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 1.22
• zip
• docker
• terraform
• aws cli
• jq

Setup (Optional)

For now an existing AWS ECR is required to exist already or created using ./create_ecr.sh. Unfortunately it's not possible yet to create an ECR, build and push an image, then reference the image_uri needed for Lambda resource.

If you an existing ECR you can run ./create_ecr.sh with the --auth-only flag to skip creating a new ECR. This will pull credentials and inject into Docker engine.

Usage: ./create-ecr.sh --repo-name NAME --region REGION --account-id ID [--auth-only]
  --repo-name    ECR repository name         (required)
  --region       AWS region                  (required)
  --account-id   AWS account ID              (required)
  --auth-only    Only login Docker to ECR and exit

Build

The deploy artifact is a container image instead of a zip file with the built binary. AWS has optimized container images for Lambda and results in faster cold starts.

To build an image and tag using tag --points-at HEAD --sort=-version:refname run ./build_image.sh. This script will built a Lambda compatible container image and push to the configured AWS ECR. This script expects ./create_ecr.sh to have run or at the minimum run with --auth-only for an existing ECR to get login credentials for Docker engine.

Usage: ./build_image.sh --account-id ID --region REGION --repo-name NAME [--tag TAG]
  --account-id   AWS account ID       (required)
  --region       AWS region           (required)
  --repo-name    ECR repository name  (required)
  --tag          Image tag override; if omitted, use latest Git tag on HEAD

If you want to create and push smaller slim images then please install slimtoolkit/slim. You can then optionally pass --slim-image to minify images and push to ECR.

Deploy

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

• Use terraform to deploy infrastructure changes and function changes terraform apply --auto-approve

To enable auto container image builds set with_docker_build to true. This will run the ./build_image.sh script and output the image URI for use in the Lambda resource. Default is disabled.

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