Replace usage of pkg_resources (setuptools) with importlib(._)resources? #2927
Description
Is your feature request related to a problem?
Importing opentelemetry is rather slow due to the import of pkg_resources in opentelemetry.context here
It is a known shortcoming of pkg_resources that at import time it will pass all installed packages which is potentially slow.
In my use case it adds ~0.7 s to the import time.
For this reason setuptools actively discourages the use of pkg_resources See here
Describe the solution you'd like
Replace the use of pkg_resources with importlib.metadata / importlib.resources which is part of the python standard library in newer versions of python and use their backports in importlib_metadata / importlib_resources as needed for older python versions.
In this particular use case pkg_resources is used to find entry points and that should be replaceable by doing
from importlib_metadata import entry_points
...
(entry_point,) = entry_points(group="opentelemetry_context", name=configured_context)
_RUNTIME_CONTEXT = entry_point.load()
Describe alternatives you've considered
- Keep the current state. Using code that is slow and discouraged by its owners.
Additional context
This will also mean that opentelemetry can potentially drop the need for a runtime dependency on setuptools and when older python versions (<3.9) are dropped only use the std library for entry point selection.