Jaeger exporter should be its own go module

[iredelmeier]

Among other things, this would decouple the core code from all the Jaeger dependencies, such as Thrift.

[eran-levy]

@rghetia @iredelmeier will be happy to contribute the new module, can I just reference the new module repo here?

[rghetia]

@eran-levy , yes. Thanks for contributing.

[eran-levy]

@rghetia ok will ref soon, wanted to make sure I document the way to generate the thrift clients that we have under internal/gen-go/jaeger - which jaeger version are we compatible with? when I generated using the Makefile that available at: https://github.com/jaegertracing/jaeger/tree/v1.14.0 I didnt see the same files that we have under our internal/gen-go/jaeger folder, how did you generate them? or you just combined them into the one file?

[rghetia]

@eran-levy I did not generate those files. I had simply ported jaeger exporter from opencensus jaeger exporter v0.1.0.
If jaeger client library is used then gen-go files are not required. See PR#7. Using jaeger client library was discussed in #128.

[eran-levy]

@rghetia ok np, so here is the repo: https://github.com/eran-levy/opentelemtry-go-exporter-jaeger
let me know after you fork this repo into https://github.com/open-telemetry and then I will commit the changes to: https://github.com/open-telemetry/opentelemetry-go

the discussions around the jaeger go client libs are interesting and i agree that we shall have a single strategy re our clients usage. Currently, i will leave it as is with gen-go as you ported.
Obviously will be very happy to contribute to that as well.

[rghetia]

@eran-levy there may be some confusion here. While we have not decided where the exporter would reside, but we want the exporters to be its own module. Similar to examples (example/http, example/basic). Later when we have a place (another repo or different directory within the same repo) we will have another PR to do the change.

[eran-levy]

@rghetia ok, tnx, see PR #237