Skip to content

README.md

Latest commit

 

History

History
129 lines (93 loc) · 3.87 KB

README.md

File metadata and controls

129 lines (93 loc) · 3.87 KB

Serverless Health Check API with CI/CD

The goal of this project is to build, configure, and automate the deployment of a simple serverless application on AWS. Created a health check endpoint that logs requests and stores them in a database, with a CI/CD pipeline to manage deployments for both staging and production environments, fully provisioned via Terraform and deployed automatically using GitHub Actions.

Architectural desig

Core Components

  • Amazon API Gateway (HTTP API)
  • AWS Lambda (Python)
  • Amazon DynamoDB
  • AWS IAM
  • Amazon CloudWatch Logs

Each environment (staging, prod) is isolated by naming convention and Terraform variables.

Runtime Request Flow

  1. Client: sends a GET or POST request to:
https://<api-id>.execute-api.<region>.amazonaws.com/health
  1. API Gateway:
  • Matches the /health route
  • Forwards the request using AWS_PROXY integration
  1. Lambda Function (env-health-check-function):
  • Logs the full request event to CloudWatch Logs
  • Generates a UUID
  • Stores request metadata in DynamoDB (env-requests-db)
  • Returns a JSON response
  1. DynamoDB:
  • Stores the request record (ID, timestamp, request payload)

Pipeline Flow

  1. Developer pushes code
  • staging branch → auto deploy
  • main branch → production deploy
  1. GitHub Actions workflow: The GitHub action workflow contain both terraform deploy and terraform destroy.

  • Configures AWS credentials (GitHub Secrets)

  • Terraform deploy - deploy.yaml

    • Checks out code
    • Runs:
      • terraform fmt
      • terraform validate
      • terraform plan
      • terraform apply

  • Terraform destroy - destroy.yaml

    • On GitHub console, manually trigger the destroy pipeline from the actions
    • Runs:
      • terraform int
      • terraform destroy

Environment separation

Aspect Staging Production
Branch staging main
Terraform vars staging.tfvars prod.tfvars
Lambda staging-health-check-function prod-health-check-function
DynamoDB staging-requests-db prod-requests-db
API Gateway staging-health-check-api prod-health-check-api
Approval None Required

Security and IAM Role

Each Lambda function has one dedicated IAM role with:

  • Allowed permissions
    • dynamodb:PutItem → specific DynamoDB table ARN
    • logs:CreateLogGroup
    • logs:CreateLogStream
    • logs:PutLogEvents
  • Denied by default
    • No read access to DynamoDB
    • No access to other AWS services
    • No wildcard write permissions
  • secrets Handling
    • AWS credentials stored in GitHub Secrets
    • No credentials committed to repository

create hello lambda funtion using Python

# Hello lambda function
def lambda_handler(event, context):
    name = event.get("name", "World")
    message = f"Hello, {name}!"

    return {
        "statusCode": 200,
        "body": message
    }

# Run the funtion locally for testing
if __name__ == "__main__":
    test_event = {"name": "Emmanuel Ogah"} 
    result = lambda_handler(test_event, None)
    print(result)

Run the python funtion locally using VS Code Run Button

  • Click the “Run Python File” button in the top right corner.
# Output

{'statusCode': 200, 'body': 'Hello, Emmanuel Ogah!'}"

  • Create the terraform folder structure

  • Deploy with: terraform init then terraform apply -var-file="staging.tfvars" (or prod.tfvars)

endpoint - https://nrbefv9bcj.execute-api.us-east-1.amazonaws.com/health

terraform init -backend-config=backend-staging.tfvars for staging environment

terraform init -backend-config=backend-prod.tfvars for prod environment