2.python + grpc-gateway

python + grpc-gateway 1. 前言2. 新建用户3. 安装工具4. 开始创建helloworld:5.测试6.总结

1. 前言

今天在网上看了硬是没找到使用python代码的grpc-gateway，只能试着使用go的grpc-gateway
监听python grpc服务，不过grpc-gateway本身就是一个插件，使用go的话问题应该也不大。

2. 新建用户

[test@localhost ~]$ useradd test	# 新建 test 用户
[test@localhost ~]$ passwd test		# 修改密码
[test@localhost ~]$ sudo vim /etc/sudoer	# 为 test 用户增加  sudo 权限，使用wq!保存
# 省略前面部分 ...
## Allow root to run any commands anywhere 
root    ALL=(ALL)       ALL
test	ALL=(ALL)		ALL
# 省略后面部分 ...
[test@localhost ~]$ su - test		# 切换至 test 用户

3. 安装工具

最好是有科学上网，这样下载会快很多。

安装golang

[test@localhost ~]$ sudo yum install golang -y
[test@localhost ~]$go version
go version go1.13.3 linux/amd64

安装grpcio grpcio-tools

[test@localhost ~]$ sudo pip3 install grpcio grpcio-tools

安装 grpc-gateway

[test@localhost ~]$ echo -e "export GOPROXY=https://goproxy.cn\nGOPATH=\$(go env \
GOPATH)\nPATH=\${PATH}:\$(go env GOPATH)/bin" >> ~/.bashrc && source ~/.bashrc
[test@localhost ~]$ curl https://raw.githubusercontent.com/1397436824/\
grpc-gateway-sh/main/install-grpc-gateway.sh | bash

安装protoc-gen-go、protoc-gen-go-grpc

go install google.golang.org/protobuf/cmd/protoc-gen-go
go install google.golang.org/grpc/cmd/protoc-gen-go-grpc

更新为go1.17.2，如果比这个版本更新，可以不做 *** 作

[test@localhost ~]$ go get golang.org/dl/go1.17.2@latest
[test@localhost ~]$ ~/go/bin/go1.17.2 download
[test@localhost ~]$ sudo unlink /bin/go
[test@localhost ~]$ sudo ln -s ~/go/bin/go1.17.2 /bin/go
[test@localhost ~]$ go version
go version go1.17.2 linux/arm64

4. 开始创建helloworld: 生成stubs源码

[test@localhost ~]$ mkdir helloworld && cd helloworld
[test@localhost helloworld]$ go mod init github.com/test/myrepo
[test@localhost helloworld]$ mkdir -p proto/helloworld/
[test@localhost helloworld]$ cat > proto/helloworld/helloworld.proto <<EOF
syntax = "proto3";
option go_package = "./;__";
package helloworld;

import "google/api/annotations.proto";

service Greeter {
  rpc SayHello (HelloRequest) returns (HelloReply) {
    option (google.api.http) = {			
          post: "/v1/example/echo"
          body: "*"
      };
    }
}
message HelloRequest {
  string name = 1;
} 
message HelloReply {
  string message = 1;
}
EOF
[test@localhost helloworld]$ mkdir -p proto/google/api && cp -r $(go env GOPATH)/src/github.com/grpc-ecosystem/grpc-gateway/third_party/googleapis/google/api/{annotations.proto,http.proto} proto/google/api
# 此时结构如下
[test@localhost helloworld]$ tree
.
├── go.mod
└── proto
    ├── google
    │   └── api
    │       ├── annotations.proto
    │       └── http.proto
    └── helloworld
        └── helloworld.proto

4 directories, 4 files
# 生成server stubs源码
[test@localhost helloworld]$ python3 -m grpc_tools.protoc -I./proto --python_out=./proto/ --grpc_python_out=./proto/ ./proto/helloworld/helloworld.proto

# 编写grpc服务端,main.py
[test@localhost helloworld]$ cat > main.py <<EOF
from concurrent import futures
import logging

import grpc
from proto.helloworld import helloworld_pb2
from proto.helloworld import helloworld_pb2_grpc

class Greeter(helloworld_pb2_grpc.GreeterServicer):

    def SayHello(self, request, context):
        return helloworld_pb2.HelloReply(message='Hello, %s!' % request.name)

def serve():
    server = grpc.server(futures.ThreadPoolExecutor(max_workers=10))
    helloworld_pb2_grpc.add_GreeterServicer_to_server(Greeter(), server)
    server.add_insecure_port('[::]:8080')
    server.start()
    server.wait_for_termination()

if __name__ == '__main__':
    logging.basicConfig()
    serve()
EOF

# 此时执行 python3 main.py 会报错;
[test@localhost helloworld]$ python3 main.py 
Traceback (most recent call last):
  File "main.py", line 6, in <module>
    from proto.helloworld import helloworld_pb2_grpc
  File "/home/test/helloworld/proto/helloworld/helloworld_pb2_grpc.py", line 5, in <module>
    from helloworld import helloworld_pb2 as helloworld_dot_helloworld__pb2
ModuleNotFoundError: No module named 'helloworld'
# 解决方法;
[test@localhost helloworld]$ sed -E -i 's/from helloworld /from . /g' /home/test/helloworld/proto/helloworld/helloworld_pb2_grpc.py
# grpc服务端，现在就可以使用python3 main.py运行了
# 此时的目录结构如下
[test@localhost helloworld]$ tree
.
├── main.py
└── proto
    ├── google
    │   └── api
    │       ├── annotations.proto
    │       └── http.proto
    └── helloworld
        ├── helloworld_pb2_grpc.py
        ├── helloworld_pb2.py
        ├── helloworld.proto
        └── __pycache__
            ├── helloworld_pb2.cpython-37.pyc
            └── helloworld_pb2_grpc.cpython-37.pyc

5 directories, 8 files

下面准备grpc-gateway

[test@localhost helloworld]$ mkdir -p ./gen/go
[test@localhost helloworld]$ go mod init github.com/test/myrepo
# 生成 gateway的相关源码
[test@localhost helloworld]$ python3 -m grpc_tools.protoc -I./proto --go_out ./gen/go/ --go-grpc_out ./gen/go/ ./proto/helloworld/helloworld.proto
[test@localhost helloworld]$ python3 -m grpc_tools.protoc -I ./proto --grpc-gateway_out=logtostderr=true:./gen/go ./proto/helloworld/helloworld.proto
[test@localhost helloworld]$ go mod tidy

# gateway 网关代码，8081监听8080
[test@localhost helloworld]$ cat > helloworld.gw.go <<EOF
package main
import (
    "flag"
    "fmt"
    "net/http"

    gw "github.com/test/myrepo/gen/go"

    "github.com/grpc-ecosystem/grpc-gateway/v2/runtime"
    "golang.org/x/net/context"
    "google.golang.org/grpc"
)
var (
    echoEndpoint = flag.String("echo_endpoint", "localhost:8080", "endpoint of YourService")
)
func run() error {
    ctx := context.Background()
    ctx, cancel := context.WithCancel(ctx)
    defer cancel()
    mux := runtime.NewServeMux()
    opts := []grpc.DialOption{grpc.WithInsecure()}
    err := gw.RegisterGreeterHandlerFromEndpoint(ctx, mux, *echoEndpoint, opts)
    if err != nil {
        return err
	}
    return http.ListenAndServe(":8081", mux)
}
func main() {
    if err := run(); err != nil {
        fmt.Print(err.Error())
    }
}
EOF
# 此时目录结构如下
[test@localhost helloworld]$ tree
.
├── gen
│   └── go
│       ├── helloworld_grpc.pb.go
│       ├── helloworld.pb.go
│       └── helloworld.pb.gw.go
├── go.mod
├── go.sum
├── helloworld.gw.go
├── main.py
└── proto
    ├── google
    │   └── api
    │       ├── annotations.proto
    │       └── http.proto
    └── helloworld
        ├── helloworld_pb2_grpc.py
        ├── helloworld_pb2.py
        ├── helloworld.proto
        └── __pycache__
            ├── helloworld_pb2.cpython-37.pyc
            └── helloworld_pb2_grpc.cpython-37.pyc

7 directories, 14 files
# 运行 grpc-gateway
[test@localhost helloworld]$ go run helloworld.gw.go

5.测试

# 首先运行
[test@localhost helloworld]$ python3 main.py
# 另开一终端执行
[test@localhost helloworld]$ go run helloworld.gw.go
# 另开一终端执行
[test@localhost helloworld]$ curl -X POST http://localhost:8081/v1/example/echo -d '{"name": "欧力给"}'
{"message":"Hello, 欧力给!"}
# 如果访问没有输出，请将curl 中的 localhost换成具体的IP地址

6.总结

之后，想必大家可以使用任何grpc支持的语言搭配grpc-gateway使用了吧，套路就是：

写出proto文件，并加以修改生成某语言对应的grpc stub源码生成gw go语言代码编写 grpc服务端编写 grpc 代理(go)