完善数据库 SQL 约束与运维治理

backend/internal/config/config.go

@@ -5,6 +5,7 @@ import (
 	"os"
 	"strconv"
 	"strings"
+	"time"
 )
 
 type Config struct {
@@ -29,6 +30,7 @@ type Config struct {
 	Realname                   RealnameConfig
 	Log                        LogConfig
 	RateLimit                  RateLimitConfig
+	Database                   DatabaseConfig
 	BackupStatusFile           string
 }
 
@@ -70,6 +72,14 @@ type RateLimitConfig struct {
 	RequestsPerMinute int
 }
 
+type DatabaseConfig struct {
+	MaxOpenConns       int
+	MaxIdleConns       int
+	ConnMaxLifetime    time.Duration
+	ConnMaxIdleTime    time.Duration
+	SlowQueryThreshold time.Duration
+}
+
 func Load() Config {
 	return Config{
 		AppEnv:                     getEnv("APP_ENV", "development"),
@@ -131,6 +141,13 @@ func Load() Config {
 			Enabled:           getEnvBool("RATE_LIMIT_ENABLED", true),
 			RequestsPerMinute: getEnvInt("RATE_LIMIT_REQUESTS_PER_MINUTE", 300),
 		},
+		Database: DatabaseConfig{
+			MaxOpenConns:       getEnvIntMin("DATABASE_MAX_OPEN_CONNS", 50, 1),
+			MaxIdleConns:       getEnvIntMin("DATABASE_MAX_IDLE_CONNS", 10, 0),
+			ConnMaxLifetime:    time.Duration(getEnvIntMin("DATABASE_CONN_MAX_LIFETIME_MINUTES", 30, 1)) * time.Minute,
+			ConnMaxIdleTime:    time.Duration(getEnvIntMin("DATABASE_CONN_MAX_IDLE_TIME_MINUTES", 5, 0)) * time.Minute,
+			SlowQueryThreshold: time.Duration(getEnvIntMin("DATABASE_SLOW_QUERY_THRESHOLD_MS", 500, 1)) * time.Millisecond,
+		},
 		BackupStatusFile: getEnv("BACKUP_STATUS_FILE", "/var/run/hfb-backup-status/status.json"),
 	}
 }
@@ -208,6 +225,14 @@ func getEnvInt(key string, fallback int) int {
 	return parsed
 }
 
+func getEnvIntMin(key string, fallback, minimum int) int {
+	value := getEnvInt(key, fallback)
+	if value < minimum {
+		return fallback
+	}
+	return value
+}
+
 func getEnvBool(key string, fallback bool) bool {
 	value := os.Getenv(key)
 	if value == "" {