Custom server
Framework uses Uvicorn and serves the app in the root path i.e. /
. If you need to use another ASGI-compatible server or fine-tune Uvicorn, you can easily do so.
Configure webserver
You can tune your server by adding a server_setup.py
file to the root
of your application, next to the main.py
and ui.json
files.
This file is executed before starting writer. It allows you to configure authentication, add your own routes and middlewares on FastAPI.
# server_setup.py
import typing
import writer.serve
if typing.TYPE_CHECKING:
from fastapi import FastAPI
# Returns the FastAPI application associated with the writer server.
asgi_app: FastAPI = writer.serve.app
@asgi_app.get("/probes/healthcheck")
def hello():
return "1"
server_setup.py
is disabled by default on edit mode. If you want to use in edit
mode, you can launch writer edit --enable-server-setup <app>
.
Implement custom server
You can import writer.serve
and use the function get_asgi_app
. This returns an ASGI app created by FastAPI, which you can choose how to serve.
The following code can serve as a starting point. You can save this code as serve.py
and run it with python serve.py
.
import uvicorn
import writer.serve
app_path = "." # . for current working directory
mode = "run" # run or edit
asgi_app = writer.serve.get_asgi_app(app_path, mode)
uvicorn.run(asgi_app,
host="0.0.0.0",
port=5328,
log_level="warning",
ws_max_size=writer.serve.MAX_WEBSOCKET_MESSAGE_SIZE)
Note the inclusion of the imported ws_max_size
setting. This is important for normal functioning of the framework when dealing with bigger files.
Fine-tuning Uvicorn allows you to set up SSL, configure proxy headers, etc, which can prove vital in complex deployments.
If you want to disable server setup hook, you should use enable_server_setup
:
asgi_app = writer.serve.get_asgi_app(app_path, mode, enable_server_setup=False)
Multiple apps at once
Framework is built using relative paths, so it can be served from any path. This allows multiple apps to be simultaneously served on different paths.
The example below uses the get_asgi_app
function to obtain two separate Framework apps, which are then mounted on different paths, /app1
and /app2
, of a FastAPI app.
import uvicorn
import writer.serve
from fastapi import FastAPI, Response
root_asgi_app = FastAPI(lifespan=writer.serve.lifespan)
sub_asgi_app_1 = writer.serve.get_asgi_app("../app1", "run")
sub_asgi_app_2 = writer.serve.get_asgi_app("../app2", "run")
root_asgi_app.mount("/app1", sub_asgi_app_1)
root_asgi_app.mount("/app2", sub_asgi_app_2)
@root_asgi_app.get("/")
async def init():
return Response("""
<h1>Welcome to the App Hub</h1>
""")
uvicorn.run(root_asgi_app,
host="0.0.0.0",
port=5328,
log_level="warning",
ws_max_size=writer.serve.MAX_WEBSOCKET_MESSAGE_SIZE)