代码实现
cors 的代码超级简单，就一个 cors.go，内容也只有一点点：
// DefaultAllowedOrigins is the default origins allowed for the Dapr HTTP servers
const DefaultAllowedOrigins = "*"
AllowedOrigins配置的读取
AllowedOrigins 配置在启动时通过命令行参数 allowed-origins 传入，默认值为 DefaultAllowedOrigins （"*"）。然后传入给 NewRuntimeConfig（）方法：
func FromFlags() (*DaprRuntime, error) {
allowedOrigins := flag.String("allowed-origins", cors.DefaultAllowedOrigins, "Allowed HTTP origins")
runtimeConfig := NewRuntimeConfig(*appID, placementAddresses, *controlPlaneAddress, *allowedOrigins ......)
}
之后保存在 NewRuntimeConfig 的 AllowedOrigins 字段中：
func NewRuntimeConfig(
id string, placementAddresses []string,
controlPlaneAddress, allowedOrigins ......) *Config {
return &Config{
AllowedOrigins: allowedOrigins,
......
}
AllowedOrigins配置的使用
pkg/http/server.go 的 useCors() 方法：
func (s *server) useCors(next fasthttp.RequestHandler) fasthttp.RequestHandler {
if s.config.AllowedOrigins == cors_dapr.DefaultAllowedOrigins {
return next
}
log.Infof("enabled cors http middleware")
origins := strings.Split(s.config.AllowedOrigins, ",")
corsHandler := s.getCorsHandler(origins)
return corsHandler.CorsMiddleware(next)
}