micro/cmd/protoc-gen-micro/README.md
Vasiliy Tolstov 06136312bb
regen files with never protoc (#6)
* regen files with never protoc
* rewrite import path

Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>
2020-08-19 17:47:17 +03:00

139 lines
3.1 KiB
Markdown

# protoc-gen-micro
This is protobuf code generation for micro. We use protoc-gen-micro to reduce boilerplate code.
## Install
```
go get github.com/micro/micro/v3/cmd/protoc-gen-micro@master
```
Also required:
- [protoc](https://github.com/google/protobuf)
- [protoc-gen-go](https://github.com/golang/protobuf)
## Usage
Define your service as `greeter.proto`
```
syntax = "proto3";
service Greeter {
rpc Hello(Request) returns (Response) {}
}
message Request {
string name = 1;
}
message Response {
string msg = 1;
}
```
Generate the code
```
protoc --proto_path=$GOPATH/src:. --micro_out=. --go_out=. greeter.proto
```
Your output result should be:
```
./
greeter.proto # original protobuf file
greeter.pb.go # auto-generated by protoc-gen-go
greeter.micro.go # auto-generated by protoc-gen-micro
```
The micro generated code includes clients and handlers which reduce boiler plate code
### Server
Register the handler with your micro server
```go
type Greeter struct{}
func (g *Greeter) Hello(ctx context.Context, req *proto.Request, rsp *proto.Response) error {
rsp.Msg = "Hello " + req.Name
return nil
}
proto.RegisterGreeterHandler(service.Server(), &Greeter{})
```
### Client
Create a service client with your micro client
```go
client := proto.NewGreeterService("greeter", service.Client())
```
### Errors
If you see an error about `protoc-gen-micro` not being found or executable, it's likely your environment may not be configured correctly. If you've already installed `protoc`, `protoc-gen-go`, and `protoc-gen-micro` ensure you've included `$GOPATH/bin` in your `PATH`.
Alternative specify the Go plugin paths as arguments to the `protoc` command
```
protoc --plugin=protoc-gen-go=$GOPATH/bin/protoc-gen-go --plugin=protoc-gen-micro=$GOPATH/bin/protoc-gen-micro --proto_path=$GOPATH/src:. --micro_out=. --go_out=. greeter.proto
```
### Endpoint
Add a micro API endpoint which routes directly to an RPC method
Usage:
1. Clone `github.com/googleapis/googleapis` to use this feature as it requires http annotations.
2. The protoc command must include `-I$GOPATH/src/github.com/googleapis/googleapis` for the annotations import.
```diff
syntax = "proto3";
import "google/api/annotations.proto";
service Greeter {
rpc Hello(Request) returns (Response) {
option (google.api.http) = { post: "/hello"; body: "*"; };
}
}
message Request {
string name = 1;
}
message Response {
string msg = 1;
}
```
The proto generates a `RegisterGreeterHandler` function with a [api.Endpoint](https://godoc.org/github.com/micro/go-micro/api#Endpoint).
```diff
func RegisterGreeterHandler(s server.Server, hdlr GreeterHandler, opts ...server.HandlerOption) error {
type greeter interface {
Hello(ctx context.Context, in *Request, out *Response) error
}
type Greeter struct {
greeter
}
h := &greeterHandler{hdlr}
opts = append(opts, api.WithEndpoint(&api.Endpoint{
Name: "Greeter.Hello",
Path: []string{"/hello"},
Method: []string{"POST"},
Handler: "rpc",
}))
return s.Handle(s.NewHandler(&Greeter{h}, opts...))
}
```
## LICENSE
protoc-gen-micro is a liberal reuse of protoc-gen-go hence we maintain the original license