steps to create the layer zip yourself

Author: msailes

README.md

@@ -34,13 +34,15 @@ Function exampleWithLayer = new Function(this, "ExampleWithLayer", FunctionProps
         .build());
 ```
 
-## Java 17 
+## Layer Details
+
+### Java 17 
 
 A custom JRE is created to reduce final file size. Lambda has a 250MB unzipped file size limit.
 
 [Dockerfile](Dockerfile) describes how the JRE is built.
 
-## JVM Settings
+### JVM Settings
 
 The following JVM settings are added by default.
 
@@ -52,7 +54,7 @@ The following JVM settings are added by default.
 
 Further suggestions welcomed
 
-## Java Class Path
+### Java Class Path
 
 ```
 aws-lambda-java-runtime-interface-client-1.1.0.jar
@@ -62,3 +64,15 @@ $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
+

build-jre.sh

@@ -1,2 +1,2 @@
-docker build --progress=plain -t graalvm-al2-slim .
-docker run -v $(pwd)/layer:/tmp -it graalvm-al2-slim sh -c "cp /opt/jre-17-slim.zip /tmp"
+docker build --progress=plain -t jre17-al2-slim .
+docker run -v $(pwd)/layer:/tmp -it jre17-al2-slim sh -c "cp /opt/jre-17-slim.zip /tmp"

make-layer.sh

@@ -3,8 +3,8 @@
 # -4 IPv4 only
 # -L follow redirect if the server responds with a redirect
 
-curl -4 -L https://repo.maven.apache.org/maven2/com/amazonaws/aws-lambda-java-runtime-interface-client/1.1.0/aws-lambda-java-runtime-interface-client-1.1.0.jar -o aws-lambda-java-runtime-interface-client-1.1.0.jar
-curl -4 -L https://repo.maven.apache.org/maven2/com/amazonaws/aws-lambda-java-core/1.2.1/aws-lambda-java-core-1.2.1.jar -o aws-lambda-java-core-1.2.1.jar
-curl -4 -L https://repo.maven.apache.org/maven2/com/amazonaws/aws-lambda-java-serialization/1.0.0/aws-lambda-java-serialization-1.0.0.jar -o aws-lambda-java-serialization-1.0.0.jar
+curl -4 -L https://repo.maven.apache.org/maven2/com/amazonaws/aws-lambda-java-runtime-interface-client/1.1.0/aws-lambda-java-runtime-interface-client-1.1.0.jar -o layer/aws-lambda-java-runtime-interface-client-1.1.0.jar
+curl -4 -L https://repo.maven.apache.org/maven2/com/amazonaws/aws-lambda-java-core/1.2.1/aws-lambda-java-core-1.2.1.jar -o layer/aws-lambda-java-core-1.2.1.jar
+curl -4 -L https://repo.maven.apache.org/maven2/com/amazonaws/aws-lambda-java-serialization/1.0.0/aws-lambda-java-serialization-1.0.0.jar -o layer/aws-lambda-java-serialization-1.0.0.jar
 
-chmod 755 bootstrap && zip -r java17layer.zip jre17-slim bootstrap 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
+chmod 755 bootstrap && zip -r java17layer.zip jre17-slim bootstrap layer/aws-lambda-java-runtime-interface-client-1.1.0.jar layer/aws-lambda-java-core-1.2.1.jar layer/aws-lambda-java-serialization-1.0.0.jar