Added "root_path" config parameter for FastAPI apps

[markus1978]

…pi app root_path.

Fastapi allows to configure a root_path in cases where the app cannot be served directly at the path root. This is meaningful if you need to serve multiple apps/sites from the same host or have other constraints and need to put optimade "somewhere else". We for example want to mount optimade into another fastapi app (alongside our proprietary API, see fastapi docs), other might need to proxy optimade with a path prefix (see fastapi docs here).

[codecov]

Codecov Report

Merging #634 (ee056f7) into master (e20407d) will increase coverage by 0.00%.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##           master     #634   +/-   ##
=======================================
  Coverage   93.27%   93.27%           
=======================================
  Files          60       60           
  Lines        3256     3257    +1     
=======================================
+ Hits         3037     3038    +1     
  Misses        219      219           

Flag	Coverage Δ
project	93.27% <100.00%> (+<0.01%)	⬆️
validator	66.90% <100.00%> (+0.01%)	⬆️

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Impacted Files	Coverage Δ
optimade/server/main.py	94.23% <ø> (ø)
optimade/server/main_index.py	94.44% <ø> (ø)
optimade/server/config.py	88.23% <100.00%> (+0.17%)	⬆️

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[ml-evs]

Thanks for this @markus1978, looks useful.

[ml-evs]

Suggested change

	"Fastapi root_path app parameter. This can be used to serve the API under a "
	"path prefix behind a proxy or as a sub application of another fastapi app."
	"Sets the FastAPI app `root_path` parameter. This can be used to serve the API under a "
	"path prefix behind a proxy or as a sub-application of another FastAPI app. "
	"See https://fastapi.tiangolo.com/advanced/sub-applications/#technical-details-root_path for details."

[ml-evs]

Could you also add this line in the same place for the index meta-database please?

optimade-python-tools/optimade/server/main_index.py

Lines 38 to 50 in e20407d

	app = FastAPI(
	title="OPTIMADE API - Index meta-database",
	description=(
	f"""The [Open Databases Integration for Materials Design (OPTIMADE) consortium](https://www.optimade.org/) aims to make materials databases interoperational by developing a common REST API.
	This is the "special" index meta-database.
	This specification is generated using [`optimade-python-tools`](https://github.com/Materials-Consortia/optimade-python-tools/tree/v{__version__}) v{__version__}."""
	),
	version=__api_version__,
	docs_url=f"{BASE_URL_PREFIXES['major']}/extensions/docs",
	redoc_url=f"{BASE_URL_PREFIXES['major']}/extensions/redoc",
	openapi_url=f"{BASE_URL_PREFIXES['major']}/extensions/openapi.json",
	)

[markus1978]

Sure. I just pushed the suggested changes.

[ml-evs]

Looks good, thanks @markus1978.