Feature request: Common request parameters for multiple routes

[OscarVanL]

Is your feature request related to a problem? Please describe.
In my org, we have a common header that is used for internal log correlation between microservices, X-TraceId. This means that every API route should accept this header so it can be propagated accordingly.

I would like this to be included on our generate OpenAPI spec.

However, I cannot find a DRY way to include the same request header on every route.

It would be helpful to be able to define ninja request parameters, such as query args or headers on a router (or even NinjaAPI) level. This would avoid unnecessary repetition.

Describe the solution you'd like
Currently, it is possible to add these request parameters in two ways.

Method 1: Function parameters

@api.get("/ready", tags=["k8s"], response={200: None})
def ready(request, trace_id: str = Header(alias="X-TraceId")):
    return 200, None

Method 2: openapi_extra

@api.get("/ready", tags=["k8s"], response={200: None}, openapi_extra={
    "parameters": [
        {
            "in": "header",
            "name": "X-TraceId",
            "required": False,
            "schema": {"type": "string"},
            "description": "Tracking ID for log correlation"
        }
    ]
})
def ready(request):
    return 200, None

It would be great to be able to define either:

• request method parameters that are automatically "inherited" by all routes in that router
• openapi_extra that are "inherited" by all routes in the router

[OscarVanL]

I figured out one way to achieve this, by subclassing Router and extending the existing openapi_extra kwarg:

class MyRouter(Router):
    def api_operation(self, *args, **kwargs):
        openapi_extra = kwargs.get("openapi_extra") or {}
        params = openapi_extra.setdefault("parameters", [])
        params.append(
            {
                "in": "header",
                "name": "X-TraceId",
                "required": False,
                "schema": {
                    "type": "string",
                    "format": "uuid",
                },
                "description": "Trace ID for log correlation"
            })

        kwargs["openapi_extra"] = openapi_extra
        return super().api_operation(*args, **kwargs)

Then I need to replace all Router usages with MyRouter.

However frustratingly I encountered a separate issue similar as described in separate issue here that makes this solution inappropriate, as setting this value overwrites all my URL parameter values in the API spec :(

It would still be nice if there was a more supported/official way to achieve this.

[OscarVanL]

My above workaround above works now that #1517 is released in v1.5.0, but it'd still be nice to have a more supported / built-in way to define common parameters on a router level.