api

API Server Design and Structure

Overview

The API server is a RESTful service built with Go, using the Gorilla Mux router for routing and Ent for database operations. The server follows a modular design with clear separation of concerns and dependency injection patterns.

Server Initialization

The API server is initialized in cmd/api-server/main.go. It follows these steps:

1. Load environment variables
2. Initialize logger
3. Connect to database
4. Create and configure server
5. Start server and handle graceful shutdown

func main() {
    // Load environment variables
    if err := godotenv.Load(envFile); err != nil {
        log.Printf("Warning: Error loading .env file: %v", err)
    }

    // Initialize logger
    logger, err := zap.NewProduction()
    if err != nil {
        log.Fatalf("Failed to initialize logger: %v", err)
    }
    defer logger.Sync()

    // Initialize database connection
    client, err := database.NewClient(logger)
    if err != nil {
        logger.Fatal("Failed to connect to database", zap.Error(err))
    }
    defer client.Close()

    // Create server config
    config := server.NewConfig()

    // Create and configure server
    srv := server.NewServer(config, logger, client)

    // Run server in a goroutine
    go func() {
        if err := srv.Start(); err != nil {
            logger.Fatal("Server failed", zap.Error(err))
        }
    }()

    // Handle graceful shutdown
    c := make(chan os.Signal, 1)
    signal.Notify(c, os.Interrupt, syscall.SIGTERM)
    sig := <-c
    
    ctx, cancel := context.WithTimeout(context.Background(), time.Second*15)
    defer cancel()
    
    if err := srv.Shutdown(ctx); err != nil {
        logger.Fatal("Server forced to shutdown", zap.Error(err))
    }
}

Server Configuration

Server configuration is managed through the Config struct in internal/server/config.go. It loads settings from environment variables with sensible defaults.

type Config struct {
    Host          string
    Port          string
    ReadTimeout   time.Duration
    WriteTimeout  time.Duration
    IdleTimeout   time.Duration
    RunMigrations bool
}

func NewConfig() *Config {
    port := os.Getenv("SERVER_PORT")
    if port == "" {
        port = "8080"
    }

    host := os.Getenv("SERVER_HOST")
    if host == "" {
        host = "localhost"
    }

    return &Config{
        Host:          host,
        Port:          port,
        ReadTimeout:   15 * time.Second,
        WriteTimeout:  15 * time.Second,
        IdleTimeout:   60 * time.Second,
        RunMigrations: false,
    }
}