如何将gin gonic中的原始数据传递给gRPC微服务？

huangapple
go评论104阅读模式
英文:

How can I pass the origin from gin gonic to a gRPC microservice

问题

我正在编写一个支持多个来源的微服务（这些来源定义了要连接的数据库）。为了做到这一点，我需要获取来源信息。使用gin作为服务器负责验证来源，而rpc微服务不验证任何内容。我唯一遗漏的是如何将这些元数据传递给上下文中的rpc服务。

我尽量简化了这个想法，实际情况要复杂得多，并且有多个值要传递。将所有这些内容传递给所有函数是不可行的，因为这会产生太多的开销。

Gin服务器

  1. func OriginMiddleware() gin.HandlerFunc {
  2. 	return func(context *gin.Context) {
  4. 		origin := context.GetHeader("origin")
  5. 		
  6.         // 将origin添加到上下文中
  8. 		context.Next()
  9. 	}
  10. }
  12. func main(){
  13.     
  14.     ...  // 设置grpc等
  16.     
  17. 	r.Use(OriginMiddleware())
  19. 	r.POST("/login", User.Login)
  20. 	r.GET("/getUser", User.Get)
  22.     ... // 其他许多端点
  24. 	r.Run("localhost:8080")
  25. }

微服务

  2. func OriginInterceptor() grpc.UnaryServerInterceptor {
  3. 	return func(ctx context.Context, req interface{}, info *grpc.UnaryServerInfo, handler grpc.UnaryHandler) (resp interface{}, err error) {
  4. 		origin := ctx.Value("origin")
  5. 		fmt.Println(origin)
  6.     
  7.         ... // 获取或创建数据库连接等操作
  8.  
  9. 		return handler(ctx, req)
  10. 	}
  11. }
  13. func main() {
  14.     ... // 设置
  15.     
  16. 	s := grpc.NewServer(grpc.UnaryInterceptor(MongoInterceptor()))
  17. 	
  18.     UserPB.RegisterUserServiceServer(s, &server{})
  20. 	... // 启动服务
  21. }

我尝试过的方法

  • 重写gin上下文似乎是不可能的
  • 使用.Set只在"gin"服务器内部有效，但在发送到grpc时所有值都丢失了
英文:

I'm writing a microservice that supports multiple origins (which then define what database to connect to). In order to do that I need for example the origin. The server with gin is responsible to validate the origin, the rpc microservice does not validate anything. The only point that I am missing is how to pass this metadata to the rpc service inside the context.

I simplified the idea as much as I could, the real case is way more complex, and there is more than 1 value to pass. Passing all those things to all functions is out of discussion, as it would generate way too much overhead

Gin server

  1. func OriginMiddleware() gin.HandlerFunc {
  2. 	return func(context *gin.Context) {
  4. 		origin := context.GetHeader("origin")
  5. 		
  6.         // add origin to the context
  8. 		context.Next()
  9. 	}
  10. }
  12. func main(){
  13.     
  14.     ...  // setup grpc etc
  16.     
  17. 	r.Use(OriginMiddleware())
  19. 	r.POST("/login", User.Login)
  20. 	r.GET("/getUser", User.Get)
  22.     ... // many other endpoints
  24. 	r.Run("localhost:8080")
  25. }

Microservice

  2. func OriginInterceptor() grpc.UnaryServerInterceptor {
  3. 	return func(ctx context.Context, req interface{}, info *grpc.UnaryServerInfo, handler grpc.UnaryHandler) (resp interface{}, err error) {
  4. 		origin := ctx.Value("origin")
  5. 		fmt.Println(origin)
  6.     
  7.         ... // get or create db connection whatsoever
  8.  
  9. 		return handler(ctx, req)
  10. 	}
  11. }
  13. func main() {
  14.     ... // setup
  15.     
  16. 	s := grpc.NewServer(grpc.UnaryInterceptor(MongoInterceptor()))
  17. 	
  18.     UserPB.RegisterUserServiceServer(s, &server{})
  20. 	... // serve
  21. }

What I've been trying

  • Overwriting the gin context doesn't seem possible
  • Using .Set works only as long as it's inside the "gin" server, but all values are lost when sent to grpc

答案1

得分: 1

我找到了一个可行的解决方案，但并不是最干净的。欢迎提出改进和批评意见！

  1. func ToGrpcContext(ctx *gin.Context) context.Context {
  2. 	res := make(map[string]string)
  3. 	for key, value := range ctx.Keys {
  4. 		switch v := value.(type) {
  5. 		case string:
  6. 			res[key] = v
  7. 		}
  8. 	}
  9. 	return metadata.NewOutgoingContext(ctx, metadata.New(res))
  10. }

每次调用任何grpc函数时，我都会使用这个辅助函数包装上下文，例如：

  1. user, err := UserPB.GetUser(ToGrpcContext(ctx), &UserPB.GetUserInput{...})
英文:

I found a solution that works, but it's not the cleanest. Improvements and critics are well accepted!

  1. func ToGrpcContext(ctx *gin.Context) context.Context {
  2. 	res := make(map[string]string)
  3. 	for key, value := range ctx.Keys {
  4. 		switch v := value.(type) {
  5. 		case string:
  6. 			res[key] = v
  7. 		}
  8. 	}
  9. 	return metadata.NewOutgoingContext(ctx, metadata.New(res))
  10. }

Each time I call any grpc function, I wrap the context with this helper function, like:

  1. user, err := UserPB.GetUser(ToGrpcContext(ctx), &UserPB.GetUserInput{...})

huangapple
  • 本文由 发表于 2022年2月19日 18:50:24
  • 转载请务必保留本文链接：https://go.coder-hub.com/71184277.html
  • go
  • go-gin
  • grpc
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