Code generation fails for SEMCONV 1.19.0

[marcalff]

Using the latest spec 1.19.0 release.

Using build tools 0.17.0

Code generation for semantic conventions misses items in the generated code, leading to build breaks compared to version 1.18.0.

In particular, attributes like http.method got moved to common attributes by:

• Use attribute_group for cross-signal HTTP attributes #3183

However, the code generation tool is not ready for this:

• Improvements for attributes semconv generation build-tools#133

As a result, code generated with spec 1.19.0 + build tool 0.17.0 contains less constant definitions compared to 1.18.0, breaking the build because constants for http.method are missing:

• [SEMANTIC CONVENTIONS] Upgrade to version 1.19.0 opentelemetry-cpp#2017

This is not only blocking for 1.19.0, but will also affect every semantic convention changes done from now on, until the build tools are fixed so that code can be generated again from yaml files.

[lmolkova]

I'm not sure if build-tools#133 is related to the issue, but I'm looking into build-tools fix for code generation.

[lmolkova]

The problem is in #3188 and #3190 which reuse resource attributes in trace semconv and vice versa.

Without these two, java templates work just fine. With them they show a bunch of errors.

I believe Java templates work a bit better because they allow taking attributes from everywhere except resources (--exclude resource/**) and cpp does this: --only span

I created this issue open-telemetry/build-tools#155 and should be able to work on it in a few days.

[lmolkova]

@tsloughter, @marcalff, and everyone else affected, would you mind trying new build-tools version - 0.18.0- with the fix? (thanks for @Oberon00 and @arminru for the help!)

It will be necessary to change the generation script to specify which signals to generate using --only flag. It's also important to point source to the root folder so that referenced attributes are resolved everywhere

Here's the sample of changes in Java repo:

docker run --rm \
  -v ${SCRIPT_DIR}/opentelemetry-specification/semantic_conventions:/source \
  -v ${SCRIPT_DIR}/templates:/templates \
  -v ${ROOT_DIR}/semconv/src/main/java/io/opentelemetry/semconv/trace/attributes/:/output \
  otel/semconvgen:$GENERATOR_VERSION \
-  --exclude resource/** \
+  --only span,event,attribute_group,scope \
  -f /source code \
 ...

Resources:

docker run --rm \
- -v ${SCRIPT_DIR}/opentelemetry-specification/semantic_conventions/resource/:/source \
+ -v ${SCRIPT_DIR}/opentelemetry-specification/semantic_conventions:/source \
  -v ${SCRIPT_DIR}/templates:/templates \
  -v ${ROOT_DIR}/semconv/src/main/java/io/opentelemetry/semconv/resource/attributes/:/output \
  semconvgen:$GENERATOR_VERSION \
+ --only resource \
  -f /source code \
....

[tsloughter]

Hm, I'm getting gen-semconv: error: unrecognized arguments: --only resource with 0.18.0

[tsloughter]

Hm, it works if its the first argument.

[Oberon00]

Yes, this is a bit of a quirk of Python's argparse: --only is an argument to the program itself, not to the code (or markdown) subcommand, so you need to specify it before the subcommand (similar to how you need to specify the -v to docker before the image name).
(There would actually be a workaround we could implement in the generator tool: we could add all the common arguments https://github.com/open-telemetry/build-tools/blob/2e9bfeebd327d14a5c5c3daece9b48f756b78cb7/semantic-conventions/src/opentelemetry/semconv/main.py#L223-L257 additionally to all subcommands; however that also makes the --help output weird then)

[marcalff]

@tsloughter, @marcalff, and everyone else affected, would you mind trying new build-tools version - 0.18.0- with the fix? (thanks for @Oberon00 and @arminru for the help!)

Thanks for the fix.

It works, see C++ PR:

• [SEMANTIC CONVENTIONS] Upgrade to version 1.19.0 opentelemetry-cpp#2017