Rust结构化日志库slog-bunyan的使用

slog-bunyan是一个为Rust应用提供Bunyan格式JSON日志记录功能的库，基于slog-json构建，会输出符合Bunyan定义的JSON日志字段。

安装

在项目目录中运行以下Cargo命令：

cargo add slog-bunyan

或者在Cargo.toml中添加：

slog-bunyan = "2.5.0"

使用示例

下面是一个完整的slog-bunyan使用示例：

use slog::{info, o, Drain, Logger};
use slog_bunyan::default;
use std::sync::Mutex;

fn main() {
    // 创建Bunyan格式的日志drain
    let drain = default(std::io::stdout());
    
    // 使用Mutex包装drain以支持线程安全
    let drain = Mutex::new(drain).fuse();
    
    // 创建根logger
    let root_logger = Logger::root(drain, o!("version" => "1.0.0"));
    
    // 创建子logger，添加更多上下文信息
    let log = root_logger.new(o!("component" => "main"));
    
    // 记录结构化日志
    info!(log, "Application started"; 
        "pid" => std::process::id(),
        "config" => "production",
        "thread_count" => 4
    );
    
    // 记录错误日志
    info!(log, "Processing request"; 
        "method" => "GET",
        "path" => "/api/users",
        "status" => 200,
        "duration_ms" => 42
    );
}

输出示例

上面的代码会产生类似这样的JSON格式日志：

{
  "name": "your-app",
  "hostname": "your-host",
  "pid": 12345,
  "level": 30,
  "msg": "Application started",
  "time": "2024-01-05T12:34:56.789Z",
  "v": 0,
  "version": "1.0.0",
  "component": "main",
  "config": "production",
  "thread_count": 4
}

主要特性

• 输出符合Bunyan日志格式的JSON
• 支持结构化日志记录
• 线程安全
• 可与其他slog drain组合使用
• 支持自定义字段和上下文

slog-bunyan是构建生产级Rust应用程序日志系统的理想选择，特别是需要与现有Bunyan日志处理工具集成时。

完整示例代码

下面是一个更完整的slog-bunyan使用示例，包含了不同日志级别和自定义配置：

use slog::{debug, error, info, warn, o, Drain, Logger};
use slog_bunyan::{default, with_name};
use std::sync::Mutex;

fn main() {
    // 创建自定义名称的Bunyan logger
    let drain = with_name("my-rust-app", std::io::stdout());
    
    // 使用Mutex包装drain以支持线程安全
    let drain = Mutex::new(drain.fuse());
    
    // 创建根logger并添加全局字段
    let root_logger = Logger::root(
        drain,
        o!(
            "version" => env!("CARGO_PKG_VERSION"),
            "environment" => "production",
            "service" => "api-server"
        )
    );
    
    // 创建子logger用于特定模块
    let http_log = root_logger.new(o!("component" => "http"));
    let db_log = root_logger.new(o!("component" => "database"));
    
    // 记录不同级别的日志
    debug!(http_log, "Debug message"; "detail" => "verbose info");
    info!(http_log, "HTTP request received";
        "method" => "POST",
        "path" => "/users",
        "client_ip" => "192.168.1.1"
    );
    
    warn!(db_log, "Slow query detected";
        "query" => "SELECT * FROM users",
        "duration_ms" => 256
    );
    
    error!(root_logger, "Critical error occurred";
        "error" => "Connection timeout",
        "retry_count" => 3,
        "backtrace" => "..."
    );
    
    // 记录带有嵌套结构的日志
    info!(root_logger, "Application metrics";
        "metrics" => {
            "cpu_usage" => 42.5,
            "memory_mb" => 128,
            "active_connections" => 24
        }
    );
}

完整输出示例

[
  {
    "name": "my-rust-app",
    "hostname": "your-host",
    "pid": 12345,
    "level": 20,
    "msg": "Debug message",
    "time": "2024-01-05T12:34:56.789Z",
    "v": 0,
    "version": "1.0.0",
    "environment": "production",
    "service": "api-server",
    "component": "http",
    "detail": "verbose info"
  },
  {
    "name": "my-rust-app",
    "hostname": "your-host",
    "pid": 12345,
    "level": 30,
    "msg": "HTTP request received",
    "time": "2024-01-05T12:34:56.790Z",
    "v": 0,
    "version": "1.0.0",
    "environment": "production",
    "service": "api-server",
    "component": "http",
    "method": "POST",
    "path": "/users",
    "client_ip": "192.168.1.1"
  },
  {
    "name": "my-rust-app",
    "hostname": "your-host",
    "pid": 12345,
    "level": 40,
    "msg": "Slow query detected",
    "time": "2024-01-05T12:34:56.791Z",
    "v": 0,
    "version": "1.0.0",
    "environment": "production",
    "service": "api-server",
    "component": "database",
    "query": "SELECT * FROM users",
    "duration_ms": 256
  },
  {
    "name": "my-rust-app",
    "hostname": "your-host",
    "pid": 12345,
    "level": 50,
    "msg": "Critical error occurred",
    "time": "2024-01-05T12:34:56.792Z",
    "v": 0,
    "version": "1.0.0",
    "environment": "production",
    "service": "api-server",
    "error": "Connection timeout",
    "retry_count": 3,
    "backtrace": "..."
  },
  {
    "name": "my-rust-app",
    "hostname": "your-host",
    "pid": 12345,
    "level": 30,
    "msg": "Application metrics",
    "time": "2024-01-05T12:34:56.793Z",
    "v": 0,
    "version": "1.0.0",
    "environment": "production",
    "service": "api-server",
    "metrics": {
      "cpu_usage": 42.5,
      "memory_mb": 128,
      "active_connections": 24
    }
  }
]