Demo Lambda Invoke Function

In this lesson, we’ll extend our Jenkins pipeline to invoke an AWS Lambda function automatically after deployment. Instead of copying the function URL from the console by hand, we’ll fetch it dynamically using the AWS CLI and validate the /live endpoint. This streamlines your CI/CD process and ensures your function is responding as expected.

Inspecting the Lambda Function in the Console

Before automating, you can view your function’s public URL and settings in the AWS Lambda console:

Retrieving the Function URL via AWS CLI

AWS provides the get-function-url-config command to programmatically retrieve a function’s URL configuration. For full details, see the AWS Lambda CLI command reference.

Parsing the JSON Response

When you run:

aws lambda get-function-url-config --function-name solar-system-function

you receive a JSON object containing:

Jenkins Pipeline Stage: Lambda Invocation

Below is a Groovy stage that runs on the main branch. It:

1. Uses AWS credentials stored in Jenkins.
2. Waits 30 seconds for the Lambda update to propagate.
3. Fetches and normalizes the FunctionUrl.
4. Sends a HEAD request to the /live endpoint and checks for a 200 OK response.

stage('Lambda - Invoke Function') {
    when {
        branch 'main'
    }
    steps {
        withAWS(credentials: 'aws-s3-ec2-lambda-creds', region: 'us-east-2') {
            sh '''
            # Wait for Lambda to stabilize
            sleep 30s

            # Fetch the function URL configuration
            function_url_data=$(aws lambda get-function-url-config --function-name solar-system-function)

            # Extract and normalize the FunctionUrl
            function_url=$(echo $function_url_data | jq -r '.FunctionUrl | sub("/$"; "")')

            # Send a HEAD request to the /live endpoint and check for 200 OK
            curl -Is $function_url/live | grep -i "200 OK"
            '''
        }
    }
}

Sample JSON Output

{
  "FunctionArn": "arn:aws:lambda:us-east-2:604513224291:function:solar-system-function",
  "FunctionUrl": "https://gxl2znysqzkhp116766t29be5d9e0jcjm.lambda-url.us-east-2.on.aws/",
  "AuthType": "NONE",
  "Cors": {
    "AllowOrigins": ["*"]
  },
  "CreationTime": "2024-10-01T12:27:05.4573487",
  "LastModifiedTime": "2024-10-01T12:27:05.4573487",
  "InvokeMode": "BUFFERED"
}

Verifying with curl

You can manually test the live endpoint:

curl -Is https://gxl2znysqzkhp116766t29be5d9e0jcjm.lambda-url.us-east-2.on.aws/live

Expected response:

HTTP/1.1 200 OK
Date: Wed, 02 Oct 2024 08:37:51 GMT
Content-Type: application/json; charset=utf-8
Content-Length: 0
Connection: keep-alive
x-amzn-RequestId: b136587b-839f-4904-ad01-032e778b5709
access-control-allow-origin: *
etag: W/"11-oM4ub/mwEIvBYTxJnDIjZC9y6"
x-powered-by: Express
X-Amzn-Trace-Id: Root=1-66fd065f-19a457cb200ddba664c780a;Parent=04f1e27712579323;Sampled=0;Lineage=1:ea66bb95:0

Pipeline Execution Results

In the Jenkins UI, you’ll see the Lambda invocation stage after any tests:

With this setup, every push to main will automatically confirm that your Lambda function is live and returning the expected HTTP status, fully automating post-deployment validation.

Links and References

• AWS Lambda CLI Reference
• Jenkins Pipeline: AWS Steps Plugin
• OWASP Dependency-Check
• Jenkins Declarative Pipeline Syntax