Init V4 community edition (#2265)

* Init V4 community edition

* Init V4 community edition

application/migrator/conf/defaults.go

@@ -0,0 +1,55 @@
+package conf
+
+// RedisConfig Redis服务器配置
+var RedisConfig = &redis{
+	Network:  "tcp",
+	Server:   "",
+	Password: "",
+	DB:       "0",
+}
+
+// DatabaseConfig 数据库配置
+var DatabaseConfig = &database{
+	Type:       "UNSET",
+	Charset:    "utf8",
+	DBFile:     "cloudreve.db",
+	Port:       3306,
+	UnixSocket: false,
+}
+
+// SystemConfig 系统公用配置
+var SystemConfig = &system{
+	Debug:       false,
+	Mode:        "master",
+	Listen:      ":5212",
+	ProxyHeader: "X-Forwarded-For",
+}
+
+// CORSConfig 跨域配置
+var CORSConfig = &cors{
+	AllowOrigins:     []string{"UNSET"},
+	AllowMethods:     []string{"PUT", "POST", "GET", "OPTIONS"},
+	AllowHeaders:     []string{"Cookie", "X-Cr-Policy", "Authorization", "Content-Length", "Content-Type", "X-Cr-Path", "X-Cr-FileName"},
+	AllowCredentials: false,
+	ExposeHeaders:    nil,
+	SameSite:         "Default",
+	Secure:           false,
+}
+
+// SlaveConfig 从机配置
+var SlaveConfig = &slave{
+	CallbackTimeout: 20,
+	SignatureTTL:    60,
+}
+
+var SSLConfig = &ssl{
+	Listen:   ":443",
+	CertPath: "",
+	KeyPath:  "",
+}
+
+var UnixConfig = &unix{
+	Listen: "",
+}
+
+var OptionOverwrite = map[string]interface{}{}