AWS Lambda Java 17 Custom Runtime (DEPRECATED)

This project is no longer required, as AWS Lambda now supports Java 17. I've left it here because others might find it's approach useful for other experimentation.

An AWS Lambda layer to enable Java 17 support

Usage

with CDK

• Download java17layer.zip
• Create a Lambda layer using Code.fromAsset java17layer.zip
• Note you might need to adjust the path for your own project structure

LayerVersion java17layer = new LayerVersion(this, "Java17Layer", LayerVersionProps.builder()
        .layerVersionName("Java17Layer")
        .description("Java 17")
        .compatibleRuntimes(Arrays.asList(Runtime.PROVIDED_AL2))
        .code(Code.fromAsset("java17layer.zip"))
        .build());

• Create a function using the PROVIDED_AL2 runtime.
• Add this layer to your function.

Function exampleWithLayer = new Function(this, "ExampleWithLayer", FunctionProps.builder()
        .functionName("example-with-layer")
        .description("example-with-layer")
        .handler("example.HelloWorld::handleRequest")
        .runtime(Runtime.PROVIDED_AL2)
        .code(Code.fromAsset("../software/ExampleFunction/target/example.jar"))
        .memorySize(512)
        .logRetention(RetentionDays.ONE_WEEK)
        .layers(singletonList(java17layer))
        .build());

Layer Details

Java 17

A custom JRE is created to reduce final file size. Lambda has a 250MB unzipped file size limit.

Dockerfile describes how the JRE is built.

JVM Settings

The following JVM settings are added by default.

--add-opens java.base/java.util=ALL-UNNAMED 
-XX:+TieredCompilation -XX:TieredStopAtLevel=1 
-Xshare:on

Further suggestions welcomed

Java Class Path

aws-lambda-java-runtime-interface-client-1.1.0.jar
aws-lambda-java-core-1.2.1.jar
aws-lambda-java-serialization-1.0.0.jar
$LAMBDA_TASK_ROOT
$LAMBDA_TASK_ROOT/*
$LAMBDA_TASK_ROOT/lib/*

Build the layer zip yourself

Requirements

• Docker

Steps

• Run build-jre.sh to build the minimal Java 17 runtime
• Run make-layer.sh to package the runtime, dependencies and bootstrap as a zip