Dubbo Rust 近期發布了首個正式版本，Dubbo Rust 目標是對齊 Dubbo 3 的所有核心功能設計，包括基于 HTTP/2 的高性能通信、用戶友好的微服務開發編程模式、通過接入Dubbo Mesh提供豐富的服務治理能力等。相比于其他語言實現，Dubbo Rust 將很好的利用 Rust 語言極致性能、安全和指令級掌控能力的特點。

1?

前置條件

安裝 Rust 開發環境

安裝 protoc 工具

2?

使用 IDL 定義 Dubbo 服務

Greeter 服務定義如下，包含一個 Unary（Request - Response）模型的 Dubbo 服務。

// ./proto/greeter.proto
syntax = "proto3";


option java_multiple_files = true;


package org.apache.dubbo.sample.tri;


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


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


service Greeter{
  // unary
  rpc greet(GreeterRequest) returns (GreeterReply);
}

3?

添加 Dubbo-Rust 及相關依賴到項目

# ./Cargo.toml
[package]
name = "example-greeter"
version = "0.1.0"
edition = "2021"


[[bin]]
name = "greeter-server"
path = "src/greeter/server.rs"


[[bin]]
name = "greeter-client"
path = "src/greeter/client.rs"


[dependencies]
http = "0.2"
http-body = "0.4.4"
futures-util = {version = "0.3", default-features = false}
tokio = { version = "1.0", features = [ "rt-multi-thread", "time", "fs", "macros", "net", "signal"] }
prost-derive = {version = "0.10", optional = true}
prost = "0.10.4"
async-trait = "0.1.56"
tokio-stream = "0.1"


dubbo = "0.2.0"
dubbo-config = "0.2.0"


[build-dependencies]
dubbo-build = "0.2.0"

4?

配置 Dubbo - Build 編譯 IDL

在項目根目錄創建（注意不是 src 目錄），創建 build.rs 文件并添加以下內容：

// ./build.rs
fn main() {
    dubbo_build::configure()
        .compile(&["proto/greeter.proto"], &["proto/"])
        .unwrap();
}

這樣配置之后，編譯項目就可以生成 Dubbo Stub 相關代碼。

路徑一般在：

./target/debug/build/example-greeter/out/org.apache.dubbo.sample.tri.rs

5?

編寫 Dubbo 業務代碼

5.1

編寫 Dubbo Server

// ./src/greeter/server.rs
use ...


#[tokio::main]
async fn main() {
    register_server(GreeterServerImpl {
        name: "greeter".to_string(),
    });


    // Dubbo::new().start().await;
    Dubbo::new()
        .with_config({
            let r = RootConfig::new();
            match r.load() {
                Ok(config) => config,
                Err(_err) => panic!("err: {:?}", _err), // response was droped
            }
        })
        .start()
        .await;
}


#[allow(dead_code)]
#[derive(Default, Clone)]
struct GreeterServerImpl {
    name: String,
}


// #[async_trait]
#[async_trait]
impl Greeter for GreeterServerImpl {
    async fn greet(
        &self,
        request: Request,
    ) -> Result, dubbo::Status> {
        println!("GreeterServer::greet {:?}", request.metadata);


        Ok(Response::new(GreeterReply {
            message: "hello, dubbo-rust".to_string(),
        }))
    }
}

5.2

配置 dubbo.yaml

dubbo.yaml 指示 Server 端的配置，包括暴露的服務列表、協議配置、監聽配置等。

# ./dubbo.yaml
name: dubbo
service:
  org.apache.dubbo.sample.tri.Greeter:
    version: 1.0.0
    group: test
    protocol: triple
    registry: ''
    serializer: json
    protocol_configs:
      triple:
        ip: 0.0.0.0
        port: '8888'
        name: triple
protocols:
  triple:
    ip: 0.0.0.0
    port: '8888'
    name: triple

5.3

編寫 Dubbo Client

// ./src/greeter/client.rs
use ...


#[tokio::main]
async fn main() {
    let mut cli = GreeterClient::new().with_uri("http://127.0.0.1:8888".to_string());


    println!("# unary call");
    let resp = cli
        .greet(Request::new(GreeterRequest {
            name: "message from client".to_string(),
        }))
        .await;
    let resp = match resp {
        Ok(resp) => resp,
        Err(err) => return println!("{:?}", err),
    };
    let (_parts, body) = resp.into_parts();
    println!("Response: {:?}", body);
}

6?

運行并總結

6.1

編譯

執行 cargo build 來編譯 Server 和 Client。

6.2

運行 Server

執行 ./target/debug/greeter-server 來運行 Server，如上文 dubbo.yaml 所配置，Server 會監聽 8888 端口，并以 triple 協議提供 RPC 服務。

$ ./target/debug/greeter-server
2022-09-28T2328.104577Z  INFO dubbo: url: Some(Url { uri: "triple://0.0.0.0:8888/org.apache.dubbo.sample.tri.Greeter", protocol: "triple", location: "0.0.0.0:8888", ip: "0.0.0.0", port: "8888", service_key: ["org.apache.dubbo.sample.tri.Greeter"], params: {} })

6.3

運行 Client，驗證調用是否成功

執行 ./target/debug/greeter-client 來運行 Client，調用triple://127.0.0.1:8888/org.apache.dubbo.sample.tri.Greeter 下的各種方法。

$ ./target/debug/greeter-client
Response: GreeterReply { message: "hello, dubbo-rust" }

審核編輯：劉清