python: improved local development experience for scenarios with a python weblog

docs/execute/binaries.md

@@ -145,7 +145,7 @@ Use one of the four options:
 - Add a `python-load-from-s3` file in `binaries`, with a dd-trace-py commit ID or branch inside, the corresponding wheel will be loaded from S3
 - Clone the dd-trace-py repo inside `binaries`: `cd binaries && git clone https://github.com/DataDog/dd-trace-py.git`
 
-For fast local development (for `PARAMETRIC` and `INTEGRATION_FRAMEWORKS` scenarios):
+For fast local development (for `PARAMETRIC`, `INTEGRATION_FRAMEWORKS`, otel and end-to-end scenarios):
 - **Prerequisites (for most use cases, a one-time setup)**: Make sure the native extensions are built for the Python version being used by the scenario you are running. For example, the `PARAMETRIC` and `INTEGRATION_FRAMEWORKS` scenarios require Python 3.11.14 from the `python:3.11-slim` image.
   - If they are not available (for example, if `ddtrace/internal/_encoding.cpython-311-aarch64-linux-gnu.so` does not exist), you will need to build them.
   - Ensure Docker is running. In `dd-trace-py`, run `scripts/ddtest` to start up a shell which is based off of the `testrunner` image.

utils/_context/containers.py

@@ -1003,6 +1003,17 @@ def configure(self, *, host_log_folder: str, replay: bool):
             except Exception:
                 logger.info("No local dd-trace-js found")
 
+        if library == "python":
+            try:
+                with open("./binaries/python-load-from-local", encoding="utf-8") as f:
+                    path = f.read().strip(" \r\n")
+                    source = os.path.join(str(Path.cwd()), path)
+                    resolved_path = Path(source).resolve()
+                    self.volumes[str(resolved_path)] = {"bind": "/volumes/dd-trace-py", "mode": "ro"}
+                    self.environment["PYTHONPATH"] = f"{resolved_path!s}/ddtrace/bootstrap:/volumes/dd-trace-py"
+            except FileNotFoundError:
+                logger.info("No local dd-trace-py found, do not mount any volume or set any python path")
+
         if library in ("php", "cpp_nginx"):
             self.enable_core_dumps()