Helidon GCP

This is a demonstrator application using Helidon that hooks into Google Cloud Operations suite of Logging, Monitoring and Tracing:

• Cloud Logging: Java Util Log Handlers using asynchronous processing,
• Cloud Monitoring: Microprofile Metrics,
• Cloud Tracing: Microprofile Trace via OpenTelemetry API and log message correlation,
• Cloud Error Reporting: all ERROR messages flagged augmented with serviceContext version and name from MANIFEST.MF.

Docker Images

This has 3 types of images:

• vanilla: OpenJDK Java 16 Alpine JRE,
• jlink: Java Platform Module System OpenJDK Java 16 Alpine,
• native: GraalVM statically linked binary off scratch using MUSL libc.

They all have their benefits but also pain-points.

Image	Size	Start	Stop	Notes
helidon:vanilla	236MB	3,735ms	22ms	APKO jre17 image
helidon:jlink	148MB	2,470ms	18ms	APKO JLink image
helidon:native	131MB	204ms	4ms	Build failing

⚠️ Native image does have some issues around flushing final logs (see Limitations) so STOP is artificially fast.

Running Locally

To be able to use the GCP credentials when running locally (via Docker for Desktop or similar):

gcloud auth application-default login
docker run --rm -it `
  -p 8080:8080 `
  -e CLOUDSDK_CONFIG=/gcloud `
  -v $Env:APPDATA/gcloud/:/gcloud:ro `
  -v $pwd/error/:/error:rw `
  helidon-gcp:<tag>

Build via Graal Locally

docker run `
  -v $pwd/:/helidon:rw `
  -v $HOME/.m2/repository/:/root/.m2/repository/:rw `
  -v $Env:APPDATA/gcloud/:/gcloud:ro `
  -p 8080:8080 `
  --entrypoint bash `
  -it `
  --rm `
  helidon/jdk17-graalvm-maven:21.3.0

Limitations

• oracle/graal#3351 Just SegFaults every time. On disabling Tracing, the issue appears to stop.