AWS Lambda

ko can build images that can be deployed as AWS Lambda functions, using Lambda's container support.

For best results, use the Go runtime interface client provided by the lambda package.

For example:

package main

import (
    "context"
    "fmt"
    "github.com/aws/aws-lambda-go/lambda"
)

type Event struct {
    Name string `json:"name"`
    // TODO: add other request fields here.
}

func main() {
    lambda.Start(func(ctx context.Context, event Event) (string, error) {
        return fmt.Sprintf("Hello %s!", event.Name), nil
    })
}

See AWS's documentation for more information on writing Lambda functions in Go.

To deploy to Lambda, you must push to AWS Elastic Container Registry (ECR):

KO_DOCKER_REPO=[account-id].dkr.ecr.[region].amazonaws.com/my-repo
image=$(ko build ./cmd/app)

Then, create a Lambda function using the image in ECR:

aws lambda create-function \
  --function-name hello-world \
  --package-type Image \
  --code ImageUri=${image} \
  --role arn:aws:iam::[account-id]:role/lambda-ex

See AWS's documentation for more information on deploying Lambda functions using Go container images, including how to configure push access to ECR, and how to configure the IAM role for the function.

The base image that ko uses by default supports both x86 and Graviton2 architectures.

You can also use the ko Terraform provider to build and deploy Lambda functions as part of your IaC workflow, using the aws_lambda_function resource. See the provider example to get started.