e4.0.0 Refactored, file watcher and improved builder, doc update

2025-07-17 03:44:08 -04:00
parent 16dc829fd5
commit 2934ea9548
25 changed files with 3567 additions and 1828 deletions
--- a/cmd/main.go
+++ b/cmd/main.go
@ -0,0 +1,168 @@
+// FILE: example/watch_demo.go
+package main
+
+import (
+	"context"
+	"errors"
+	"log"
+	"os"
+	"os/signal"
+	"syscall"
+	"time"
+
+	"github.com/lixenwraith/config"
+)
+
+// AppConfig represents our application configuration
+type AppConfig struct {
+	Server struct {
+		Host string `toml:"host"`
+		Port int    `toml:"port"`
+	} `toml:"server"`
+
+	Database struct {
+		URL         string        `toml:"url"`
+		MaxConns    int           `toml:"max_conns"`
+		IdleTimeout time.Duration `toml:"idle_timeout"`
+	} `toml:"database"`
+
+	Features struct {
+		RateLimit bool `toml:"rate_limit"`
+		Caching   bool `toml:"caching"`
+	} `toml:"features"`
+}
+
+func main() {
+	// Create configuration with defaults
+	defaults := &AppConfig{}
+	defaults.Server.Host = "localhost"
+	defaults.Server.Port = 8080
+	defaults.Database.MaxConns = 10
+	defaults.Database.IdleTimeout = 30 * time.Second
+
+	// Build configuration
+	cfg, err := config.NewBuilder().
+		WithDefaults(defaults).
+		WithEnvPrefix("MYAPP_").
+		WithFile("config.toml").
+		Build()
+	if err != nil && !errors.Is(err, config.ErrConfigNotFound) {
+		log.Fatal("Failed to load config:", err)
+	}
+
+	// Enable auto-update with custom options
+	watchOpts := config.WatchOptions{
+		PollInterval:      500 * time.Millisecond, // Check twice per second
+		Debounce:          200 * time.Millisecond, // Quick response
+		MaxWatchers:       10,
+		ReloadTimeout:     2 * time.Second,
+		VerifyPermissions: true, // SECURITY: Detect permission changes
+	}
+	cfg.AutoUpdateWithOptions(watchOpts)
+	defer cfg.StopAutoUpdate()
+
+	// Start watching for changes
+	changes := cfg.Watch()
+
+	// Context for graceful shutdown
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	// Handle signals
+	sigCh := make(chan os.Signal, 1)
+	signal.Notify(sigCh, syscall.SIGINT, syscall.SIGTERM)
+
+	// Log initial configuration
+	logConfig(cfg)
+
+	// Watch for changes
+	go func() {
+		for {
+			select {
+			case <-ctx.Done():
+				return
+			case path := <-changes:
+				handleConfigChange(cfg, path)
+			}
+		}
+	}()
+
+	// Main loop
+	log.Println("Watching for configuration changes. Edit config.toml to see updates.")
+	log.Println("Press Ctrl+C to exit.")
+
+	ticker := time.NewTicker(10 * time.Second)
+	defer ticker.Stop()
+
+	for {
+		select {
+		case <-sigCh:
+			log.Println("Shutting down...")
+			return
+
+		case <-ticker.C:
+			// Periodic health check
+			var port int64
+			port, _ = cfg.Get("server.port")
+			log.Printf("Server still running on port %d", port)
+		}
+	}
+}
+
+func handleConfigChange(cfg *config.Config, path string) {
+	switch path {
+	case "__file_deleted__":
+		log.Println("⚠️  Config file was deleted!")
+	case "__permissions_changed__":
+		log.Println("⚠️  SECURITY: Config file permissions changed!")
+	case "__reload_error__":
+		log.Printf("❌ Failed to reload config: %s", path)
+	case "__reload_timeout__":
+		log.Println("⚠️  Config reload timed out")
+	default:
+		// Normal configuration change
+		value, _ := cfg.Get(path)
+		log.Printf("📝 Config changed: %s = %v", path, value)
+
+		// Handle specific changes
+		switch path {
+		case "server.port":
+			log.Println("Port changed - server restart required")
+		case "database.url":
+			log.Println("Database URL changed - reconnection required")
+		case "features.rate_limit":
+			if cfg.Bool("features.rate_limit") {
+				log.Println("Rate limiting enabled")
+			} else {
+				log.Println("Rate limiting disabled")
+			}
+		}
+	}
+}
+
+func logConfig(cfg *config.Config) {
+	log.Println("Current configuration:")
+	log.Printf("  Server: %s:%d", cfg.String("server.host"), cfg.Int("server.port"))
+	log.Printf("  Database: %s (max_conns=%d)",
+		cfg.String("database.url"),
+		cfg.Int("database.max_conns"))
+	log.Printf("  Features: rate_limit=%v, caching=%v",
+		cfg.Bool("features.rate_limit"),
+		cfg.Bool("features.caching"))
+}
+
+// Example config.toml file:
+/*
+[server]
+host = "localhost"
+port = 8080
+
+[database]
+url = "postgres://localhost/myapp"
+max_conns = 25
+idle_timeout = "30s"
+
+[features]
+rate_limit = true
+caching = false
+*/