Consider adding a Bill of Materials pom.xml

[sebright2]

See https://maven.apache.org/guides/introduction/introduction-to-dependency-mechanism.html#Importing_Dependencies. The Bill of Materials (BOM) could help users specify a consistent set of dependencies for OpenCensus implementations and exporters.

Gradle issue for managing dependencies with a BOM: https://github.com/gradle/gradle/issues/1162 Gradle plugin: https://github.com/lkishalmi/gradle-bom-plugin Examples: https://github.com/GoogleCloudPlatform/google-cloud-java/tree/master/google-cloud-bom https://github.com/sebhoss/maven-boms

[suztomo]

I want Opencensus BOM too, from the observation in https://github.com/spring-cloud/spring-cloud-gcp/issues/1735, where grpc-core-1.21.0 and opencensus-api-0.15 in transitive dependency.

I expect the BOM includes at least the following Maven artifacts:

• io.opencensus:opencensus-api
• io.opencensus:opencensus-contrib-grpc-metrics
• io.opencensus:opencensus-contrib-grpc-util
• io.opencensus:opencensus-contrib-http-util

Once Opencensus BOM is available:

• Opencensus users can import the BOM to ensure they will have consistent versions among them.
• Opencensus and gRPC teams can declare consistency between certain versions of gRPC BOM (available in Maven Central) and Opencensus BOM.

[saturnism]

BOM should include all modules/artifacts published by the project.