grpcurl是一个命令行工具，使用它可以在命令行中访问gRPC服务，就像使用curl访问http服务一样。

准备: 在gRPC服务中注册reflection服务
gRPC服务是使用Protobuf(PB)协议的，而PB提供了在运行时获取Proto定义信息的反射功能。grpc-go中的”google.golang.org/grpc/reflection”包就对这个反射功能提供了支持。

server := grpc.NewServer()
// 注册grpcurl所需的reflection服务
reflection.Register(server)
// 注册业务服务
proto.RegisterGreeterServer(server, &greeter{})

1,grpcurl 127.0.0.1:57904 list
Failed to dial target host “127.0.0.1:57904”: tls: first record does not look like a TLS handshake
原因grpc默认是https

2，grpcurl -plaintext 127.0.0.1:57904 list
grpc.health.v1.Health
grpc.reflection.v1alpha.ServerReflection
xxx.svc.xx.XXService

加-plaintext 走http 解决

3，grpcurl -plaintext 127.0.0.1:57904 list xxx.svc.xx.XXService
xxx.svc.xx.XXService.xxMethod
xxx.svc.xx.XXService.yyMethod
前提是服务端起了reflection

4,grpcurl -plaintext 127.0.0.1:57904 xxx.svc.xx.XXService/yyMethod
ERROR:
Code: InvalidArgument
Message: xxx
缺少参数

5，grpcurl -plaintext 127.0.0.1:57904 describe xxx.svc.xx.XXService
e xxx.svc.xx.XXService is a service:
service XXService {
rpc yyMethod ( .google.protobuf.Empty ) returns ( .google.protobuf.Empty );

6，grpcurl -plaintext 127.0.0.1:57904 describe xxx.svc.xx.XXService.yyMethod

xxx.svc.xx.XXService.yyMethod is a method:
rpc yyMethod ( .xxx.svc.xx.XXService.yyMethodRequest ) returns ( .xxx.svc.xx.XXService.yyMethodResponse );

7.grpcurl -plaintext 127.0.0.1:57904 describe .xxx.svc.xx.yyMethodRequest

.xxx.svc.xx.yyMethodRequest is a message:
message yyMethodRequest {
string xxx = 1;
int64 yyy = 2;
}

8.grpcurl -plaintext 127.0.0.1:57904 -d ‘{“xxx”:”12133”,”yyy”:0}’ xxx.svc.xx.XXService/yyMethod
Too many arguments.

原因：请求参数位置不对

9，grpcurl -plaintext -d ‘{“xxx”:”12133”,”yyy”:0}’ 127.0.0.1:57904 xxx.svc.xx.XXService/yyMethod

ERROR:
Code: PermissionDenied
原因 缺少meta参数（header）

10.grpcurl -plaintext -d ‘{“xxx”:”12133”,”yyy”:0}’ -H ‘“Xx”:1234’ 127.0.0.1:57904 xxx.svc.xx.XXService/yyMethod

Error invoking method “xxx.svc.xx.XXService/yyMethod”: rpc error: code = Internal desc = failed to query for service descriptor “xxx.svc.xx.XXService/yyMethod”: stream terminated by RST_STREAM with error code: PROTOCOL_ERROR

原因：没有指定proto 文件

11.grpcurl -plaintext -d ‘{“xxx”:”12133”,”yyy”:0}’ -H ‘“Xx”:1234’ -proto “~/go/protos/xxx.proto” 127.0.0.1:57904 xxx.svc.xx.XXService/yyMethod

Failed to process proto source files.: could not parse given files: %!v(PANIC=Error method: runtime error: invalid memory address or nil pointer dereference)

原因：没有指定依赖文件的目录

1. grpcurl -plaintext -d ‘{“xxx”:”12133”,”yyy”:0}’ -H ‘“Xx”:1234’ -import-path “/go/protos/” -proto “/go/protos/xxx.proto” 127.0.0.1:57904 xxx.svc.xx.XXService/yyMethod
   ERROR:
   Code: Internal
   Message: stream terminated by RST_STREAM with error code: PROTOCOL_ERROR

原因：header 错误，原因header 里多了“

1. grpcurl -plaintext -emit-defaults 127.0.0.1:57904 xxx.svc.xx.XXService/yyMethod
   ERROR:
   Code: InvalidArgument
   Message: xxx or yyy is required

14.grpcurl -plaintext -d ‘{“xxx”:”12133”,”yyy”:0}’ -H ‘Xx:1234’ -import-path “/go/protos/” -proto “/go/protos/xxx.proto” 127.0.0.1:57904 xxx.svc.xx.XXService/yyMethod
问题解决

参考：
https://blog.csdn.net/weixin_30878501/article/details/94952412
https://www.cnblogs.com/highend/p/grpc_call_protocol_error.html
https://github.com/fullstorydev/grpcurl
https://about.sourcegraph.com/go/gophercon-2018-grpc-reflection-and-grpcurl/
https://github.com/fullstorydev/grpcurl/blob/master/README.md
https://blog.frognew.com/2020/04/grpcurl.html

https://github.com/xiazemin/lean_record/blob/main/grpcurl