Demo project to showcase how to build an AWS Lambda using:

• Kotlin
• Gradle
• GraalVM
• Spring Boot 3
• Spring Reactive Web (WebFlux, Netty framework)
• Spring Cloud Function
• OpenMeteo API
• OpenAI API
• Docker & Testcontainers

Articles that were written based in this project:

• Exploring Spring Cloud Function, AI and AWS Lambda: building a native serverless application with Kotlin powered by OpenAI.

The application requires JDK 17 at least on a GraalVM distribution.

$ sdk install java 22.3.r17-grl
$ sdk use java 22.3.r17-grl

./gradlew build

./gradlew bootRun

./gradlew nativeRun

Linux:

sam build

macOS:

AWS Lambda requires native applications to be built in an Amazon Linux compatible OS, so on macOS we need to run the build in a compatible Docker container.

1. Build the Docker image compatible with AWS Linux:

   ./aws-image/build-aws-image.sh

2. Run sam build specifying the Docker image:

   sam build --use-container --build-image tech.aaregall.lab/amazonlinux-graalvm:latest

Define the following environment variables on the deployment host.

export AWS_REGION=...
export OPENAI_API_KEY=...

sam deploy --region $AWS_REGION --parameter-overrides ParameterKey=OpenAiApiKey,ParameterValue=$OPENAI_API_KEY

sam logs -n SpringCloudFunctionLambda --stack-name aws-lambda-spring-cloud-function

sam delete SpringCloudFunctionLambda