Deploy transpiled TypeScript code in Lambda with container images - AWS Lambda

Deploy transpiled TypeScript code in Lambda with container images

You can deploy your TypeScript code to an AWS Lambda function as a Node.js container image. AWS provides base images for Node.js to help you build the container image. These base images are preloaded with a language runtime and other components that are required to run the image on Lambda. AWS provides a Dockerfile for each of the base images to help with building your container image.

If you use a community or private enterprise base image, you must add the Node.js runtime interface client (RIC) to the base image to make it compatible with Lambda.

Lambda provides a runtime interface emulator for local testing. The AWS base images for Node.js include the runtime interface emulator. If you use an alternative base image, such as an Alpine Linux or Debian image, you can build the emulator into your image or install it on your local machine.

Using a Node.js base image to build and package TypeScript function code

To complete the steps in this section, you must have the following:

To create an image from an AWS base image for Lambda
  1. On your local machine, create a project directory for your new function.

  2. Create a new Node.js project with npm or a package manager of your choice.

    npm init
  3. Add the @types/aws-lambda and esbuild packages as development dependencies. The @types/aws-lambda package contains the type definitions for Lambda.

    npm install -D @types/aws-lambda esbuild
  4. Add a build script to the package.json file.

    "scripts": { "build": "esbuild index.ts --bundle --minify --sourcemap --platform=node --target=es2020 --outfile=dist/index.js" }
  5. Create a new file called index.ts. Add the following sample code to the new file. This is the code for the Lambda function. The function returns a hello world message.

    Note

    The import statement imports the type definitions from @types/aws-lambda. It does not import the aws-lambda NPM package, which is an unrelated third-party tool. For more information, see aws-lambda in the DefinitelyTyped GitHub repository.

    import { Context, APIGatewayProxyResult, APIGatewayEvent } from 'aws-lambda'; export const handler = async (event: APIGatewayEvent, context: Context): Promise<APIGatewayProxyResult> => { console.log(`Event: ${JSON.stringify(event, null, 2)}`); console.log(`Context: ${JSON.stringify(context, null, 2)}`); return { statusCode: 200, body: JSON.stringify({ message: 'hello world', }), }; };
  6. Create a new Dockerfile with the following configuration:

    • Set the FROM property to the URI of the base image.

    • Set the CMD argument to specify the Lambda function handler.

    The following example Dockerfile uses a multi-stage build. The first step transpiles the TypeScript code into JavaScript. The second step produces a container image that contains only JavaScript files and production dependencies.

    Note that the example Dockerfile does not include a USER instruction. When you deploy a container image to Lambda, Lambda automatically defines a default Linux user with least-privileged permissions. This is different from standard Docker behavior which defaults to the root user when no USER instruction is provided.

    Example Dockerfile
    FROM public.ecr.aws/lambda/nodejs:20 as builder WORKDIR /usr/app COPY package.json index.ts ./ RUN npm install RUN npm run build FROM public.ecr.aws/lambda/nodejs:20 WORKDIR ${LAMBDA_TASK_ROOT} COPY --from=builder /usr/app/dist/* ./ CMD ["index.handler"]
  7. Build the Docker image with the docker build command. The following example names the image docker-image and gives it the test tag.

    docker build --platform linux/amd64 -t docker-image:test .
    Note

    The command specifies the --platform linux/amd64 option to ensure that your container is compatible with the Lambda execution environment regardless of the architecture of your build machine. If you intend to create a Lambda function using the ARM64 instruction set architecture, be sure to change the command to use the --platform linux/arm64 option instead.

  1. Start the Docker image with the docker run command. In this example, docker-image is the image name and test is the tag.

    docker run --platform linux/amd64 -p 9000:8080 --read-only docker-image:test

    This command runs the image as a container and creates a local endpoint at localhost:9000/2015-03-31/functions/function/invocations.

    Note

    If you built the Docker image for the ARM64 instruction set architecture, be sure to use the --platform linux/arm64 option instead of --platform linux/amd64.

  2. From a new terminal window, post an event to the local endpoint.

    Linux/macOS

    In Linux and macOS, run the following curl command:

    curl "http://localhost:9000/2015-03-31/functions/function/invocations" -d '{}'

    This command invokes the function with an empty event and returns a response. If you're using your own function code rather than the sample function code, you might want to invoke the function with a JSON payload. Example:

    curl "http://localhost:9000/2015-03-31/functions/function/invocations" -d '{"payload":"hello world!"}'
    PowerShell

    In PowerShell, run the following Invoke-WebRequest command:

    Invoke-WebRequest -Uri "http://localhost:9000/2015-03-31/functions/function/invocations" -Method Post -Body '{}' -ContentType "application/json"

    This command invokes the function with an empty event and returns a response. If you're using your own function code rather than the sample function code, you might want to invoke the function with a JSON payload. Example:

    Invoke-WebRequest -Uri "http://localhost:9000/2015-03-31/functions/function/invocations" -Method Post -Body '{"payload":"hello world!"}' -ContentType "application/json"
  3. Get the container ID.

    docker ps
  4. Use the docker kill command to stop the container. In this command, replace 3766c4ab331c with the container ID from the previous step.

    docker kill 3766c4ab331c
To upload the image to Amazon ECR and create the Lambda function
  1. Run the get-login-password command to authenticate the Docker CLI to your Amazon ECR registry.

    • Set the --region value to the AWS Region where you want to create the Amazon ECR repository.

    • Replace 111122223333 with your AWS account ID.

    aws ecr get-login-password --region us-east-1 | docker login --username AWS --password-stdin 111122223333.dkr.ecr.us-east-1.amazonaws.com
  2. Create a repository in Amazon ECR using the create-repository command.

    aws ecr create-repository --repository-name hello-world --region us-east-1 --image-scanning-configuration scanOnPush=true --image-tag-mutability MUTABLE
    Note

    The Amazon ECR repository must be in the same AWS Region as the Lambda function.

    If successful, you see a response like this:

    { "repository": { "repositoryArn": "arn:aws:ecr:us-east-1:111122223333:repository/hello-world", "registryId": "111122223333", "repositoryName": "hello-world", "repositoryUri": "111122223333.dkr.ecr.us-east-1.amazonaws.com/hello-world", "createdAt": "2023-03-09T10:39:01+00:00", "imageTagMutability": "MUTABLE", "imageScanningConfiguration": { "scanOnPush": true }, "encryptionConfiguration": { "encryptionType": "AES256" } } }
  3. Copy the repositoryUri from the output in the previous step.

  4. Run the docker tag command to tag your local image into your Amazon ECR repository as the latest version. In this command:

    • docker-image:test is the name and tag of your Docker image. This is the image name and tag that you specified in the docker build command.

    • Replace <ECRrepositoryUri> with the repositoryUri that you copied. Make sure to include :latest at the end of the URI.

    docker tag docker-image:test <ECRrepositoryUri>:latest

    Example:

    docker tag docker-image:test 111122223333.dkr.ecr.us-east-1.amazonaws.com/hello-world:latest
  5. Run the docker push command to deploy your local image to the Amazon ECR repository. Make sure to include :latest at the end of the repository URI.

    docker push 111122223333.dkr.ecr.us-east-1.amazonaws.com/hello-world:latest
  6. Create an execution role for the function, if you don't already have one. You need the Amazon Resource Name (ARN) of the role in the next step.

  7. Create the Lambda function. For ImageUri, specify the repository URI from earlier. Make sure to include :latest at the end of the URI.

    aws lambda create-function \ --function-name hello-world \ --package-type Image \ --code ImageUri=111122223333.dkr.ecr.us-east-1.amazonaws.com/hello-world:latest \ --role arn:aws:iam::111122223333:role/lambda-ex
    Note

    You can create a function using an image in a different AWS account, as long as the image is in the same Region as the Lambda function. For more information, see Amazon ECR cross-account permissions.

  8. Invoke the function.

    aws lambda invoke --function-name hello-world response.json

    You should see a response like this:

    { "ExecutedVersion": "$LATEST", "StatusCode": 200 }
  9. To see the output of the function, check the response.json file.

To update the function code, you must build the image again, upload the new image to the Amazon ECR repository, and then use the update-function-code command to deploy the image to the Lambda function.

Lambda resolves the image tag to a specific image digest. This means that if you point the image tag that was used to deploy the function to a new image in Amazon ECR, Lambda doesn't automatically update the function to use the new image.

To deploy the new image to the same Lambda function, you must use the update-function-code command, even if the image tag in Amazon ECR remains the same. In the following example, the --publish option creates a new version of the function using the updated container image.

aws lambda update-function-code \ --function-name hello-world \ --image-uri 111122223333.dkr.ecr.us-east-1.amazonaws.com/hello-world:latest \ --publish