feat: export package version

[alexander-fenster]

Since we are entering a phase when different client libraries will use different gRPC implementations (most will be migrated to @grpc/grpc-js but some will still stay with grpc), we'd like to have an easy way for the client library to set the gRPC version in the headers without actually knowing if the grpc instance they work with is a C-core or JS implementation.

Can we have this grpc.version added to both implementations to make this tracking easier? (or feel free to suggest another options!)

[murgatroid99]

First, both libraries put some variant of this information in the user-agent header, or at least they're supposed to. Does that resolve your problem of wanting that information in a header?

Second, library users can already do require('grpc/package.json') or require('@grpc/grpc-js/package.json') and then format the information from that however they want.

[alexander-fenster]

Libraries use grpc/${version} header. @JustinBeckwith can know more about tracking and if user-agent header is sufficient. Justin, do you know if can we go with user-agent and not set grpc at all?

As for the second item, it won't be possible since the gax code can accept any grpc instance from the caller and it does not know if it's one or another implementation.

[murgatroid99]

If the current user-agent behavior does not solve your problem, this change needs to go through our API design review process because it is a (non-breaking) API change.

[murgatroid99]

I don't think it's a good idea to export this information pre-formatted for a specific use-case. I would prefer to either export the whole package.json as a single object or export name and version verbatim.

[alexander-fenster]

I'm totally fine with either of those options - I just wanted to have the conversation started :)