I had a chance to discover FastAPI, an up-to-date and efficient web framework for constructing APIs with Python 3.7+. It utilizes standard Python type hints. Having a secure login page is crucial for any web application and in this piece, I will demonstrate how to create one using FastAPI.
Getting Started with FastAPI
If you haven’t worked with FastAPI before, let me give you a quick overview. FastAPI is built on top of Starlette, a high-performance ASGI framework, and Pydantic, a data validation and serialization library. It leverages the power of Python type hints to provide automatic request and response validation, making your code more robust and less prone to errors.
FastAPI also offers out-of-the-box support for OAuth2 authentication, which we will utilize to secure our login page.
Setting Up the Login Page
To get started, let’s create a new FastAPI project and install the necessary dependencies:
$ mkdir fastapi-login-page
$ cd fastapi-login-page
$ pip install fastapi[all]
Once we have the project structure in place, we can create a new Python file, let’s call it main.py. In this file, we’ll define our login routes and handlers.
First, let’s import the required modules:
from fastapi import FastAPI
from fastapi import Depends
from fastapi.security import OAuth2PasswordBearer
Next, let’s initialize our FastAPI application:
app = FastAPI()
We’ll be using OAuth2 for authentication, so let’s set up the OAuth2 password bearer:
oauth2_scheme = OAuth2PasswordBearer(tokenUrl="/token")
Handling the Login Request
Now, let’s define the route for the login page:
@app.get("/")
async def login(token: str = Depends(oauth2_scheme)):
return {"token": token}
In this example, we’re using the @app.get decorator to define a GET endpoint for the root path (“/”). We’re also specifying a token parameter that will be extracted from the request header using the oauth2_scheme dependency.
Inside the login function, we simply return a JSON response containing the extracted token.
Securing the Login Page
To secure our login page, we need to add authentication and authorization. FastAPI provides built-in OAuth2 support, so let’s utilize it:
@app.post("/token")
async def login(token: str = Depends(oauth2_scheme)):
if token != "secure_token":
raise HTTPException(status_code=401, detail="Invalid credentials")
return {"token": token}
In this example, we’re using the @app.post decorator to define a POST endpoint for the “/token” path. We’re also specifying a token parameter that will be extracted from the request header using the oauth2_scheme dependency.
Inside the login function, we’re checking if the received token matches our secret token. If it doesn’t, we raise an HTTPException with a status code of 401 (Unauthorized) and a detail message indicating invalid credentials.
Conclusion
In this article, we explored how to create a login page using FastAPI. We learned about the features and benefits of FastAPI and saw how it can be used to build highly secure and performant web applications.
FastAPI’s integration with OAuth2 makes it easy to implement authentication and authorization in our applications. By leveraging type hints and automatic request/response validation, FastAPI reduces the chances of errors and makes our code more maintainable.
Building on the foundation of FastAPI, you can further customize the login page according to your specific application requirements. Whether you’re building a small personal project or a large-scale enterprise application, FastAPI provides the tools and flexibility you need to succeed.
To get started with FastAPI and explore more of its powerful features, I recommend checking out the official documentation and trying out some tutorials. Happy coding!