Azure WebApp LogStream shows the same log multiple times and displays all logs as [ERROR], even though they are [INFO] level

Question

Azure WebApp LogStream shows the same log multiple times and displays all logs as [ERROR], even though they are [INFO] level. Following image shows the actual screenshot of the logstream. Logs

Following python code shows the logger.py implementation. `

import logging
import os
import uuid
from opencensus.ext.azure.log_exporter import AzureLogHandler

class CustomFormatter(logging.Formatter):
    def __init__(self, fmt=None, datefmt=None, style='%', custom_value=''):
        super().__init__(fmt, datefmt, style)
        self.custom_value = custom_value

    def format(self, record):
        # Add the custom value to the log record
        record.custom_value = self.custom_value
        # Call the original format method
        return super().format(record)

def set_logger():
    logger_id = str(uuid.uuid4())
    logging.basicConfig(level=logging.INFO)
    format_str = 'log_id: %(custom_value)s - %(asctime)s - %(name)s - %(levelname)s - %(message)s'
    handler = logging.StreamHandler()
    custom_formatter = CustomFormatter(fmt=format_str, custom_value=logger_id)
    handler.setFormatter(custom_formatter)
    logger = logging.getLogger(__name__)
    logger.setLevel(logging.INFO)
    logger.addHandler(AzureLogHandler(connection_string=os.environ["LOG_CONNECTION_STRING"]))
    logger.addHandler(handler)
    return logger

`

I need to display unique logs without repetitions and ensure that INFO logs are shown as INFO, ERROR logs as ERROR, and so on.

Answer 1

I created a sample Fast API project with Azure logging, successfully deployed it to Azure App service and displayed logs without any issues.

I installed the below packages in my project

pip install fastapi uvicorn
pip install opencensus-ext-azure

This is my project structure:

Fastapilogging/
├── venv/
├── logger.py
├── main.py
├── .env
└── requirements.txt

set up virtual environment

python -m venv venv
venv\Scripts\activate

Logger .py:

import  logging
import  os
import  uuid
from  opencensus.ext.azure.log_exporter  import  AzureLogHandler
class  CustomFormatter(logging.Formatter):
def  __init__(self, fmt=None, datefmt=None, style='%', custom_value=''):
super().__init__(fmt, datefmt, style)
self.custom_value  =  custom_value
def  format(self, record):
record.custom_value =  self.custom_value
return  super().format(record)
def  set_logger():
logger_id  =  str(uuid.uuid4())
logging.basicConfig(level=logging.INFO)
format_str  =  'log_id: %(custom_value)s - %(asctime)s - %(name)s - %(levelname)s - %(message)s'
handler  =  logging.StreamHandler()
custom_formatter  =  CustomFormatter(fmt=format_str, custom_value=logger_id)
handler.setFormatter(custom_formatter)
logger  =  logging.getLogger(__name__)
logger.setLevel(logging.INFO)
connection_string  =  os.getenv("LOG_CONNECTION_STRING")
if  connection_string:
logger.addHandler(AzureLogHandler(connection_string=connection_string))
logger.addHandler(handler)
return  logger

Add connection string in your .env file .env:

LOG_CONNECTION_STRING=your_azure_connection_string_here

And run this command

pip install python-dotenv

I've added load_dotenv() to main .py so that it will load environment variable from .env

main .py:

from  fastapi  import  FastAPI
from  logger  import  set_logger
from  dotenv  import  load_dotenv
import  os
load_dotenv()
app  =  FastAPI()
logger  =  set_logger()
@app.get("/")
def  read_root():
logger.info("Info level log: Hello, world!")
logger.error("Error level log: Something went wrong!")
return {"message": "Hello, World"}
@app.get("/items/{item_id}")
def  read_item(item_id: int, q: str  =  None):
logger.info(f"Fetching item {item_id} with query {q}")
return {"item_id": item_id, "q": q}

Local output:

Before deploying the app to Azure App Service, run the following command in the project's root directory

pip freeze > requirements.txt

This will generate a requirements.txt file with all the dependencies needed for your project.

set the environment variable WEBSITE_RUN_FROM_PACKAGE to 1 in your azure app service.

Add the below startup command in the Configuration section of the web app.

uvicorn main:app --host 0.0.0.0 --port 8000

Output after deployment:

Log stream: