Release v1.42.0

Backend Changes

⛔ Breaking Changes

• HotROD 🚗 application is switched from Jaeger SDK to OpenTelemetry SDK (@yurishkuro in #4187). Some environment variables previously accepted are no longer recognized. See PR for details.
  • Read the blog post
  • Map old env vars from Jaeger SDK to OTel SDK vars (@yurishkuro in #4200)
  • Use patched version of github.com/opentracing-contrib/go-grpc in HotROD (@yurishkuro in #4210)
• tracegen utility is switched from Jaeger SDK to OpenTelemetry SDK (@yurishkuro in #4189). Some environment variables previously accepted are no longer recognized. See PR for details.

New Features

• Add CLI flags for controlling HTTP server timeouts (@yurishkuro in #4167)
• Watch directories for certificate hot-reload (@tsaarni in #4159)
• Support tenant header propagation in query service and grpc-plugin (@pavolloffay in #4151)

Bug fixes, Minor Improvements

• Replace Thrift-gen with Proto-gen types for sampling strategies (@yurishkuro in #4181)
• Use Protobuf-based JSON output for sampling strategies (@yurishkuro in #4173)
• [tests]: Use t.Setenv to set env vars in tests (@Juneezee in #4169)
• ci(lint): bump golangci-lint to v1.50.1 (@mmorel-35 in #4195)
• Convert token propagation integration test to plain unit test (@yurishkuro in #4162)
• Refactor scripts/es-integration-test.sh (@yurishkuro in #4161)
• Fix "index out of range" when receiving a dual client/server Zipkin span (@yurishkuro in #4160)

UI Changes

• No changes.