split server startup helpers

cmd/server/startup.go

@@ -0,0 +1,46 @@
+package main
+
+import (
+	"context"
+	"database/sql"
+	"runtime"
+	"time"
+
+	"go.uber.org/zap"
+
+	"github.com/ShukeBta/MediaStationGo/internal/config"
+)
+
+func applyCPUThreadLimit(cfg *config.Config, logger *zap.Logger) {
+	if cfg == nil || cfg.App.MaxCPUThreads < 1 {
+		return
+	}
+	prev := runtime.GOMAXPROCS(cfg.App.MaxCPUThreads)
+	if logger != nil {
+		logger.Info("runtime CPU thread limit applied",
+			zap.Int("max_cpu_threads", cfg.App.MaxCPUThreads),
+			zap.Int("previous", prev))
+	}
+}
+
+func waitForDatabase(db interface{ DB() (*sql.DB, error) }, logger *zap.Logger) error {
+	sqlDB, err := db.DB()
+	if err != nil {
+		return err
+	}
+	var lastErr error
+	for attempt := 1; attempt <= 30; attempt++ {
+		ctx, cancel := context.WithTimeout(context.Background(), 3*time.Second)
+		err = sqlDB.PingContext(ctx)
+		cancel()
+		if err == nil {
+			return nil
+		}
+		lastErr = err
+		if logger != nil {
+			logger.Warn("database not ready; retrying", zap.Int("attempt", attempt), zap.Error(err))
+		}
+		time.Sleep(time.Duration(attempt) * 500 * time.Millisecond)
+	}
+	return lastErr
+}