Axum Web Framework for Rust - Full Course Notes

Course Overview

• Sections:
  • Beginner: Hello World, Quick Dev setup, and Static Routing
  • Intermediate: First POST API for login, adding cookies, CRUD operations with a mock model layer
  • Advanced: Custom Middleware, Custom Extractor, Custom Error Handling, and Request Logging
• Environment Setup:
  • Server terminal on the right
  • Quick Dev client terminal on the left
  • Refresh functionality displays request flow and responses

Beginner Section

Hello World Setup

• Use tokio::main for async support
• Add axum to Cargo.toml (ensure latest version)
• Create first router with path /hello using GET method
• Return HTML content "Hello World"
• Setup server with a socket address and bind it

Quick Dev Setup

• Use cargo test for quick development and testing
• Add httpc_test as a dev dependency for convenient HTTP client testing
• Set up watch commands for automatic recompilation on changes

Parameter Handling

• Add query parameters using Axum extractors
• Implement a function to handle parameters and default values

Intermediate Section

Login API

• Set up error handling with custom error module
• Implement a simple login handler with hardcoded credentials
• Use cookies for session management
• Store login tokens in cookies

CRUD Operations

• Implement a mock model layer for managing Ticket entities
• Use Arc and Mutex for storing tickets in memory
• Create, list, and delete tickets with mock data

Advanced Section

Custom Middleware

• Require authentication middleware to check for cookies
• Validate and extract user tokens from requests

Context & Extractors

• Implement custom context extractor to pass user information
• Share user context across routes and handlers

Error Handling

• Define server and client error enums for structured error responses
• Use error mapping to translate server errors into client-friendly formats

Request Logging

• Implement middleware for request logging
• Log each request with unique identifiers for tracing

Final Setup

• Configure main server application with composed routers and middleware
• Test end-to-end functionality from simple requests to full CRUD and login flows

Key Concepts

• Axum Features: Routing, middleware, extractors, error handling
• Rust Features: Async programming with Tokio, error handling via Result, memory safety with ownership and borrowing
• Development Tools: Cargo for Rust management, HTTP testing tools

Conclusion

• Axum provides a robust and flexible framework for building web applications in Rust
• Emphasizes security with careful error handling and request logging
• Encourages component-based architecture with router composition and middleware layers
• Supports a full feature set for building scalable and maintainable web applications