ModuleWatchdog is installed unconditionally when ddtrace is imported

[millerdev]

Summary of problem

ModuleWatchdog is installed unconditionally on import.

dd-trace-py/ddtrace/__init__.py

Line 8 in 2107e4c

ModuleWatchdog.install()

This clutters stack traces with many extra lines and generally makes debugging unrelated things more difficult. It would be nice to have a way to disable that with the environment variable DD_TRACE_ENABLED=false.

It would also be nice if DD_TRACE_ENABLED was a master kill switch for all things that get installed automatically on import. For example, currently it looks like DD_INSTRUMENTATION_TELEMETRY_ENABLED is a separate switch that does not respect DD_TRACE_ENABLED=false.

How can we reproduce your problem?

• Set environment variable DD_TRACE_ENABLED=false
• Import ddtrace in a Python shell (see below)
• ModuleWatchdog and other things (instrumentation telemetry, etc.) should not be installed automatically on import. ModuleWatchdog installation can be checked by looking at the type of sys.modules:

$ export DD_TRACE_ENABLED=false
$ python
>>> import sys
>>> type(sys.modules)
<class 'dict'>
>>> import ddtrace
>>> type(sys.modules)
<class 'ddtrace.internal.module.ModuleWatchdog'>
# expected <class 'dict'>

[emmettbutler]

Thanks for this, @millerdev. Sounds like a useful bit of functionality to add. We'll add this to our backlog.