Generate opentelemetry-javaagent "-all" artifact during "assemble"

[trask]

Currently

./gradlew assemble

does not generate the -all artifact.

Should we generate the -all artifact during assemble? (EDIT: based on @anuraaga's feedback below: yes!)

#707 is fixing CONTRIBUTING.md to accurately reflect the current state, but if we make this change then we can simplify CONTRIBUTING.md back to just running assemble in the future.

[anuraaga]

I think we should - I work on this repo and even then every time I do assemble, hrm?, unzip -L, hrm?, oh shadowJar.

[trask]

I tried adding the obvious to the bottom of javaagent.gradle:

assemble.dependsOn lightShadow
assemble.dependsOn shadowJar

and it works great with ./gradlew :javaagent:assemble:

  9180430 Aug 16 22:33 opentelemetry-javaagent-0.8.0-SNAPSHOT.jar
 25247132 Aug 16 22:33 opentelemetry-javaagent-0.8.0-SNAPSHOT-all.jar
   399555 Aug 16 22:33 opentelemetry-javaagent-0.8.0-SNAPSHOT-javadoc.jar
     3730 Aug 16 22:33 opentelemetry-javaagent-0.8.0-SNAPSHOT-sources.jar

[trask]

Ooops, hit comment too soon:

but it doesn't work with ./gradlew assemble:

 9180430 Aug 16 22:36 opentelemetry-javaagent-0.8.0-SNAPSHOT.jar
 9180705 Aug 16 22:36 opentelemetry-javaagent-0.8.0-SNAPSHOT-all.jar
  399555 Aug 16 22:36 opentelemetry-javaagent-0.8.0-SNAPSHOT-javadoc.jar
    3730 Aug 16 22:36 opentelemetry-javaagent-0.8.0-SNAPSHOT-sources.jar

(note size of -all artifact in this case)

[anuraaga]

I think we may be able to use the shadow jar publishing configuration since we publish both unshaded and shaded

https://imperceptiblethoughts.com/shadow/publishing/

[anuraaga]

Oh but guess that's only publish, not assemble. Hmm - what's lightshadow? :)

[trask]

what's lightshadow?

shadow, but without the exporters, therefore light shadow 😄

[anuraaga]

Ah ok - hmm I'd expect problems with the light shadow (no classifier) but surprised to see a problem with the all one.

For replacing a jar with shadow, I always use this pattern to disable the jar task and have it depend on the shadow task (s)
https://github.com/anuraaga/aws-opentelemetry-java-instrumentation/blob/master/otelagent/build.gradle.kts#L65