allow user to pass middleware options

[geospatial-jeff]

Related Issue(s):

• Closes Better middleware injection #435

Description:
The goal of this PR is to make it easier for users to configure middleware passed to the application. Starlette / fastapi expect the middleware class and arguments to that class to be passed separately, the starlette.middleware.Middleware class encapsulates this.

• Reworks middleware injection to allow user to pass arguments to each middleware. This is a breaking change to the type signature of StacApi.middleware instance variable (List[type] -> List[Middleware])
• Adds the StacApi.add_middleware for adding middleware to the underlying fastapi application. This method uses the same business logic as Starlette.add_middleware.

Before

from stac_fastapi.api.app import StacApi
from starlette.middleware.cors import CORSMiddleware

# No way to specify middleware arguments.
api = StacApi(
    middlewares=[CORSMiddleware]
)

After

from stac_fastapi.api.app import StacApi
from starlette.middleware import Middleware
from starlette.middleware.cors import CORSMiddleware

# Create middleware w/ options.
cors_middleware = Middleware(
    CORSMiddleware,
    allow_origins=("*",),
    allow_methods=("POST", "GET",)
)

# Add in StacApi constructor.
api = StacApi(
    middleware=[cors_middleware]
)

# Or add after-the-fact.
api.add_middleware(cors_middleware)

PR Checklist:

• Code is formatted and linted (run pre-commit run --all-files)
• Tests pass (run make test)
• Documentation has been updated to reflect changes, if applicable, and docs build successfully (run make docs)
• Changes are added to the CHANGELOG.

[gadomski]

@geospatial-jeff is this PR still a good change? If so, since it's breaking, we should decide if we want it to go in before or after #450.

[gadomski]

After looking at this again, IMO this is a non-breaking change to the type signature of middlewares, since the contained type of the list was undefined previously, and the default argument made it pretty clear what that type should be. So IMO this would be ok to include in 2.5.

[jonhealy1]

Really nice work here!

[vincentsarago]

Let's hold of til #625 get's merged but this PR is ✅

[pedro-cf]

Greetings @vincentsarago @geospatial-jeff @jonhealy1,

How do I convert this type of middleware definition with these new changes?

@app.middleware("http")
async def add_process_time_header(request: Request, call_next):
    start_time = time.time()
    response = await call_next(request)
    process_time = time.time() - start_time
    response.headers["X-Process-Time"] = str(process_time)
    return response

[vincentsarago]

@pedro-cf using http middleware is deprecated (or at least not encouraged by starlette). you can easily create a pure ASGI middleware like https://github.com/developmentseed/titiler/blob/main/src/titiler/core/titiler/core/middleware.py#L66-L100 which will be easier to use in stac-fastapi