Logging middleware… let’s talk about each of those two words.
You can think of logging as really fancy printing. When a serious application is running then it generally generates logs.
These logs are useful because when something goes wrong, then it’s important to be able to diagnose the problem. It’s also useful for analysis, if you have a big serious web application and lots of people are accessing it, you might use logs to see what api endpoints get used the most.
Python logging is handled with the logging package. Read more about it here
When an HTTP request arrives at your application, the data in that request goes straight to your view. The view then generates a response that gets turned into an HTTP response and sent back to the client code.
Client code sends http request to flask app
Flask creates a python request object and sends it to the view
View generates HTTP response as a python object
Flask generates an actual HTTP response to send to the client
A middleware is a piece of code that gets to process the request before and after the view. So it looks more like this:
Client code sends http request to flask app
Flask creates a request object object and sends it to the MIDDLEWARE
The middleware does some processing then sends the request to the view
View generates HTTP response as a python object and sends it to the MIDDLEWARE
The middleware can do some more processing before passing the response to Flask
Flask generates an actual HTTP response to send to the client
These resources should help you understand how to implement a middleware:
Your job is to write a middleware from scratch.
Your middleware needs to do the following:
info message for every request. The mssage should look like this: f"[{request_method}] {request_url}". For example: [POST] /computersdebug message for every request. The message should just contain the body of the request send to your app. For example if there is a POST request sent to your app in order to create a new computer in the database, then POSTed data should be logged.The logs should be sent to a file called requuest.log. Please note that it is BAD practice to add log files to your git repo. You should make sure that your log files are gitignored.
The log level of your middleware should be controlled by an environmental variable called DEBUG.
infodebuginfoDon’t worry about testing your middleware for now.