Running behind a proxy

[tayden]

I'd really like to get TiTiler running on an existing server, and have requests to the root path /titiler passed to the port where the TiTiler docker container is running. However, there's currently no way to specify the root_path parameter in the FastAPI instantiation call and so the app is required to run at the root location. (see FastAPI docs on running behind a proxy)

I'd suggest that titiler is enhanced by allowing users to set the root_path parameter given to the FastAPI instance via an environment variable so that it's dead simple to run the service behind a reverse proxy. It would be straightforward to default that root_path location to "/", so nothing anybody currently has running breaks.

[jaysnm]

Hi
I hope this gets an answer because I have fumbled on same issue for a couple of days without making any mojor progress. Below is what I have tried!

From this issue I wrote my main.py script as follows:

from fastapi import FastAPI

from titiler.application.custom import templates
from titiler.application.routers import cog, mosaic, stac, tms
from titiler.application.version import __version__ as titiler_version

from starlette.requests import Request
from starlette.responses import HTMLResponse

from dotenv import dotenv_values

api_config = dotenv_values()

app = FastAPI(
    title=api_config.get('TILER_TITLE'),
    openapi_url="/api/openapi.json",
    description=api_config.get('TILER_DESC'),
    version=titiler_version,
)
app.include_router(
    cog.router, prefix=f"{api_config.get('TILER_SUB_PATH')}/cog", tags=["Cloud Optimized GeoTIFF"]
)
app.include_router(
    stac.router, prefix=f"{api_config.get('TILER_SUB_PATH')}/stac", tags=["SpatioTemporal Asset Catalog"]
)

app.include_router(
    mosaic.router, prefix=f"{api_config.get('TILER_SUB_PATH')}/mosaicjson", tags=["MosaicJSON"]
)
app.include_router(
    tms.router, prefix=f"{api_config.get('TILER_SUB_PATH')}/tileMatrixSets", tags=["TileMatrixSets"]
)
app.mount(api_config.get('TILER_SUB_PATH'), app)


@app.get(f"{api_config.get('TILER_SUB_PATH')}/healthz", description="Health Check", tags=["Health Check"])
def ping():
    """Health check."""
    return {"ping": "pong!"}


@app.get("/", response_class=HTMLResponse, include_in_schema=False)
def landing(request: Request):
    """TiTiler Landing page"""
    return templates.TemplateResponse(
        name="index.html", context={"request": request}, media_type="text/html",
    )

Where TILER_SUB_PATH denotes proxy sub path I wish to run titiler service.
Simulation on /docs works fine for all endpoints embedding the service on another system fails with

Access to fetch at 'http://domain.xx/titiler/cog/metadata/?url=http://domain.yy/stac/cogeo.tif&max_size=256' from origin 'http://domain.yy' has been blocked by CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource. If an opaque response serves your needs, set the request's mode to 'no-cors' to fetch the resource with CORS disabled.

Even after modifying cors middleware, it didn't work either!

from starlette.middleware.cors import CORSMiddleware
....

# Set all CORS enabled origins
app.add_middleware(
    CORSMiddleware,
    allow_origins=api_config.get('CORS_ORIGIN').split(","),
    allow_credentials=True,
    allow_methods=["GET"],
    allow_headers=["*"],
)
....

[tayden]

Hi @jaysnm, take a look at the root_path parameter you can pass to the FastAPI object https://fastapi.tiangolo.com/advanced/behind-a-proxy/#setting-the-root_path-in-the-fastapi-app

[jaysnm]

Hi @tayden
I have followed the link and your PR #343 but still can't get it working. Appending root_path doesn't change access root url as I can load titiler on /.

While on the browser I have /docs, on the console it's printed that I have accessed /titiler/docs but swagger UI doesn't open because openapi.json cannot be found.

The second output /titiler/titiler was generated when I tried /titler on browser. /titiler/openapi.json was generated when accessing /openapi.json on browser which outputs

[tayden]

If you're running on localhost, this would be the expected behaviour. The root_path parameter just tells helps FastAPI figure out the reverse proxy when you have the app running in production. The reverse proxy (e.g. Nginx or Apache) is responsible for adding the /titiler root_path (or whatever it is that you had set root_path to).

This section of the fastapi docs might be helpful to you https://fastapi.tiangolo.com/advanced/behind-a-proxy/#about-root_path

[lsntdev]

Hello Guys, I think I have the same issue when trying to use an existing nginx config, I tried to integrate it with geonode. Is there any way to do this without the change in the source code like here #95. I asked an help here.

[jaysnm]

Went through the links once more only to realize it was a shortcoming on my end. Thanks a lot.