Migrate all codegen to weaver

[jsuereth]

• Document how to do codgen (see https://github.com/open-telemetry/weaver/blob/main/crates/weaver_forge/README.md)
• We want a mechanism to not force folks to write JQ (see Define SemConv predefined JQ functions #246, release v0.7.0)
• Migrate Languages (from https://opentelemetry.io/docs/languages/)
  • Migrate C++ - [SEMANTIC CONVENTIONS] Migration to weaver opentelemetry-cpp#3105
  • Migrate .NET (@joaopgrassi) - Migrate semantic conventions generation to Weaver opentelemetry-dotnet-contrib#1944
  • Migrate Erlang/Elixir (@bryannaegele) - Sem con 1.27.0 opentelemetry-erlang#733
  • Migrate Go (@trisch-me) - Go maintainers want to do it themselves
    • Prototype: Migrate semconv codegen to weaver opentelemetry-go#5793
    • Final(?) PR: Weaver opentelemetry-go#5898
  • Migrate Python (@lmolkova) - Switch to weaver to generate semantic conventions opentelemetry-python#4091
  • Migrate Java (@jsuereth) - Use weaver for semantic convention codegen semantic-conventions-java#70
  • Migrate JavaScript / Typescript (@MSNev) - Use weaver to generate latest semconv 1.27 opentelemetry-js#4690
  • Migrate Ruby - semconv 1.25: update in a non-breaking way opentelemetry-ruby#1651
    • Source
    • Contributor @ahayworth
  • Migrate Rust (@lquerel) - Use weaver for semantic convention codegen opentelemetry-rust#2098
  • Migrate PHP (@brettmc ?) - Migrate semantic conventions code generation to weaver opentelemetry-php#1396
  • Migrate Swift - Migrate codegen to weaver opentelemetry-swift#598
    • Source
    • Contributor @Sherlouk
  • Scour for other SIG usage (@jsuereth)
• Collector metadatagen (@jsuereth)
  • Prototype in the works Migrate collector semconv codegen to weaver opentelemetry-collector#11064

[joaopgrassi]

For reference, .NET semconv "package" is here: https://github.com/open-telemetry/opentelemetry-dotnet-contrib/tree/main/src/OpenTelemetry.SemanticConventions

[trisch-me]

for the golang - https://github.com/open-telemetry/opentelemetry-go-build-tools/tree/main/semconvgen

[trentm]

For Node.js/JS/TS open-telemetry/opentelemetry-js#4690 will be migrating semconv codegen to use weaver.

[brettmc]

PHP migration completed and can be checked off...

[marcalff]

@open-telemetry/weaver-maintainers

Please take a look at the opentelemetry-cpp migration to weaver:

• [SEMANTIC CONVENTIONS] Migration to weaver opentelemetry-cpp#3105

Looking for any feedback or suggestions on the weaver / jinja code in particular.

[lquerel]

@marcalff

Looking for any feedback or suggestions on the weaver / jinja code in particular.

Very nice use of Weaver.

On your side, do you see any areas for improvement in Weaver that would make things easier for you?

[marcalff]

@marcalff

Looking for any feedback or suggestions on the weaver / jinja code in particular.

Very nice use of Weaver.

On your side, do you see any areas for improvement in Weaver that would make things easier for you?

Yes, I have a few suggestions.

When a developer find a weaver.yaml file, of a jinja file, and sees it the first time,
it gets extremely challenging to know what to do about it, if a change even minor is required in the file.

If I find a C++ or java file, I know where to find doc about the C++ or java library, language syntax, etc.

If I find weaver.yaml, I can only stare at the content and be stuck.

Do not assume people will know of, or even have heard of, weaver and jinja, and even less that they will know where to find doc about it.

This is why I added systematically pointers to the DOC, in comments, in these files, for opentelemetry-cpp.

I think it will be beneficial to add that in the examples and templates.

By pointers to the doc, I mean something like this:

{#
  Copyright The OpenTelemetry Authors
  SPDX-License-Identifier: Apache-2.0
  This file is:
  - a Jinja template,
  - used to generate semantic conventions,
  - using weaver.
  For doc on the template syntax:
  https://jinja.palletsprojects.com/en/3.0.x/
  For doc on the semantic conventions:
  https://github.com/open-telemetry/semantic-conventions
  For doc on weaver:
  https://github.com/open-telemetry/weaver
#}```

[marcalff]

Also, systematically adding a comment in the generated code, to indicate:

• that it is generated code
• where it is generated from

should be strongly suggested as a best practice, in the jinja templates.

Not all SIG are doing this, from what I could find.

[lquerel]

Created these 2 GH issues:

• Enhance the discoverability of the documentation for Weaver, Jinja, and Semantic Conventions #439
• Add Comment in Generated Code Indicating Source and Generated Status as Best Practice in Jinja Templates #440