Logger Utility

Lila provides a built-in Logger utility for web applications. It writes buffered, thread-safe log files organized in date folders and keeps file handles open instead of opening/closing a file per request.

Basic Logging

Import the Logger anywhere in your application to record info, warnings or errors. Each level writes to its own file inside the date folder.

app.py


from lila.core.logger import Logger

# Standard logging -> app/logs/YYYY-MM-DD/info.log
Logger.info("Application started successfully.")
Logger.warning("Database connection is slow.")   # warning.log

# Errors: passing the exception appends the traceback -> error.log
try:
    1 / 0
except Exception as e:
    Logger.error("A critical error occurred", exception=e)

# Custom log types -> app/logs/YYYY-MM-DD/audit.log
Logger.log("audit", "User modified their profile")

Request Logging

Logger.format_request() builds a compact one-line entry and Logger.log_request() writes it to requests.log. The LoggingMiddleware (enabled with App(logging=True)) calls it for every non-static request and redacts sensitive query keys (token, password, _csrf, ...).

auth.py


from lila.core.logger import Logger
from lila.core.request import Request

async def secure_endpoint(request: Request):
    # Logger.request() is async and returns a safe one-line string (it does not log by itself).
    log_string = await Logger.request(request)
    Logger.info(f"Incoming Request: {log_string}")

    # Or write a full request line manually.
    Logger.log_request(
        client_ip=request.client.host if request.client else "unknown",
        method=request.method,
        path=request.url.path,
        query=request.url.query,
        status_code=200,
        duration_ms=12.4,
        user_agent=request.headers.get("user-agent", ""),
    )

Enable it globally from main.py with App(routes=[...], logging=True). Static assets, /_lila/, /favicon and /health are skipped.

Log Storage and Rotation

Logs are written to LILA_LOG_DIR when set, otherwise to app/logs. Lila organizes them into folders by date (app/logs/YYYY-MM-DD/info.log, error.log, warning.log, requests.log, plus any custom type).

There is no automatic rotation daemon. Call delete_old_logs(days) from a cron job / background task; days=30 is the default and clear_logs() removes everything (also used by the admin panel).

cron.py


from lila.core.logger import delete_old_logs, clear_logs

# Delete date folders older than 15 days (returns how many were removed)
delete_old_logs(days=15)

# Remove every log folder and file
clear_logs()