perf: Add profiling option for backend routes

It produces a HTML report to better identify slow actions in routes.

.pre-commit-config.yaml

@@ -77,6 +77,7 @@ repos:
           - types-lxml
           - cryptography
           - types-croniter
+          - pyinstrument
   - repo: local
     hooks:
       - id: pylint

backend/capellacollab/__main__.py

@@ -93,6 +93,22 @@ async def shutdown():
 )
 
 
+if config.logging.profiling:
+    import pyinstrument
+
+    @app.middleware("http")
+    async def profile_request(request: fastapi.Request, call_next):
+        profiling = request.query_params.get("profile", False)
+        if profiling:
+            profiler = pyinstrument.Profiler(async_mode="enabled")
+            profiler.start()
+            await call_next(request)
+            profiler.stop()
+            return responses.HTMLResponse(profiler.output_html())
+        else:
+            return await call_next(request)
+
+
 @app.get(
     "/docs", response_class=responses.RedirectResponse, include_in_schema=False
 )

backend/capellacollab/config/models.py

@@ -329,6 +329,10 @@ class LoggingConfig(BaseConfig):
         description="The path to the log file (saved as 'backend.log').",
         examples=["logs/"],
     )
+    profiling: bool = pydantic.Field(
+        default=False,
+        description="Enable profiling of requests.",
+    )
 
 
 class RequestsConfig(BaseConfig):

backend/pyproject.toml

@@ -71,6 +71,7 @@ dev = [
   "aioresponses",
   "types-lxml",
   "types-croniter",
+  "pyinstrument",
 ]
 
 [tool.black]

docs/docs/development/backend/profiling.md

@@ -0,0 +1,38 @@
+<!--
+ ~ SPDX-FileCopyrightText: Copyright DB InfraGO AG and contributors
+ ~ SPDX-License-Identifier: Apache-2.0
+ -->
+
+# Profile Backend Routes
+
+Profiling can be useful if you want to examine the performance of specific
+backend routes.
+
+## Enable profiling
+
+In the `config.yaml`, set the `logging.profiling` key to `True`. Then, call the
+route you want to profile with the `profile` query parameter set to `True`.
+
+For example, to profile the `/api/v1/metadata` route, you would call
+`/api/v1/metadata?profile=True` in the browser. It will return a HTML report.
+
+!!! info
+
+    Synchronous routes are not supported properly. If you want to profile a
+    synchronous route, add `async` to the route definition.
+
+    ```
+    @router.get(...)
+    def metadata():
+        ...
+    ```
+
+    becomes
+
+    ```
+    @router.get(...)
+    async def metadata():
+        ...
+    ```
+
+    [More Information on GitHub](https://github.com/joerick/pyinstrument/issues/257)

docs/mkdocs.yml

@@ -111,6 +111,7 @@ nav:
       - Introduction: development/index.md
       - Backend:
           - Code Style: development/backend/code-style.md
+          - Profiling: development/backend/profiling.md
           - Technology Overview: development/backend/technology.md
           - Extension Modules: development/backend/extensions.md
           - Exception Handling: development/backend/exception.md