chore(tracer): improve patching debug logs (backport #3568) (#3602)

This is an automatic backport of pull request #3568 done by [Mergify](https://mergify.com).


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Author: mergify[bot]

ddtrace/_monkey.py

@@ -12,6 +12,7 @@
 from .internal.logger import get_logger
 from .internal.telemetry import telemetry_writer
 from .internal.utils import formats
+from .internal.utils.importlib import require_modules
 from .settings import _config as config
 from .vendor.debtcollector.removals import remove
 
@@ -117,6 +118,15 @@ class ModuleNotFoundException(PatchException):
     pass
 
 
+class IntegrationNotAvailableException(PatchException):
+    """Exception for when an integration is not available.
+
+    Raised when the module required for an integration is not available.
+    """
+
+    pass
+
+
 def _on_import_factory(module, raise_errors=True):
     # type: (str, bool) -> Callable[[Any], None]
     """Factory to create an import hook for the provided module name"""
@@ -223,6 +233,11 @@ def _patch_module(module, raise_errors=True):
         if raise_errors:
             raise
         return False
+    except IntegrationNotAvailableException as e:
+        if raise_errors:
+            raise
+        log.debug("integration %s not enabled (%s)", module, str(e))  # noqa: G200
+        return False
     except Exception:
         if raise_errors:
             raise
@@ -267,8 +282,11 @@ def _attempt_patch_module(module):
             # if patch() is not available in the module, it means
             # that the library is not installed in the environment
             if not hasattr(imported_module, "patch"):
-                raise AttributeError(
-                    "%s.patch is not found. '%s' is not configured for this environment" % (path, module)
+                required_mods = getattr(imported_module, "required_modules", [])
+                with require_modules(required_mods) as not_avail_mods:
+                    pass
+                raise IntegrationNotAvailableException(
+                    "missing required module%s: %s" % ("s" if len(not_avail_mods) > 1 else "", ",".join(not_avail_mods))
                 )
 
             imported_module.patch()

ddtrace/contrib/algoliasearch/__init__.py

@@ -26,7 +26,9 @@
 from ...internal.utils.importlib import require_modules
 
 
-with require_modules(["algoliasearch", "algoliasearch.version"]) as missing_modules:
+required_modules = ["algoliasearch", "algoliasearch.version"]
+
+with require_modules(required_modules) as missing_modules:
     if not missing_modules:
         from .patch import patch
         from .patch import unpatch

releasenotes/notes/patching-debug-logs-ba3fa8407a4db72c.yaml

@@ -0,0 +1,4 @@
+---
+other:
+  - |
+    internal: improve debug logs for tracer patching

tests/integration/test_integration.py

@@ -777,6 +777,25 @@ def test_ddtrace_run_startup_logging_injection(ddtrace_run_python_code_in_subpro
     assert b"ValueError: Formatting field not found in record: 'dd.service'" not in err
 
 
+def test_no_module_debug_log(ddtrace_run_python_code_in_subprocess):
+    env = os.environ.copy()
+    env.update(
+        dict(
+            DD_TRACE_DEBUG="1",
+        )
+    )
+    out, err, _, _ = ddtrace_run_python_code_in_subprocess(
+        """
+import logging
+from ddtrace import patch_all
+logging.basicConfig(level=logging.DEBUG)
+patch_all()
+        """,
+        env=env,
+    )
+    assert b"DEBUG:ddtrace._monkey:integration starlette not enabled (missing required module: starlette)" in err
+
+
 def test_no_warnings():
     env = os.environ.copy()
     # Have to disable sqlite3 as coverage uses it on process shutdown