go-lambda

README

go-lambda

AWS has deprecated go1.x runtime.

This repository contains example lambda handler integration with API gateway. Terraform is used to deploy infrastructure including DNS, SSL Certificates.

Requirements

• go 1.20
• zip
• docker
• terraform
• aws cli

Setup (optional)

Docker

Although not require specifically to run go in lambdas, can be useful to avoid compatibility issues when using cgo bindings or third party libraries using cgo such as sqlite3.

• build docker container for building lambda function binary fully compatible with aws lambda runtime
• docker build -t lambda-build .

Build

AWS provided.al2 requires executables to be named bootstrap.

• GOARCH=amd64 GOOS=linux go build -tags lambda.norpc -o ./infrastructure/bootstrap main.go

  • provided.al2 provide a single process architecture and allow running without RPC dependency using -tags lambda.norpc
  • Build without RPC using GOARCH=amd64 GOOS=linux go build -tags lambda.norpc -o ./infrastructure/bootstrap main.go

• go build -o ./bin/main.local ./cmd/handler/main.go for locally running lambda handler as a cli application.

  • requires manually providing event data from file or hard coded into the main.go file
  • it can be very easy to write a cli interface to read event from path or stdin or wrap in a http server

Deploy

Create a terraform.tfvars file inside infrastructure folder and fill out required variables.

• Manually deploy function code changes with cli aws lambda update-function-code --function-name go-lambda --zip-file fileb://bootstrap.zip
• Use terraform to deploy infrastructure changes and function changes terraform apply --auto-approve
  • main.aws_lambda_function.go_lambda.source_code_hash = filebase64sha256("bootstrap.zip") will ensure new builds to redeploy with infrastructure changes.

Optional

Currently, the lambda handler takes in any request method and path. For full utilization of api gateway proxy functionality you can make use of https://github.com/awslabs/aws-lambda-go-api-proxy to run a standard Go http server and adapt api gateway requests to Go requests and vice versa Go responses to api gateway responses

• Be aware to write lambda aware handlers using the adapters.
• Optimize for fast startups

Future work

• add GitHub action to build and deploy changes on main branch merge