package main import ( "fmt" "os" "reflect" ) type Config struct { HttpListen string `env:"BAGAGE_HTTP_LISTEN" default:":8080"` DavPath string `env:"BAGAGE_WEBDAV_PREFIX" default:"/webdav"` LdapServer string `env:"BAGAGE_LDAP_ENDPOINT" default:"127.0.0.1:1389"` UserBaseDN string `env:"BAGAGE_LDAP_USER_BASE_DN" default:"ou=users,dc=deuxfleurs,dc=fr"` UserNameAttr string `env:"BAGAGE_LDAP_USERNAME_ATTR" default:"cn"` Endpoint string `env:"BAGAGE_S3_ENDPOINT" default:"garage.deuxfleurs.fr"` UseSSL bool `env:"BAGAGE_S3_SSL" default:"true"` } func (c *Config) LoadWithDefault() *Config { c.iter(func(t reflect.StructField, v reflect.Value) { tag := t.Tag.Get("default") if tag == "" { return } else { setKey(v, tag) } }) return c } func (c *Config) LoadWithEnv() *Config { c.iter(func(t reflect.StructField, v reflect.Value) { tag := t.Tag.Get("env") if tag == "" { return } else if val, ok := os.LookupEnv(tag); ok { setKey(v, val) } }) return c } func (c *Config) String() (rep string) { rep = "Configuration:\n" c.iter(func(t reflect.StructField, v reflect.Value) { rep += "\t" + t.Name + ": " if t.Type.Kind() == reflect.Bool { rep += fmt.Sprintf("%v", v.Bool()) + "\n" } else { rep += "\"" + v.String() + "\"\n" } }) return } func (c *Config) iter(cb func(t reflect.StructField, v reflect.Value)) { t := reflect.ValueOf(c).Elem() for i := 0; i < t.Type().NumField(); i++ { field := t.Field(i) typeField := t.Type().Field(i) cb(typeField, field) } } func setKey(v reflect.Value, e string) { if v.Type().Kind() == reflect.String { v.SetString(e) } else if v.Type().Kind() == reflect.Bool { v.SetBool(e == "true") } else { panic("Unsupported type") } }