Python FastAPI/Uvicorn - 外部记录器无法工作？

Question

I am using logtail.com and for some reason it wont log ONLY in my FastAPI/UVICORN app, I tried using the package in an a different test python file and it worked? I dont understand what I am missing. I call the logger and it should work but it does not, additionally I even do a log INSTANTLY after I instantiate the logger and it does not work. Code below.

#
# Logger.py
#

from logtail import LogtailHandler
import logging

class Logger:
    def __init__(self):
        handler = LogtailHandler(source_token="XXXXXXX")
        logger = logging.getLogger(__name__)
        logger.handlers = []
        logger.setLevel(logging.DEBUG) # Set minimal log level
        logger.addHandler(handler) # asign handler to logger
        logger.debug('I am using Logtail!')

    def info(self, message):
        self.log.info(message)
        
    def error(self, message):
        self.log.error(message)
    
    def debug(self, message):
        self.log.debug(message)
        
    def warning(self, message):
        self.log.warning(message)
        
    def critical(self, message):
        self.log.critical(message)
        
    def exception(self, message):
        self.log.exception(message)

#
# __init__ 
#

from fastapi import FastAPI
from fastapi.middleware.cors import CORSMiddleware

from abe.routes import main, bc_handler

app = FastAPI(title="ABE-Backend", openapi_url="/openapi.json")
app.include_router(main.router)
app.include_router(bc_handler.router)

from abe.utils.logger import Logger

logger = Logger()

#create tables
# models.Base.metadata.create_all(bind=engine)

origins = [
    
]

app.add_middleware(
    CORSMiddleware,
    allow_origins=origins,
    allow_credentials=True,
    allow_methods=["*"],
    allow_headers=["*"],
)

if __name__ == "__main__":
    # Use this for debugging purposes only
    import uvicorn
    uvicorn.run(app, host="0.0.0.0", port=8000, log_level="debug")
    logger.info("Starting server on port 8000, with cors origins: "+str(origins))

Answer 1

It should work, but only after you shutdown the API.

Logging inside the main function before calling uvicorn.run() and inside endpoint routes should work as you expected.

uvicorn.run() is a sync function. So the interpreter waits until the function has finished (API has shutdown) and executes the following statements afterwards.