Refactor server architecture: move internal logic to pkg/server package

- Simplify cmd/server/main.go from 158 to 57 lines (64% reduction)

- Move HTTP server creation, graceful shutdown, and context management to pkg/server

- Add Run() method to encapsulate server lifecycle management

- Maintain all existing functionality and OpenTelemetry integration

- Improve separation of concerns and code organization

This refactoring makes cmd/server/main.go a thin entrypoint while moving all server implementation details to the pkg/server package, following Go best practices for package organization.

Add server and greet binaries to .gitignore

cmd/server/main.go

@@ -2,19 +2,12 @@ package main
 
 import (
 	"context"
-	"net"
-	"net/http"
 	"os"
-	"os/signal"
-	"syscall"
-	"time"
 
 	"DanceLessonsCoach/pkg/config"
 	"DanceLessonsCoach/pkg/server"
-	"DanceLessonsCoach/pkg/telemetry"
 	"github.com/rs/zerolog"
 	"github.com/rs/zerolog/log"
-	sdktrace "go.opentelemetry.io/otel/sdk/trace"
 )
 
 func main() {
@@ -52,107 +45,13 @@ func main() {
 
 	log.Info().Bool("json_logging", cfg.Logging.JSON).Msg("Logging configured")
 
-	// Initialize OpenTelemetry if enabled
-	var tracerProvider *sdktrace.TracerProvider
-	if cfg.GetTelemetryEnabled() {
-		log.Info().Msg("Initializing OpenTelemetry tracing")
-
-		telemetrySetup := &telemetry.Setup{
-			ServiceName:  cfg.GetServiceName(),
-			OTLPEndpoint: cfg.GetOTLPEndpoint(),
-			Insecure:     cfg.GetTelemetryInsecure(),
-			SamplerType:  cfg.GetSamplerType(),
-			SamplerRatio: cfg.GetSamplerRatio(),
-		}
-
-		var err error
-		if tracerProvider, err = telemetrySetup.InitializeTracing(context.Background()); err != nil {
-			log.Error().Err(err).Msg("Failed to initialize OpenTelemetry, continuing without tracing")
-		} else {
-			log.Info().Msg("OpenTelemetry tracing initialized successfully")
-		}
-	}
-
-	// Setup signal context for graceful shutdown
-	rootCtx, stop := signal.NotifyContext(context.Background(), syscall.SIGINT, syscall.SIGTERM)
-	defer stop()
-
-	// Create root context with cancellation
-	ctx, cancel := context.WithCancel(context.Background())
-	defer cancel()
-
-	// Create ongoing context for active requests
-	ongoingCtx, stopOngoingGracefully := context.WithCancel(context.Background())
-
 	// Create readiness context to control readiness state
 	readyCtx, readyCancel := context.WithCancel(context.Background())
 	defer readyCancel()
 
-	// Start server in goroutine
+	// Create and run server
 	server := server.NewServer(cfg, readyCtx)
-	serverCtx, serverStop := context.WithCancel(ctx)
-
-	go func() {
-		log.Info().Str("address", cfg.GetServerAddress()).Msg("Server running")
-
-		srv := &http.Server{
-			Addr:    cfg.GetServerAddress(),
-			Handler: server.Router(),
-			BaseContext: func(_ net.Listener) context.Context {
-				return ongoingCtx
-			},
-		}
-
-		// Start the HTTP server in a separate goroutine
-		go func() {
-			if err := srv.ListenAndServe(); err != nil && err != http.ErrServerClosed {
-				log.Error().Err(err).Msg("Server error")
-			}
-		}()
-
-		// Wait for signal
-		<-rootCtx.Done()
-		stop()
-		log.Info().Msg("Shutdown signal received")
-
-		// Cancel readiness context to stop accepting new requests
-		readyCancel()
-		log.Info().Msg("Readiness set to false, no longer accepting new requests")
-
-		// Give time for readiness check to propagate (simplified for our case)
-		time.Sleep(1 * time.Second)
-		log.Info().Msg("Readiness check propagated, now waiting for ongoing requests to finish.")
-
-		// Create shutdown context with timeout from config
-		shutdownCtx, shutdownCancel := context.WithTimeout(context.Background(), cfg.Shutdown.Timeout)
-		defer shutdownCancel()
-
-		if err := srv.Shutdown(shutdownCtx); err != nil {
-			log.Error().Err(err).Msg("Server shutdown failed")
-		} else {
-			log.Info().Msg("Server shutdown complete")
-		}
-
-		// Stop ongoing requests context
-		stopOngoingGracefully()
-		cancel()
-		serverStop()
-		log.Info().Msg("Server exited")
-
-		// Shutdown OpenTelemetry tracer provider
-		if tracerProvider != nil {
-			if err := telemetry.Shutdown(context.Background(), tracerProvider); err != nil {
-				log.Error().Err(err).Msg("Failed to shutdown OpenTelemetry tracer provider")
-			} else {
-				log.Info().Msg("OpenTelemetry tracer provider shutdown complete")
-			}
-		}
-
-		// Force log flush by writing to stderr directly
-		// This ensures logs are written before process exits
-		time.Sleep(100 * time.Millisecond)
-	}()
-
-	// Wait for shutdown
-	<-serverCtx.Done()
+	if err := server.Run(); err != nil {
+		log.Fatal().Err(err).Msg("Server failed")
+	}
 }