feat: 启动时自动补齐 config.yaml 缺失的配置项并回写文件

2026-08-28 17:08:09 +08:00
parent 7280650069
commit 99ea9427bd
3 changed files with 203 additions and 15 deletions
@@ -56,6 +56,8 @@ go run .
 | Linux | `/etc/blog_go/config.yaml` | `/srv/blog_go/` |
 | Windows | `./win/etc/blog_go/config.yaml` | `./win/srv/blog_go/` |

+已存在的配置文件若缺少配置项（例如升级前的旧文件没有 `database` 段），启动时会自动用默认值补齐并写回。
+
 ```yaml
 # config.yaml
 database:
@@ -8,6 +8,7 @@ import (
 	"os"
 	"path/filepath"
 	"runtime"
+	"strings"

 	"gopkg.in/yaml.v3"
 )
@@ -54,8 +55,20 @@ var defaultTrustedProxies = []string{"127.0.0.1", "::1"}

 const defaultPort = "8080"

-// mysqlExampleDBName 作为示例写入新建的配置文件。
-const mysqlExampleDBName = "blog_go"
+// MySQL 示例值，用于写入新建配置文件或补齐缺失的数据库段。
+const (
+	mysqlExampleDBName   = "blog_go"
+	mysqlExampleUser     = "user"
+	mysqlExamplePassword = "password"
+	mysqlExampleHost     = "127.0.0.1"
+	mysqlExamplePort     = "3306"
+)
+
+// databaseKeys / webKeys 用于检查配置文件中缺失的子键。
+var (
+	databaseKeys = []string{"type", "db_name", "username", "password", "host", "port"}
+	webKeys      = []string{"port", "socket", "trusted_proxies"}
+)

 // getConfigPath 返回按操作系统区分的配置目录和配置文件路径。
 func getConfigPath() (dir, file string) {
@@ -122,10 +135,10 @@ func LoadConfig(customPath string) *Config {
 			Database: DatabaseConfig{
 				Type:     "sqlite",
 				DBName:   mysqlExampleDBName,
-				Username: "user",
-				Password: "password",
-				Host:     "127.0.0.1",
-				Port:     "3306",
+				Username: mysqlExampleUser,
+				Password: mysqlExamplePassword,
+				Host:     mysqlExampleHost,
+				Port:     mysqlExamplePort,
 			},
 			Web: WebConfig{
 				Port:   defaultPort,
@@ -135,14 +148,7 @@ func LoadConfig(customPath string) *Config {
 			Secret: generateSecret(),
 		}

-		data, err := yaml.Marshal(cfg)
-		if err != nil {
-			log.Fatalf("Failed to marshal default config: %v", err)
-		}
-
-		if err := os.WriteFile(configFile, data, 0640); err != nil {
-			log.Fatalf("Failed to write config file %s: %v", configFile, err)
-		}
+		writeConfigFile(configFile, cfg)
 		// SECURITY_TODO #11：配置文件保存会话密钥；仅允许所有者读取
 		// （install_linux.sh 已应用 0640 权限）。
 		log.Printf("Default config created at %s", configFile)
@@ -158,9 +164,84 @@ func LoadConfig(customPath string) *Config {
 	cfg := &Config{}
 	if err := yaml.Unmarshal(data, cfg); err != nil {
 		log.Printf("Warning: malformed config file %s: %v, using defaults", configFile, err)
+		return applyDefaults(cfg, defaultPath, configFile)
 	}

-	return applyDefaults(cfg, defaultPath, configFile)
+	cfg = applyDefaults(cfg, defaultPath, configFile)
+
+	// 检查配置文件里缺失的键（如旧版本没有 database 段），缺失项自动补全并回写。
+	if missing := missingConfigKeys(data); len(missing) > 0 {
+		fillDatabaseExamples(&cfg.Database)
+		writeConfigFile(configFile, cfg)
+		log.Printf("Config file %s was missing: %s. Added defaults.", configFile, strings.Join(missing, ", "))
+	}
+
+	return cfg
+}
+
+// writeConfigFile 以 0640 权限写入配置文件；已有文件保留原权限。
+func writeConfigFile(configFile string, cfg *Config) {
+	data, err := yaml.Marshal(cfg)
+	if err != nil {
+		log.Fatalf("Failed to marshal config: %v", err)
+	}
+	if err := os.WriteFile(configFile, data, 0640); err != nil {
+		log.Fatalf("Failed to write config file %s: %v", configFile, err)
+	}
+}
+
+// missingConfigKeys 返回配置文件中缺失的键（含顶层与 database/web 子键）。
+// 解析失败时不返回任何缺失（调用方已按 malformed 路径处理）。
+func missingConfigKeys(data []byte) []string {
+	raw := map[string]any{}
+	if err := yaml.Unmarshal(data, &raw); err != nil {
+		return nil
+	}
+	var missing []string
+	if db, ok := raw["database"].(map[string]any); ok {
+		for _, k := range databaseKeys {
+			if _, ok := db[k]; !ok {
+				missing = append(missing, "database."+k)
+			}
+		}
+	} else {
+		missing = append(missing, "database")
+	}
+	if web, ok := raw["web"].(map[string]any); ok {
+		for _, k := range webKeys {
+			if _, ok := web[k]; !ok {
+				missing = append(missing, "web."+k)
+			}
+		}
+	} else {
+		missing = append(missing, "web")
+	}
+	if _, ok := raw["path"]; !ok {
+		missing = append(missing, "path")
+	}
+	return missing
+}
+
+// fillDatabaseExamples 用示例值填充数据库段中的空字段，用于补齐缺失配置后的回写。
+func fillDatabaseExamples(d *DatabaseConfig) {
+	if d.Type == "" {
+		d.Type = "sqlite"
+	}
+	if d.DBName == "" {
+		d.DBName = mysqlExampleDBName
+	}
+	if d.Username == "" {
+		d.Username = mysqlExampleUser
+	}
+	if d.Password == "" {
+		d.Password = mysqlExamplePassword
+	}
+	if d.Host == "" {
+		d.Host = mysqlExampleHost
+	}
+	if d.Port == "" {
+		d.Port = mysqlExamplePort
+	}
 }

 // applyDefaults 以合理的默认值填充零值字段。
@@ -1,9 +1,13 @@
 package config

 import (
+	"bytes"
 	"os"
 	"path/filepath"
+	"strings"
 	"testing"
+
+	"gopkg.in/yaml.v3"
 )

 // TestConfigFileCreatedNotWorldReadable 覆盖 SECURITY_TODO #11：
@@ -34,3 +38,104 @@ func TestMySQLDSN(t *testing.T) {
 		t.Fatalf("MySQLDSN() = %q, want %q", got, want)
 	}
 }
+
+// TestLoadConfigFillsMissingKeys 覆盖启动时补齐缺失配置项并回写文件：
+// 旧格式配置（无 database 段）应被补全，且不覆盖已存在的 path。
+func TestLoadConfigFillsMissingKeys(t *testing.T) {
+	path := filepath.Join(t.TempDir(), "config.yaml")
+	secret := strings.Repeat("a", 64)
+	old := "secret: " + secret + "\npath: ./data\n"
+	if err := os.WriteFile(path, []byte(old), 0640); err != nil {
+		t.Fatalf("write config: %v", err)
+	}
+
+	cfg := LoadConfig(path)
+
+	if cfg.Database.Type != "sqlite" || cfg.Database.DBName != mysqlExampleDBName ||
+		cfg.Database.Username != mysqlExampleUser || cfg.Database.Password != mysqlExamplePassword ||
+		cfg.Database.Host != mysqlExampleHost || cfg.Database.Port != mysqlExamplePort {
+		t.Fatalf("database defaults not filled: %+v", cfg.Database)
+	}
+	if cfg.Web.Port != defaultPort {
+		t.Fatalf("web port = %q, want %q", cfg.Web.Port, defaultPort)
+	}
+	if cfg.Path != "./data" {
+		t.Fatalf("path = %q, want ./data (must not be overwritten)", cfg.Path)
+	}
+
+	st, err := os.Stat(path)
+	if err != nil {
+		t.Fatalf("stat config: %v", err)
+	}
+	if perm := st.Mode().Perm(); perm != 0640 {
+		t.Fatalf("config perms = %v, want 0640", perm)
+	}
+
+	data, err := os.ReadFile(path)
+	if err != nil {
+		t.Fatalf("read config: %v", err)
+	}
+	back := &Config{}
+	if err := yaml.Unmarshal(data, back); err != nil {
+		t.Fatalf("reload config: %v", err)
+	}
+	if back.Database.DBName != mysqlExampleDBName {
+		t.Fatalf("rewritten file db_name = %q, want %q", back.Database.DBName, mysqlExampleDBName)
+	}
+}
+
+// TestLoadConfigKeepsCompleteFile 覆盖配置完整时不回写文件。
+func TestLoadConfigKeepsCompleteFile(t *testing.T) {
+	path := filepath.Join(t.TempDir(), "config.yaml")
+	content := "database:\n" +
+		"  type: mysql\n" +
+		"  db_name: myblog\n" +
+		"  username: root\n" +
+		"  password: p@ss\n" +
+		"  host: db.local\n" +
+		"  port: \"3307\"\n" +
+		"web:\n" +
+		"  port: \"8080\"\n" +
+		"  socket: \"\"\n" +
+		"  trusted_proxies:\n" +
+		"    - 127.0.0.1\n" +
+		"    - ::1\n" +
+		"path: ./data\n" +
+		"secret: " + strings.Repeat("a", 64) + "\n"
+	if err := os.WriteFile(path, []byte(content), 0640); err != nil {
+		t.Fatalf("write config: %v", err)
+	}
+
+	cfg := LoadConfig(path)
+
+	if cfg.Database.Password != "p@ss" {
+		t.Fatalf("password = %q, want p@ss (must not be overwritten)", cfg.Database.Password)
+	}
+	after, err := os.ReadFile(path)
+	if err != nil {
+		t.Fatalf("read config: %v", err)
+	}
+	if !bytes.Equal(after, []byte(content)) {
+		t.Fatalf("complete config file was rewritten:\n%s", after)
+	}
+}
+
+// TestLoadConfigMalformedNoRewrite 覆盖解析失败的配置文件不被回写。
+func TestLoadConfigMalformedNoRewrite(t *testing.T) {
+	path := filepath.Join(t.TempDir(), "config.yaml")
+	// web.port 为序列不能解码到 string，yaml.Unmarshal 报错。
+	content := "secret: " + strings.Repeat("a", 64) + "\nweb:\n  port: [8080]\n"
+	if err := os.WriteFile(path, []byte(content), 0640); err != nil {
+		t.Fatalf("write config: %v", err)
+	}
+
+	LoadConfig(path)
+
+	after, err := os.ReadFile(path)
+	if err != nil {
+		t.Fatalf("read config: %v", err)
+	}
+	if !bytes.Equal(after, []byte(content)) {
+		t.Fatalf("malformed config was rewritten:\n%s", after)
+	}
+}