fix(debugging): ensure dynamic instrumentation enabled [backport 1.18] (#6763)

Backport c98875a from #6618 to 1.18.

With the introduction of exception debugging, the new enablement logic
caused the dynamic instrumentation to not register with the remoteconfig
client when the programmatic API was used, unless
`DD_DYNAMIC_INSTRUMENTATION_ENABLED` is also set. Since this is not the
documented behaviour, we make this fix to align with the expected
behaviour of the programmatic API.

## Checklist

- [x] Change(s) are motivated and described in the PR description.
- [x] Testing strategy is described if automated tests are not included
in the PR.
- [x] Risk is outlined (performance impact, potential for breakage,
maintainability, etc).
- [x] Change is maintainable (easy to change, telemetry, documentation).
- [x] [Library release note
guidelines](https://ddtrace.readthedocs.io/en/stable/releasenotes.html)
are followed. If no release note is required, add label
`changelog/no-changelog`.
- [x] Documentation is included (in-code, generated user docs, [public
corp docs](https://github.com/DataDog/documentation/)).
- [x] Backport labels are set (if
[applicable](https://ddtrace.readthedocs.io/en/latest/contributing.html#backporting))

## Reviewer Checklist

- [x] Title is accurate.
- [x] No unnecessary changes are introduced.
- [x] Description motivates each change.
- [x] Avoids breaking
[API](https://ddtrace.readthedocs.io/en/stable/versioning.html#interfaces)
changes unless absolutely necessary.
- [x] Testing strategy adequately addresses listed risk(s).
- [x] Change is maintainable (easy to change, telemetry, documentation).
- [x] Release note makes sense to a user of the library.
- [x] Reviewer has explicitly acknowledged and discussed the performance
implications of this PR as reported in the benchmarks PR comment.
- [x] Backport labels are set in a manner that is consistent with the
[release branch maintenance
policy](https://ddtrace.readthedocs.io/en/latest/contributing.html#backporting)

Co-authored-by: Gabriele N. Tornetta <[email protected]>
Co-authored-by: Munir Abdinur <[email protected]>

Author: 3 people

ddtrace/debugging/_debugger.py

@@ -186,6 +186,8 @@ def enable(cls, run_module=False):
 
         log.debug("Enabling %s", cls.__name__)
 
+        di_config.enabled = True
+
         cls.__watchdog__.install()
 
         if di_config.metrics:
@@ -215,6 +217,8 @@ def disable(cls, join=True):
 
         log.debug("Disabling %s", cls.__name__)
 
+        remoteconfig_poller.unregister("LIVE_DEBUGGING")
+
         forksafe.unregister(cls._restart)
         atexit.unregister(cls.disable)
         unregister_post_run_module_hook(cls._on_run_module)
@@ -229,6 +233,8 @@ def disable(cls, join=True):
         if di_config.metrics:
             metrics.disable()
 
+        di_config.enabled = False
+
         log.debug("%s disabled", cls.__name__)
 
     def __init__(self, tracer=None):

releasenotes/notes/fix-di-enable-programmatic-api-2dd583ac87af5451.yaml

@@ -0,0 +1,6 @@
+---
+fixes:
+  - |
+    dynamic instrumentation: Fixed the programmatic API to ensure that the
+    dynamic instrumentation service is fully enabled when
+    ``Dynamic Instrumentation.enable()`` is called.

tests/debugging/test_api.py

@@ -1,7 +1,5 @@
 import pytest
 
-from ddtrace.debugging import DynamicInstrumentation
-
 
 @pytest.mark.subprocess(ddtrace_run=True, env=dict(DD_DYNAMIC_INSTRUMENTATION_ENABLED="true"), err=None)
 def test_debugger_enabled_ddtrace_run():
@@ -17,12 +15,20 @@ def test_debugger_disabled_ddtrace_run():
     assert DynamicInstrumentation._instance is None
 
 
+@pytest.mark.subprocess
 def test_debugger_enabled_programmatically():
+    from ddtrace.internal.remoteconfig.worker import remoteconfig_poller
+
+    assert "LIVE_DEBUGGING" not in remoteconfig_poller._client._products
+    from ddtrace.debugging import DynamicInstrumentation
+
     DynamicInstrumentation.enable()
     assert DynamicInstrumentation._instance is not None
+    assert "LIVE_DEBUGGING" in remoteconfig_poller._client._products
 
     DynamicInstrumentation.disable()
     assert DynamicInstrumentation._instance is None
+    assert "LIVE_DEBUGGING" not in remoteconfig_poller._client._products
 
 
 @pytest.mark.subprocess(err=None)