across different repositories. You can call a workflow and pass inputs to it. You can also use outputs from the called workflow in your calling workflow.

A workflow that will be used in a workflow call is written as any other workflow, but with the inclusion of the inputs and outputs keys to accept inputs and produce outputs.

Creating a Reusable Workflow

Let’s create a reusable workflow that we’ll call from another workflow. We’ll create a workflow that lints our JavaScript code.

In your repository, create a new workflow file named lint-code.yml:

name: Lint Code

on:
  workflow_call:

jobs:
  lint:
    runs-on: ubuntu-latest
    steps:
      - name: Checkout repository
        uses: actions/checkout@v2

      - name: Use Node.js
        uses: actions/setup-node@v2
        with:
          node-version: 14

      - name: Install dependencies
        run: npm ci

      - name: Run linter
        run: npm run lint

name: Lint Code

on:

workflow_call:

jobs:

lint:

runs-on: ubuntu-latest

steps:

- name: Checkout repository

uses: actions/checkout@v2

- name: Use Node.js

uses: actions/setup-node@v2

with:

node-version: 14

- name: Install dependencies

run: npm ci

- name: Run linter

run: npm run lint

In this workflow, on: workflow_call means that this workflow is designed to be called from other workflows.

Calling a Workflow from Another Workflow

Now, let’s create another workflow that will call our lint-code.yml workflow:

name: Build and Test

on: [push, pull_request]

jobs:
  call-linter:
    uses: ./.github/workflows/lint-code.yml
    secrets:
      github_token: ${{ secrets.GITHUB_TOKEN }}

name: Build and Test

on: [push, pull_request]

jobs:

call-linter:

uses: ./.github/workflows/lint-code.yml

secrets:

github_token: ${{ secrets.GITHUB_TOKEN }}

In this workflow, uses: ./.github/workflows/lint-code.yml indicates that we’re calling the lint-code.yml workflow located in the .github/workflows/ directory of the current repository.

Conclusion

GitHub Actions’ “workflow call” syntax is a powerful feature that enables you to reuse workflows across your repository, promoting code reuse and reducing duplication. You can use it to create workflows that handle common tasks and call them from other workflows, creating a modular and maintainable CI/CD setup.