Roadmap for Go API Development

[hardikm9850]

Intermediate Level

1. Data Validation and Error Handling

• Implement proper data validation for incoming requests.
• Learn to handle and return appropriate error responses.
• Explore the validator package for struct validation.

2. Routing and Middleware

• Understand how to set up more complex routes.
• Implement middleware for logging, authentication, rate limiting, etc.
• Explore frameworks like gorilla/mux or echo.

3. Database Integration

• Learn to connect your API to a database (e.g., PostgreSQL, MySQL).
• Explore ORMs like GORM or sqlx.
• Implement CRUD operations and understand query optimization.

4. Authentication and Authorization

• Implement authentication using JWT (JSON Web Tokens).
• Set up role-based access control (RBAC).
• Explore libraries like jwt-go.

Advanced Level

5. Testing

• Write unit tests for your handlers and services.
• Explore testing frameworks like testing, testify, and httptest.
• Learn about mocking dependencies.

6. Concurrency and Goroutines

• Understand the Go concurrency model.
• Implement concurrent request handling.
• Use channels and sync mechanisms to manage concurrency.

7. Performance Optimization

• Learn about profiling and benchmarking.
• Implement caching strategies.
• Use tools like pprof for performance analysis.

8. API Documentation

• Generate and maintain API documentation.
• Explore tools like Swagger and go-swagger.

9. Deploying and Scaling

• Learn about containerization with Docker.
• Explore deployment options like Kubernetes or cloud services (AWS, GCP).
• Implement CI/CD pipelines for automated deployments.

[hardikm9850]

2. B

Middleware

Middleware is a fundamental concept in Go web development, allowing developers to manage and manipulate HTTP requests and responses in a centralized and reusable manner. Here's a look at some commonly used middleware in Go, particularly focusing on popular frameworks like Echo, Chi, and Gorilla Mux.

Commonly Used Middleware

1. Logger Middleware

   • Logs information about each HTTP request, such as the request method, URL, status code, and response time.
   • Useful for debugging and monitoring.

   import "github.com/go-chi/chi/v5/middleware"
   
   r.Use(middleware.Logger)

2. Recovery Middleware

   • Recovers from panics in your application and returns a 500 Internal Server Error.
   • Ensures that your server doesn't crash and provides a graceful error response.

   r.Use(middleware.Recoverer)

3. CORS Middleware

   • Handles Cross-Origin Resource Sharing (CORS) to allow or restrict resources on a web server to be requested from another domain.
   • Important for web applications that interact with APIs from different origins.

   import "github.com/go-chi/cors"
   
   r.Use(cors.Handler(cors.Options{
      AllowedOrigins:   []string{"https://foo.com"},
      AllowedMethods:   []string{"GET", "POST", "PUT", "DELETE", "OPTIONS"},
      AllowedHeaders:   []string{"Accept", "Authorization", "Content-Type", "X-CSRF-Token"},
      ExposedHeaders:   []string{"Link"},
      AllowCredentials: true,
      MaxAge:           300,
   }))

4. Authentication Middleware

   • Verifies the presence and validity of authentication tokens, such as JWTs.
   • Protects routes to ensure only authenticated users can access certain endpoints.

   func AuthMiddleware(next http.Handler) http.Handler {
      return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
          token := r.Header.Get("Authorization")
          if token == "" {
              http.Error(w, "Forbidden", http.StatusForbidden)
              return
          }
          // Perform token validation...
          next.ServeHTTP(w, r)
      })
   }
   
   r.Use(AuthMiddleware)

5. Rate Limiting Middleware

   • Limits the number of requests a client can make in a given period.
   • Helps protect your server from abuse and ensures fair usage.

   import "github.com/go-chi/httprate"
   
   r.Use(httprate.LimitByIP(100, 1*time.Minute))

6. Request ID Middleware

   • Assigns a unique request ID to each incoming request, useful for tracing and debugging.

   import "github.com/go-chi/chi/v5/middleware"
   
   r.Use(middleware.RequestID)

7. Compression Middleware

   • Compresses HTTP responses to reduce the amount of data transmitted over the network.

   import "github.com/go-chi/chi/v5/middleware"
   
   r.Use(middleware.Compress(5))

Using Middleware in Echo

Here's how you might use some of the same middleware concepts with the Echo framework:

1. Logger and Recover Middleware

   import (
      "github.com/labstack/echo/v4"
      "github.com/labstack/echo/v4/middleware"
   )
   
   e := echo.New()
   e.Use(middleware.Logger())
   e.Use(middleware.Recover())

2. CORS Middleware

   e.Use(middleware.CORSWithConfig(middleware.CORSConfig{
      AllowOrigins: []string{"https://foo.com"},
      AllowMethods: []string{echo.GET, echo.POST, echo.PUT, echo.DELETE},
   }))

3. JWT Authentication Middleware

   e.Use(middleware.JWTWithConfig(middleware.JWTConfig{
      SigningKey: []byte("secret"),
   }))

4. Rate Limiting Middleware

   Echo doesn't have built-in rate limiting, but you can use third-party packages like golang.org/x/time/rate:

   import (
      "golang.org/x/time/rate"
      "github.com/labstack/echo/v4"
   )
   
   rateLimiter := rate.NewLimiter(1, 3) // 1 request per second with a burst of 3
   e.Use(func(next echo.HandlerFunc) echo.HandlerFunc {
      return func(c echo.Context) error {
          if !rateLimiter.Allow() {
              return c.String(http.StatusTooManyRequests, "Too Many Requests")
          }
          return next(c)
      }
   })

Using Middleware in Gorilla Mux

1. Logger Middleware

   import (
      "log"
      "net/http"
      "github.com/gorilla/mux"
   )
   
   func LoggingMiddleware(next http.Handler) http.Handler {
      return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
          log.Println(r.Method, r.URL)
          next.ServeHTTP(w, r)
      })
   }
   
   r := mux.NewRouter()
   r.Use(LoggingMiddleware)

2. Recover Middleware

   func RecoverMiddleware(next http.Handler) http.Handler {
      return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
          defer func() {
              if err := recover(); err != nil {
                  http.Error(w, "Internal Server Error", http.StatusInternalServerError)
              }
          }()
          next.ServeHTTP(w, r)
      })
   }
   
   r := mux.NewRouter()
   r.Use(RecoverMiddleware)

[hardikm9850]

2.A

A router is responsible for directing requests to the correct parts of your application based on the request URL and HTTP method.

Key Concepts of a Router

1. Routes: These are the mappings between a URL pattern and a handler function. For example, you might have a route that maps the URL /users/:id to a function that retrieves a user by their ID.

2. Handlers: These are functions that process incoming HTTP requests and generate responses. In Go, a handler typically has the signature func(w http.ResponseWriter, r *http.Request) for the standard library, but frameworks like Echo use a different signature to provide additional functionality.

3. Path Parameters: These are dynamic segments in the URL that can be captured and passed to the handler. For example, in the route /users/:id, :id is a path parameter.

4. Middleware: Middleware functions are executed before the main handler and can be used for tasks such as logging, authentication, and request modification.

See microservices for the example