Helidon Graal Native Image POC

Prepare environment

General prerequisites:

1. Maven
2. Java 8
3. Docker

To build the local native image:

1. Install Graal VM - download a release from https://github.com/oracle/graal/releases or from https://www.graalvm.org/downloads/

2. Update the pom.xml - configure native.image property to point to the native-image executable

3. Update the pom.xml - configure version.graalvm property to the version downloaded

   Helidon has its own integration module for Graal VM helidon-graal-native-image-extension make sure the versions of Graal VM are compatible

Build the application

Java jar

Run mvn clean package to build the application to a java jar.

Run mvn exec:exec to run the jar built in previous step

Local native image

Local native image can be built on Linux and MacOs environments.

Run mvn exec:exec@build-native-image to build the native image

See native.image, native.name, native.resources and main.class configuration in pom.xml

See exec plugin configuration execution with id build-native-image for details about invoking the native-image build

Run mvn exec:exec@run-native-image to run the native image

The native image can also be executed from command line (if the native.name property is unchanged): ./target/helidon-example-native-image

Linux native image in Docker

Run mvn clean package -P native-image-docker to build a Linux docker image.

Run docker run -d --name helidon-native -p 8099:8099 helidon/example-graal:1.0.0-SNAPSHOT to run the Docker container based on the image

See configuration of docker plugin in profile native-image-docker in pom.xml

Endpoints

Endpoint	Expected Output	Description
http://localhost:8099	Hello from YAML configuration	Default endpoint that reads message from yaml file
http://localhost:8099/hello	Hello World	Protected endpoint, requires admin role (user jack/jackIsGreat)
http://localhost:8099/json	{"key":"value","time":currentTime,"parameter":"default"}	JSON-P endpoint, requires user role (user jill/jillToo, or jack)
http://localhost:8099/json?param=v	{"key":"value","time":currentTime,"parameter":"v"}	JSON-P endpoint using parameter from requeset
http://localhost:8099/jsonb	{"key":"value","parameter":"default","time":currentTime}	JSON-B endpoint
http://localhost:8099/metrics	Prometheus format metrics	Metrics endpoint providing prometheus data, has /application, /base and /vendor subpaths
http://localhost:8099/health	{"outcome":"UP","checks":[{"name":"test","state":"UP","data":{"time":currentTime}}]}	Health check endpoint providing JSON data in Microprofile format

The JSON-P and JSON-B endpoints also support PUT requests that echo the sent data:

JSON-B: curl -i -X PUT -d '{"time":49, "key":"aValue", "parameter":"theParam"}' http://localhost:8099/jsonb

JSON-P: curl -i -u jack:jackIsGreat -X PUT -d '{"time":49, "key":"aValue", "parameter":"theParam"}' http://localhost:8099/json