README.md

Day 20: Advanced API Development

Overview

This day focuses on Advanced API Development in Go. You will learn how to build advanced REST and GraphQL APIs, implement middleware, and add features like rate limiting and authentication.

Tasks

• Task 1: Build a REST API with advanced features like pagination and filtering.
• Task 2: Implement a GraphQL API using the gqlgen library.
• Task 3: Add middleware for rate limiting and authentication.

Resources

• Go REST API Best Practices
• gqlgen Documentation
• Rate Limiting in Go

Example Code

// Example: Middleware for Rate Limiting
package main

import (
    "fmt"
    "net/http"
    "time"

    "golang.org/x/time/rate"
)

var limiter = rate.NewLimiter(1, 3) // 1 request per second, burst of 3

func rateLimitedHandler(next http.Handler) http.Handler {
    return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
        if !limiter.Allow() {
            http.Error(w, "Too Many Requests", http.StatusTooManyRequests)
            return
        }
        next.ServeHTTP(w, r)
    })
}

func mainHandler(w http.ResponseWriter, r *http.Request) {
    fmt.Fprintln(w, "Welcome to Advanced API Development!")
}

func main() {
    mux := http.NewServeMux()
    mux.Handle("/", rateLimitedHandler(http.HandlerFunc(mainHandler)))

    fmt.Println("Server is running on port 8080")
    http.ListenAndServe(":8080", mux)
}

Exercises

• Build a REST API with advanced features like sorting, filtering, and pagination.
• Create a GraphQL API using gqlgen and define custom resolvers.
• Add middleware for rate limiting and JWT-based authentication to your API.