elixir grpc 试用

备注：

 elixir  grpc 封装测试
 
1.  安装
a. 安装 protoc 参考相关文档，比较简单
b. 安装elixir  grpc 插件 protoc-gen-elixir 同时配置环境变量
 
2. 基本项目使用
a. 创建项目
mix new appdemo

cd appdemo

touch helloword.proto

syntax = "proto3";

option java_multiple_files = true;
option java_package = "io.grpc.examples.helloworld";
option java_outer_classname = "HelloWorldProto";
option objc_class_prefix = "HLW";

package helloworld;

// The greeting service definition.
service Greeter {
  // Sends a greeting
  rpc SayHello (HelloRequest) returns (HelloReply) {}
}

// The request message containing the user's name.
message HelloRequest {
  string name = 1;
}

// The response message containing the greetings
message HelloReply {
  string message = 1;
}


项目结构如下：

├── README.md
├── config
│   └── config.exs
├── helloword.proto
├── lib
│   ├── appdemo.ex
├── mix.exs
└── test
    ├── appdemo_test.exs
    └── test_helper.exs

b. 生成代码

protoc --elixir_out=./lib helloword.proto
protoc -I . --elixir_out=plugins=grpc:./lib/ helloword.proto
结果如下：

├── README.md
├── config
│   └── config.exs
├── helloword.proto
├── lib
│   ├── appdemo.ex
│   └── helloword.pb.ex
├── mix.exs
└── test
    ├── appdemo_test.exs
    └── test_helper.exs

内容：

defmodule Helloworld.HelloRequest do
  use Protobuf

  @type t :: %__MODULE__{
          name: String.t()
        }
  defstruct [:name]

  field :name, 1, optional: true, type: :string
end

defmodule Helloworld.HelloReply do
  use Protobuf

  @type t :: %__MODULE__{
          message: String.t()
        }
  defstruct [:message]

  field :message, 1, optional: true, type: :string
end

defmodule Helloworld.Greeter.Service do
  use GRPC.Service, name: "helloworld.Greeter"

  rpc :SayHello, Helloworld.HelloRequest, Helloworld.HelloReply
end

defmodule Helloworld.Greeter.Stub do
  use GRPC.Stub, service: Helloworld.Greeter.Service
end
 
 
3. 项目使用（接上面项目）
a.  server端实现代码

lib/server.ex

defmodule Helloworld.Greeter.Server do
  use GRPC.Server, service: Helloworld.Greeter.Service

  @spec say_hello(Helloworld.HelloRequest.t(), GRPC.Server.Stream.t()) ::
          Helloworld.HelloReply.t()
  def say_hello(request, _stream) do
    Helloworld.HelloReply.new(message: "Hello #{request.name}")
  end
end


b. 项目使用opt 进行运行，具体来说是supervisor

lib/helloworld_app.ex
    
defmodule HelloworldApp do
  use Application

  def start(_type, _args) do
    import Supervisor.Spec

    children = [
      supervisor(GRPC.Server.Supervisor, [{Helloworld.Greeter.Server, 50051}])
    ]

    opts = [strategy: :one_for_one, name: HelloworldApp]
    Supervisor.start_link(children, opts)
  end
end

c. mix.exs 启动配置

def application do
    [mod: {HelloworldApp, []},
     applications: [:logger, :grpc]]
end
  
defp deps do
    [
      {:grpc, github: "tony612/grpc-elixir"},
      {:dialyxir, "~> 0.5", only: [:dev, :test], runtime: false},
    ]
end

d. config/config.exs

use Mix.Config

# Start server in OTP
config :grpc, start_server: true
 
 
4. 启动
mix  deps.get,compile 
iex -S  mix
 
5. golang client demo 
 
参考 https://github.com/rongfengliang/grpc-elixir
 
 
6. 参考资料
https://github.com/rongfengliang/grpc-elixir
https://github.com/rongfengliang/gprc-elixir-server
https://github.com/tony612/grpc-elixir
 
 
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