Skip to main content

Documentation Index

Fetch the complete documentation index at: https://notes.kodekloud.com/llms.txt

Use this file to discover all available pages before exploring further.

GitHub Actions lets you reuse common CI/CD logic across multiple workflows and repositories. Instead of duplicating identical deployment steps in both dev-deploy and prod-deploy, extract them into a single reusable workflow.

​
Why Avoid Duplication?

A typical “Solar System Workflow” might look like this: 
# .github/workflows/solar-system.yml
name: Solar System Workflow

on:
  workflow_dispatch:
    branches:
      - main
      - 'feature/*'

env:
  MONGO_URI: 'mongodb+srv://supercluster.d83jj.mongodb.net/superData'
  MONGO_USERNAME: ${{ vars.MONGO_USERNAME }}
  MONGO_PASSWORD: ${{ secrets.MONGO_PASSWORD }}

jobs:
  unit-testing: …
  code-coverage: …
  docker: …
  dev-deploy: …
  dev-integration-testing: …
  prod-deploy: …
  prod-integration-testing: …
Maintaining nearly identical steps in dev-deploy and prod-deploy quickly becomes error-prone. Use reusable workflows to centralize your logic.
See the official documentation for an overview of reusing workflows in GitHub Actions.
The image shows a GitHub Docs page about GitHub Actions, specifically focusing on the limitations of reusing workflows. It includes a navigation menu on the left and a list of related topics on the right.

​
1. Create the Reusable Workflow

  1. File location: .github/workflows/reuse-deployment.yml
  2. Trigger: replace on: workflow_dispatch with on: workflow_call.
  3. Inputs: declare kubeconfig as a required string.
# .github/workflows/reuse-deployment.yml
name: Deployment – Reusable Workflow

on:
  workflow_call:
    inputs:
      kubeconfig:
        description: 'Kubernetes config for the target cluster'
        required: true
        type: string

​
Full Workflow Definition

# .github/workflows/reuse-deployment.yml
name: Deployment – Reusable Workflow

on:
  workflow_call:
    inputs:
      kubeconfig:
        description: 'Kubernetes config for the target cluster'
        required: true
        type: string

jobs:
  reuse-deploy:
    runs-on: ubuntu-latest
    environment:
      name: development          # Can be overridden by caller
      url: https://${{ steps.set-ingress-host.outputs.APP_INGRESS_HOST }}
    outputs:
      APP_INGRESS_URL: ${{ steps.set-ingress-host.outputs.APP_INGRESS_HOST }}

    steps:
      - name: Checkout repository
        uses: actions/checkout@v4

      - name: Install kubectl CLI
        uses: azure/setup-kubectl@v3
        with:
          version: 'v1.26.0'

      - name: Set Kubeconfig
        uses: azure/k8s-set-context@v3
        with:
          method: kubeconfig
          kubeconfig: ${{ inputs.kubeconfig }}

      - name: Fetch cluster details
        run: |
          kubectl version --short
          echo '---'
          kubectl get nodes

      - name: Save Nginx Ingress Controller IP to GITHUB_ENV
        run: |
          echo "INGRESS_IP=$(kubectl -n ingress-nginx \
            get svc ingress-nginx-controller \
            -o jsonpath='{.status.loadBalancer.ingress[0].ip}')" >> $GITHUB_ENV

      - name: Replace tokens in manifest files
        uses: cschleiden/replace-tokens@v1
        with:
          tokenPrefix: '_'
          tokenSuffix: '_'
          files: ['kubernetes/development/*.yaml']
        env:
          NAMESPACE: ${{ vars.NAMESPACE }}
          REPLICAS: ${{ vars.REPLICAS }}
          DOCKER_IMAGE: ${{ vars.DOCKER_IMAGE }}

      - name: Create MongoDB secret
        run: |
          kubectl -n ${{ vars.NAMESPACE }} create secret generic mongo-db-creds \
            --from-literal=MONGO_URI=${{ vars.MONGO_URI }} \
            --from-literal=MONGO_USERNAME=${{ vars.MONGO_USERNAME }} \
            --from-literal=MONGO_PASSWORD=${{ secrets.MONGO_PASSWORD }} \
            --save-config --dry-run=client -o yaml | kubectl apply -f -

      - name: Deploy to development
        run: |
          kubectl apply -f kubernetes/development

      - name: Set application ingress host URL
        id: set-ingress-host
        run: |
          echo "APP_INGRESS_HOST=$(kubectl -n ${{ vars.NAMESPACE }} \
            get ingress -o jsonpath='{.items[0].spec.tls[0].hosts[0]}')" >> "$GITHUB_OUTPUT"

​
2. Call the Reusable Workflow

Replace the inline dev-deploy and prod-deploy jobs in your main pipeline: 
# .github/workflows/solar-system.yml
name: Solar System Workflow

on:
  workflow_dispatch:
    branches:
      - main
      - 'feature/*'

env:
  MONGO_URI: 'mongodb+srv://supercluster.d83jj.mongodb.net/superData'
  MONGO_USERNAME: ${{ vars.MONGO_USERNAME }}
  MONGO_PASSWORD: ${{ secrets.MONGO_PASSWORD }}

jobs:
  unit-testing: …
  code-coverage: …
  docker: …

  dev-deploy:
    if: contains(github.ref, 'feature/')
    needs: docker
    uses: ./.github/workflows/reuse-deployment.yml
    with:
      kubeconfig: ${{ secrets.KUBECONFIG }}

  dev-integration-testing: …

  prod-deploy:
    if: github.ref == 'refs/heads/main'
    needs: docker
    uses: ./.github/workflows/reuse-deployment.yml
    with:
      kubeconfig: ${{ secrets.KUBECONFIG }}

  prod-integration-testing: …
Original JobReusable Workflow Call
dev-deployuses: ./.github/workflows/reuse-deployment.yml
prod-deployuses: ./.github/workflows/reuse-deployment.yml
The image shows a GitHub Actions workflow interface with a series of jobs and their statuses, including unit testing, code coverage, and deployment steps. The workflow is titled "modified path of reusable workflow" and is currently in a waiting status.

​
3. Troubleshoot Missing Inputs

If your pipeline fails with: 
Input required and not supplied: kubeconfig
it indicates that the caller did not pass the required kubeconfig input.
The image shows a GitHub Actions workflow with a failed job in the "dev-deploy" stage due to a missing "kubeconfig" input. Other stages like unit testing and code coverage are marked as successful.
Always pass all required inputs when calling a reusable workflow:
with:
  kubeconfig: ${{ secrets.KUBECONFIG }}

​
References

Watch Video