Basic FastAPI app template with Jinja2 templating and static files

app.py

"""Template for a minimal FastAPI app serving just one page from a Jinja2 template and a favicon.

Place the Jinja2 "index.html" template in "templates/jinja2" and a "favicon.ico" icon file in
"static/img" and additional static files (JavaScript, CSS, images) below "static". You can then
reference them in the template like this ("path" is relative to "static"):

    {{ url_for('static', path='/dir/file.txt') }}

"""

from contextlib import asynccontextmanager

from fastapi import FastAPI, Request, status
from fastapi.middleware.gzip import GZipMiddleware
from fastapi.responses import HTMLResponse, RedirectResponse
from fastapi.staticfiles import StaticFiles
from fastapi.templating import Jinja2Templates


app = FastAPI()
app.mount("/static", StaticFiles(directory="static"), name="static")
app.add_middleware(GZipMiddleware, minimum_size=1000)

templates = Jinja2Templates(directory="templates/jinja2")


@asynccontextmanager
async def lifespan(app: FastAPI):
    print("Initialising app...")
    yield
    print("shutting down app...")


app.router.lifespan_context = lifespan


@app.get("/", response_class=HTMLResponse)
async def index(req: Request):
    return templates.TemplateResponse(request=req, name="index.html")


@app.get("/favicon.ico")
async def favicon(req: Request):
    return RedirectResponse(
        req.url_for("static", path="/img/favicon.ico"),
        status_code=status.HTTP_301_MOVED_PERMANENTLY,
    )