ROOT_PATH is not respected

[rsmithpivotbio]

Problem description

I'm attempting to run TiTiler behind a reverse proxy, and want to set a root path at /imagery. I attempted to set an environment variable when running the docker container to TITILER_API_ROOT_PATH=/imagery. However, it does not seem to be respected. The urls work as before without the /imagery prefix, but when I add /imagery, it returns 404.

Log output

ubuntu@RSMITH-LAPTO:~/titiler$ docker run --name titiler     -p 8000:8000     --env PORT=8000     --env WORKERS_PER_CORE=1 --env TITILER_API_ROOT_PATH=/imagery     --rm -it ghcr.io/developmentseed/titiler:latest
Checking for script in /app/prestart.sh
Running script /app/prestart.sh
Running inside /app/prestart.sh, you could add migrations to this file, e.g.:

#! /usr/bin/env bash

# Let the DB start
sleep 10;
# Run migrations
alembic upgrade head

{"loglevel": "info", "workers": 8, "bind": "0.0.0.0:8000", "graceful_timeout": 120, "timeout": 120, "keepalive": 5, "errorlog": "-", "accesslog": "-", "workers_per_core": 1.0, "use_max_workers": null, "host": "0.0.0.0", "port": "8000"}
[2023-05-19 14:45:39 +0000] [1] [INFO] Starting gunicorn 20.1.0
[2023-05-19 14:45:39 +0000] [1] [INFO] Listening at: http://0.0.0.0:8000 (1)
[2023-05-19 14:45:39 +0000] [1] [INFO] Using worker: uvicorn.workers.UvicornWorker
[2023-05-19 14:45:39 +0000] [8] [INFO] Booting worker with pid: 8
[2023-05-19 14:45:39 +0000] [9] [INFO] Booting worker with pid: 9
[2023-05-19 14:45:39 +0000] [10] [INFO] Booting worker with pid: 10
[2023-05-19 14:45:39 +0000] [11] [INFO] Booting worker with pid: 11
[2023-05-19 14:45:39 +0000] [12] [INFO] Booting worker with pid: 12
[2023-05-19 14:45:39 +0000] [34] [INFO] Booting worker with pid: 34
[2023-05-19 14:45:39 +0000] [35] [INFO] Booting worker with pid: 35
[2023-05-19 14:45:39 +0000] [36] [INFO] Booting worker with pid: 36
[2023-05-19 14:45:41 +0000] [8] [INFO] Started server process [8]
[2023-05-19 14:45:41 +0000] [8] [INFO] Waiting for application startup.
[2023-05-19 14:45:41 +0000] [8] [INFO] Application startup complete.
[2023-05-19 14:45:41 +0000] [9] [INFO] Started server process [9]
[2023-05-19 14:45:41 +0000] [9] [INFO] Waiting for application startup.
[2023-05-19 14:45:41 +0000] [9] [INFO] Application startup complete.
[2023-05-19 14:45:41 +0000] [11] [INFO] Started server process [11]
[2023-05-19 14:45:41 +0000] [11] [INFO] Waiting for application startup.
[2023-05-19 14:45:41 +0000] [11] [INFO] Application startup complete.
[2023-05-19 14:45:41 +0000] [10] [INFO] Started server process [10]
[2023-05-19 14:45:41 +0000] [10] [INFO] Waiting for application startup.
[2023-05-19 14:45:41 +0000] [10] [INFO] Application startup complete.
[2023-05-19 14:45:41 +0000] [35] [INFO] Started server process [35]
[2023-05-19 14:45:41 +0000] [35] [INFO] Waiting for application startup.
[2023-05-19 14:45:41 +0000] [35] [INFO] Application startup complete.
[2023-05-19 14:45:41 +0000] [34] [INFO] Started server process [34]
[2023-05-19 14:45:41 +0000] [34] [INFO] Waiting for application startup.
[2023-05-19 14:45:41 +0000] [34] [INFO] Application startup complete.
[2023-05-19 14:45:41 +0000] [12] [INFO] Started server process [12]
[2023-05-19 14:45:41 +0000] [12] [INFO] Waiting for application startup.
[2023-05-19 14:45:41 +0000] [12] [INFO] Application startup complete.
[2023-05-19 14:45:42 +0000] [36] [INFO] Started server process [36]
[2023-05-19 14:45:42 +0000] [36] [INFO] Waiting for application startup.
[2023-05-19 14:45:42 +0000] [36] [INFO] Application startup complete.
172.17.0.1:37568 - "GET /stac/info?url=https%3A%2F%2Fcanada-spot-ortho.s3.amazonaws.com%2Fcanada_spot_orthoimages%2Fcanada_spot5_orthoimages%2FS5_2007%2FS5_11055_6057_20070622%2FS5_11055_6057_20070622.json&assets=pan&assets=B1 HTTP/1.1" 200
172.17.0.1:37570 - "GET /imagery/stac/info?url=https%3A%2F%2Fcanada-spot-ortho.s3.amazonaws.com%2Fcanada_spot_orthoimages%2Fcanada_spot5_orthoimages%2FS5_2007%2FS5_11055_6057_20070622%2FS5_11055_6057_20070622.json&assets=pan&assets=B1 HTTP/1.1" 404

[vincentsarago]

Hi @rsmithpivotbio
I've converted this as a discussion first, but will move back to issue if it is really a bug in titiler!

Have you looked at #342 ?

This is quite a common issue with FastAPI/Starlette and I doubt this is titiler specific 🙏

[rsmithpivotbio]

Indeed - looking at the docs, this is not a titiler issue.

For a bit more context, I want to put titiler behind an AWS ALB. ALB does not support stripping the path prefix, so it sends the full path (in my case /imagery/stac/...) to titler/FastAPI. FastAPI mentions the situation here: https://fastapi.tiangolo.com/advanced/behind-a-proxy/#about-proxies-with-a-stripped-path-prefix, but I'm not finding an easy solution. Looks like I may need to go down the route of #342 unless there is a simpler way?

[geospatial-jeff]

You could use a proxy like nginx to strip the prefix. alb > nginx > titiler