[Win/Linux] add a graalvm native image example

[i10416]

Add an example sbt project that can build dashboard example app into standalone binary with graal vm native image on Windows and Linux.

To add an example, I moved examples/ to examples/dashboard/

• graalvm-ce-java16:21.1.0
• Windows 10 amd64
• ubuntu 20.04 amd64

git clone git@github.com:HumbleUI/JWM
git checkout add-example
cd examples/sbt
sbt nativeImageCommand nativeImageRunAgent
sbt nativeImage

./target/native-image/example

[GavinRay97]

Is the native-image-configs folder meant to be generated by the end user in the demo? Cloned this repo to try on Windows. When building, I get this:

rayga@DESKTOP-88A51E5 MINGW64 ~/Projects/tmp/JWM/examples/sbt (add-example)
$ sbt.bat -Dsbt.log.noformat=true 'show nativeImage'

[info] welcome to sbt 1.5.5 (GraalVM Community Java 16.0.2)
<SNIPPED>

[info] C:\GraalVM\graalvm-ce-java17-21.3.0-dev\bin\native-image.cmd -cp C:\Users\rayga\Projects\tmp\JWM\examples\sbt\target\native-image-internal\manifest.jar -H:ReflectionConfigurationFiles=C:\Users\rayga\Projects\tmp\JWM\examples\sbt\target\native-image-configs\reflect-config.json -H:ConfigurationFileDirectories=C:\Users\rayga\Projects\tmp\JWM\examples\sbt\target\native-image-configs -H:+JNI --no-fallback --report-unsupported-elements-at-runtime --allow-incomplete-classpath io.github.humbleui.jwm.examples.Example C:\Users\rayga\Projects\tmp\JWM\examples\sbt\target\native-image\example
[C:\Users\rayga\Projects\tmp\JWM\examples\sbt\target\native-image\example:18952]    classlist:   4,319.00 ms,  0.96 GB
[C:\Users\rayga\Projects\tmp\JWM\examples\sbt\target\native-image\example:18952]        (cap):   5,956.32 ms,  0.96 GB
[C:\Users\rayga\Projects\tmp\JWM\examples\sbt\target\native-image\example:18952]        setup:   7,286.96 ms,  0.96 GB
Error: The reflection configuration file "C:\Users\rayga\Projects\tmp\JWM\examples\sbt\target\native-image-configs\reflect-config.json" does not exist.
[C:\Users\rayga\Projects\tmp\JWM\examples\sbt\target\native-image\example:18952]      [total]: Error: Use -H:+ReportExceptionStackTraces to print stacktrace of underlying exception
 11,693.93 ms,  0.96 GB
# Printing build artifacts to: C:\Users\rayga\Projects\tmp\JWM\examples\sbt\target\native-image\example.build_artifacts.txt
Error: Image build request failed with exit status 1
[error] native-image command failed with exit code '1'
[error] (nativeImage) native-image command failed with exit code '1'
[error] Total time: 17 s, completed Oct 3, 2021, 12:48:44 PM

[i10416]

Is the native-image-configs folder meant to be generated by the end user in the demo?

@GavinRay97 Yes, those files are generated by sbt nativeImageRunAgent command. Did you run sbt nativeImageRunAgent?

sbt nativeImageRunAgent command generates target/native-image-configs directory and configuration files.

Sorry, you need to run not nativeImage but nativeImageCommand first.

cd examples/sbt
// nativeImageCommand fetches graalvm and native image command.
sbt nativeImageCommand nativeImageRunAgent
sbt nativeImage

Running sbt nativeImage for the first time can fail and this is not problem. This is just for fetching missing graal native agent components.

Then run sbt nativeImageRunAgent and retry sbt nativeImage command, I think it works.

[GavinRay97]

Ahhh okay, yeah this the step I missed -- thanks!

[i10416]

Thank you for trying this! If something still goes wrong, please feel free to ask!

[tonsky]

Thanks for the PR, merged to main.

I renamed examples/sbt to examples/native-image, seems to be better-suited.

One thing though: right now .java in examples/native-image is a copy of .java from examples/dashboard. I would prefer if we shared source files somehow, otherwise they will start drifting at some point. Is it possible with sbt?

[i10416]

@tonsky

Is it possible with sbt?

yes, Iwill send PR soon.