环境搭建

rust安装
编辑器 rust插件安装
环境变量配置
国内源配置

demo

需求

1 搭建服务，完成一个可以接受任何参数的post的方法
2 接入opensearch,将post收到的参数上传的opensearch
3 将该demo做成docker运行

步骤

1.使用cargo new xx --bin 创建新项目
2.编辑器打开新项目 在Cargo.toml引入需要的包

[dependencies]
 # rocket 接口相关
rocket = { version = "0.5.0", features = ["json"] }
 # serde json序列化反序列化
serde = { version = "1.0", features = ["derive"] }
 # opensearch 操作包
opensearch = { version = "2.0.0" }
 # tokio 异步线程包
tokio = { version = "1.24.2", features = ["full"] }
 # chrono 时间包
chrono = {version="0.4.23"}

3.编写代码

#[launch]
fn rocket() -> Rocket<Build> {
    let rt = Runtime::new().unwrap();
    let client = rt.block_on(init_open_search()).expect("Failed to initialize OpenSearch");
    rocket::build()
        .manage(client)
        .mount("/", routes![index])
        .mount("/data", routes![create])
}

async fn init_open_search() -> Result<OpenSearch, Box<dyn std::error::Error>> {
    let url = Url::parse("url")?;

    let conn_pool = SingleNodeConnectionPool::new(url);
    let transport = TransportBuilder::new(conn_pool)
        .auth(Credentials::Basic("username".parse().unwrap(), "passwrod.".parse().unwrap()))
        .build()?;
    let client = OpenSearch::new(transport);
    Ok(client)
}

#[get("/")]
fn index() -> &'static str {
    "Hello, world!"
}

#[post("/", format = "application/json", data = "<data>")]
async fn create(data: rocket::serde::json::Json<HashMap<String, Value>>, client: &State<OpenSearch>) -> String {
    let params = data.0;
    let _ = send_data(client, params.clone()).await;
    format!("Received data: {:?}", params)
}

async fn send_data(client: &State<OpenSearch>, data: HashMap<String, Value>) -> Result<(), Box<dyn std::error::Error>> {
    let log_data = LogData {
        timestamp: chrono::offset::Utc::now().timestamp(),
        data: data,
    };
    let response = client
        .index(IndexParts::Index("test_stream_rust"))
        .body(json!(log_data))
        .send().await.expect("Failed to add OpenSearch");
    println!("Successfully indexed a document {}", response.status_code());
    Ok(())
}


#[derive(Serialize, Deserialize)]
struct LogData {
    timestamp: i64,
    data: HashMap<String, Value>,
}

4.docker build

ARG RUST_VERSION=1.76
ARG APP_NAME=opensearch-service

################################################################################
# Create a stage for building the application.

FROM rust:${RUST_VERSION} AS build
ARG APP_NAME
RUN USER=root cargo new --bin ${APP_NAME}
WORKDIR /app

COPY ./src ./src
COPY ./Cargo.toml ./Cargo.toml
RUN cargo build --release
RUN cp /app/target/release/${APP_NAME} /app/target/release/server



FROM debian:stable-slim
RUN apt-get update && apt-get install -y libssl3 && rm -rf /var/lib/apt/lists/*
# Copy the executable from the "build" stage.
COPY --from=build /app/target/release/server /usr/local/bin/server

# Configure rocket to listen on all interfaces.
ENV ROCKET_ADDRESS=0.0.0.0

# Expose the port that the application listens on.
EXPOSE 8000

# What the container should run when it is started.
CMD ["/usr/local/bin/server"]

5.测试
5.1 启动服务

docker build -t opensearch-service .
winpty docker run -p 8000:8000 -it --rm opensearch-service

5.2 调用接口
postman测试

image.png

5.3 验证数据
opensearch查看对应indexs，看到内容成功插入

6.总结
6.1 关于cargo中的features
你引用的包里还引用了别人的包，但是默认是不自动引入这些配置了features的包（即可选引用包), 通过features可以把对应的包及功能引入
6.2 rocket中#[launch]可以在代码中不加入main方法
6.3 tikio异步转同步
opensearch的demo全是异步的，但是rocket使用同步，为了引入客户端，将异步转为同步

 let rt = Runtime::new().unwrap();
 let client = rt.block_on(init_open_search()).expect("Failed to initialize OpenSearch");

6.4 如何在rocket引入一个全局变量

 rocket::build() .manage(client)

此处manage引入后，所有的api方法中都可以通过参数拿到这个client
6.5 关于json序列化

#[derive(Serialize, Deserialize)]
struct LogData {
    timestamp: i64,
    data: HashMap<String, Value>,
}

此处的log data 中不要直接引入别人的包中的对象，可能无法直接序列化，尽量用基础类。
6.6 docker打包问题
一开始用用docker init 构建项目后 docker run直接报错找不到包。
排查方法
6.6.1 先注释掉 dockerfile中最后一句 "CMD ["/usr/local/bin/server"]"，再次运行，找到对应文件位置后发现打好的原生包是存在的，但是命令行运行还是报错找不到包
6.6.2 内核缺少依赖包
ldd filename 通过该命令发现内核缺少依赖包
为了解决这个问题，将运行环境从alpine切换为debian:stable-slim,发现还是缺少rocket依赖的openssl3的包
加入命令RUN apt-get update && apt-get install -y libssl3 && rm -rf /var/lib/apt/lists/*
成功打包运行