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 == "" {

backend/internal/config/config_test.go

@@ -26,6 +26,41 @@ func TestIsProductionEnv(t *testing.T) {
 	}
 }
 
+func TestLoadDatabaseConfigFromEnvironment(t *testing.T) {
+	t.Setenv("DATABASE_MAX_OPEN_CONNS", "80")
+	t.Setenv("DATABASE_MAX_IDLE_CONNS", "16")
+	t.Setenv("DATABASE_CONN_MAX_LIFETIME_MINUTES", "45")
+	t.Setenv("DATABASE_CONN_MAX_IDLE_TIME_MINUTES", "7")
+	t.Setenv("DATABASE_SLOW_QUERY_THRESHOLD_MS", "750")
+
+	cfg := Load()
+	if cfg.Database.MaxOpenConns != 80 || cfg.Database.MaxIdleConns != 16 {
+		t.Fatalf("database pool = %+v, want open=80 idle=16", cfg.Database)
+	}
+	if cfg.Database.ConnMaxLifetime.Minutes() != 45 || cfg.Database.ConnMaxIdleTime.Minutes() != 7 {
+		t.Fatalf("database lifetimes = %s/%s, want 45m/7m", cfg.Database.ConnMaxLifetime, cfg.Database.ConnMaxIdleTime)
+	}
+	if cfg.Database.SlowQueryThreshold.Milliseconds() != 750 {
+		t.Fatalf("slow query threshold = %s, want 750ms", cfg.Database.SlowQueryThreshold)
+	}
+}
+
+func TestLoadDatabaseConfigInvalidValuesUseDefaults(t *testing.T) {
+	t.Setenv("DATABASE_MAX_OPEN_CONNS", "0")
+	t.Setenv("DATABASE_MAX_IDLE_CONNS", "-1")
+	t.Setenv("DATABASE_CONN_MAX_LIFETIME_MINUTES", "0")
+	t.Setenv("DATABASE_CONN_MAX_IDLE_TIME_MINUTES", "-1")
+	t.Setenv("DATABASE_SLOW_QUERY_THRESHOLD_MS", "0")
+
+	cfg := Load()
+	if cfg.Database.MaxOpenConns != 50 || cfg.Database.MaxIdleConns != 10 {
+		t.Fatalf("invalid pool values = %+v, want defaults open=50 idle=10", cfg.Database)
+	}
+	if cfg.Database.ConnMaxLifetime.Minutes() != 30 || cfg.Database.ConnMaxIdleTime.Minutes() != 5 || cfg.Database.SlowQueryThreshold.Milliseconds() != 500 {
+		t.Fatalf("invalid database durations = %+v, want defaults", cfg.Database)
+	}
+}
+
 // TestFieldEncryptionLegacyKeyNonProductionDefaultsToHistoric 验证非生产环境未设置 legacy 时
 // 回退到历史硬编码密钥（开发态零配置兼容旧密文）。
 func TestFieldEncryptionLegacyKeyNonProductionDefaultsToHistoric(t *testing.T) {