This project demonstrates how to run a Kotlin serverless function on AWS lambda using GraalVM It takes advantage of the custom lambda runtime to be able to use GraalVM to run the function. This avoids the increased latency on cold startup.

For more information read the post belonging to this repo - https://medium.com/@mathiasdpunkt/fighting-cold-startup-issues-for-your-kotlin-lambda-with-graalvm-39d19b297730

Run the package.sh to create a deployable zip file. This script does the following:

• build a fat jar of the application
• use the oracle/graalvm-ce docker image to build a native image
• package the native image together with the runtime/bootstrap script into build/package/bundle.zip

We are using the serverless framework to deploy the function.

So to package and deploy run:

npm install
./package.sh
npx serverless deploy

To call the endpoint run:

curl  https://<your-api-id-here>.execute-api.eu-central-1.amazonaws.com/dev/greet/some

After calling the function we can look at the logs to get information about the execution time.

npx serverless logs -f hello
#REPORT RequestId: 155aa77e-6f07-4f31-a468-6de06edfd98b  Duration: 23.85 ms      Billed Duration: 300 ms Memory Size: 1024 MB    Max Memory Used: 66 MB  Init Duration: 178.22 ms