Create a layer for the opentelemetry php extension

[iokiwi]

• https://github.com/open-telemetry/opentelemetry-php-instrumentation
• https://opentelemetry.io/docs/instrumentation/php/automatic/

[GrahamCampbell]

How large is the generated layer, btw?

[iokiwi]

How large is the generated layer, btw?

-rw-r--r-- 1 simon simon 11K Nov 19 14:00 layer-opentelemetry-php-80.zip
-rw-r--r-- 1 simon simon 11K Nov 19 14:00 layer-opentelemetry-php-81.zip
-rw-r--r-- 1 simon simon 11K Nov 19 14:00 layer-opentelemetry-php-82.zip

[GrahamCampbell]

I would still keep the make flags, but this is fast to build in any case, so it won't make a lot of difference (if implemented correctly for grpc, it actually does make a big difference there).

[iokiwi]

Aight restored. Yeah I should have checked what they do. Probably wont make a big practical differences as opentelemetry is quick but might as well have them.

Thanks!

[iokiwi]

Hey sorry I added the extension to the readme as well. I don't have merge rights so I'm not sure what the next steps after reviewer approval are.