Deploying AWS Lambda Using GitHub Actions

This guide explains how to automate the deployment of an AWS Lambda function using GitHub Actions. This setup allows your function to be updated automatically whenever you push changes to your GitHub repository.

What is this for?

AWS Lambda is a serverless compute service that runs your code in response to events.

GitHub Actions is a CI/CD (Continuous Integration/Continuous Deployment) tool that automates workflows, like deploying your code.

This guide will show you how to deploy your AWS Lambda function automatically whenever you push code to GitHub.

Prerequisites

Before starting, ensure you have:

• A GitHub account (Sign up)
• An AWS account (Sign up)

Step 1: Set Up AWS Lambda

Create an AWS Lambda Function

1. Go to AWS Lambda Console
2. Click Create function
3. Choose Author from scratch
4. Set the function name (e.g., myLambdaFunction)
5. Choose Python 3.x as the runtime
6. Under Permissions, choose Create a new role with basic Lambda permissions
7. Click Create function

Find Your Function & Region

1. Go to AWS Lambda Console
2. Click on your function
3. Check the region in the top-right corner (e.g., us-east-1)

Step 2: Set Up IAM User & Permissions

Create an IAM User for GitHub Actions

1. Go to AWS IAM Console
2. Click Users → Add user
3. Set the name (e.g., GitHubActionsUser)
4. Choose Programmatic access
5. Click Next and attach AWSLambdaFullAccess
6. Click Create user and download the Access Key & Secret Key

Store AWS Credentials in GitHub Secrets

1. Go to your GitHub repository
2. Click Settings → Secrets and variables → Actions
3. Click New repository secret
4. Add the following secrets:
   • AWS_ACCESS_KEY_ID → (Your AWS Access Key ID)
   • AWS_SECRET_ACCESS_KEY → (Your AWS Secret Access Key)

Step 3: Set Up GitHub Actions Workflow

Create the GitHub Actions Workflow File

1. In your GitHub repo, go to the /.github/workflows/ directory (or create it if it doesn't exist)
2. Create a new file named deploy-lambda.yml
3. Add the following content:

name: Deploy AWS Lambda

on:
  push:
    branches:
      - main

jobs:
  deploy:
    runs-on: ubuntu-latest
    steps:
      - name: Checkout code
        uses: actions/checkout@v3

      - name: Set up AWS credentials
        uses: aws-actions/configure-aws-credentials@v1
        with:
          aws-access-key-id: ${{ secrets.AWS_ACCESS_KEY_ID }}
          aws-secret-access-key: ${{ secrets.AWS_SECRET_ACCESS_KEY }}
          aws-region: us-east-1  # Change this to match your AWS region

      - name: Zip the Lambda function
        run: zip function.zip lambda_function.py

      - name: Deploy Lambda function
        run: |
          aws lambda update-function-code \
            --function-name myLambdaFunction \
            --zip-file fileb://function.zip

Commit and Push the Workflow

Add and commit the workflow file:

git add .github/workflows/deploy-lambda.yml
git commit -m "Added GitHub Actions for AWS Lambda"
git push origin main

Step 4: Deploy and Test

Push Code Changes to Trigger Deployment

Whenever you update lambda_function.py and push the changes to GitHub, the GitHub Actions workflow will automatically deploy your function.

Test the Lambda Function in AWS

1. Go to AWS Lambda Console
2. Click on your function myLambdaFunction
3. Click Test
4. Create a test event (default settings are fine)
5. Click Test again to execute the function

Check the response. If successful, you should see:

{
    "statusCode": 200,
    "body": "AWS Lambda Updated via GitHub Actions!"
}

Summary

What We Did

• Created an AWS Lambda function
• Set up IAM permissions & GitHub Secrets
• Configured GitHub Actions for deployment
• Successfully deployed AWS Lambda via GitHub Actions
• Tested and confirmed that deployments work

Now, every time you push a change to GitHub, your AWS Lambda function will be updated automatically.

FAQ

How do I update my Lambda function?

Just edit lambda_function.py and push the changes to GitHub. GitHub Actions will automatically redeploy the function.

What if the deployment fails?

• Check GitHub Actions logs for errors
• Ensure your IAM user has AWSLambdaFullAccess
• Make sure your AWS region is correct

Can I use other runtimes (Node.js, Java, etc.)?

Yes. Just change the runtime in AWS Lambda and update the function code accordingly.

Next Steps

• Add more functionality to your Lambda function
• Automate deployments for multiple Lambda functions
• Integrate with AWS API Gateway or other AWS services

Now you can easily deploy AWS Lambda with GitHub Actions.