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AWS Lambda is a powerful serverless computing service that allows you to run backend code without managing servers. Using Go for AWS Lambda functions offers high performance and efficiency, especially when building APIs. While existing handlers like `lambda-go-api-proxy` simplify integration, creating a custom HTTP router from scratch provides deeper control and optimization.
In this article, we explore a custom Lambda API implementation in Go, demonstrating how to build an HTTP router without relying on third-party libraries.
You Should Know:
1. Setting Up a Go Lambda Function
To begin, initialize a Go module and install the AWS Lambda Go SDK:
go mod init lambda-router go get github.com/aws/aws-lambda-go/lambda
2. Building a Custom HTTP Router
The core logic involves parsing API Gateway requests and routing them to appropriate handlers. Below is a simplified example:
package main
import (
"context"
"fmt"
"github.com/aws/aws-lambda-go/events"
"github.com/aws/aws-lambda-go/lambda"
)
func handler(ctx context.Context, request events.APIGatewayProxyRequest) (events.APIGatewayProxyResponse, error) {
switch request.Path {
case "/users":
return handleUsers(request)
case "/posts":
return handlePosts(request)
default:
return events.APIGatewayProxyResponse{
StatusCode: 404,
Body: "Not Found",
}, nil
}
}
func handleUsers(request events.APIGatewayProxyRequest) (events.APIGatewayProxyResponse, error) {
return events.APIGatewayProxyResponse{
StatusCode: 200,
Body: "User Endpoint",
}, nil
}
func handlePosts(request events.APIGatewayProxyRequest) (events.APIGatewayProxyResponse, error) {
return events.APIGatewayProxyResponse{
StatusCode: 200,
Body: "Post Endpoint",
}, nil
}
func main() {
lambda.Start(handler)
}
3. Deploying the Lambda Function
Use the AWS CLI to deploy the function:
GOOS=linux GOARCH=amd64 go build -o main zip function.zip main aws lambda create-function --function-name go-lambda-router --runtime go1.x --handler main --zip-file fileb://function.zip --role YOUR_LAMBDA_ROLE_ARN
4. Testing with API Gateway
Create a REST API in AWS API Gateway and integrate it with the Lambda function. Test using curl:
curl https://YOUR_API_GATEWAY_URL/users
What Undercode Say:
Building a custom HTTP router for AWS Lambda in Go provides flexibility and performance benefits. Key takeaways:
– Efficient Routing: Avoid unnecessary dependencies by implementing lightweight routing.
– Scalability: Lambda automatically scales with incoming requests.
– Cost-Effective: Pay only for the compute time used.
For further optimization:
- Use AWS SAM for deployment:
sam deploy --guided
- Monitor performance with AWS CloudWatch:
aws logs tail /aws/lambda/go-lambda-router --follow
Expected Output:
A fully functional Go-based AWS Lambda HTTP router, deployable via AWS CLI and integrable with API Gateway.
Reference: Writing an HTTP router for AWS Lambda functions from scratch with Go
References:
Reported By: Darryl Ruggles – Hackers Feeds
Extra Hub: Undercode MoN
Basic Verification: Pass ✅
