C# 中使用 MassTransit

在生产环境中使用 MassTransit 时，通常需要进行详细的配置，包括设置连接字符串、配置队列、配置消费者、处理重试和错误队列等。以下是一个完整的示例，展示了如何在 ASP.NET Core 应用程序中配置 MassTransit，包括请求/响应模式和事件模式，并使用依赖注入。

1. 安装必要的 NuGet 包

首先，确保安装了以下 NuGet 包：

• MassTransit
• MassTransit.RabbitMQ
• MassTransit.AspNetCore
• MassTransit.ExtensionsDependencyInjection
• Microsoft.Extensions.Hosting

web端服务代码

<Project Sdk="Microsoft.NET.Sdk.Web"><PropertyGroup><TargetFramework>net6.0</TargetFramework><Nullable>enable</Nullable><ImplicitUsings>enable</ImplicitUsings></PropertyGroup><ItemGroup><PackageReference Include="MassTransit.Extensions.DependencyInjection" Version="7.3.1" /><PackageReference Include="MassTransit.Redis" Version="8.3.4" /><PackageReference Include="Swashbuckle.AspNetCore" Version="7.2.0" /><PackageReference Include="MassTransit.RabbitMQ" Version="8.3.4" /></ItemGroup><ItemGroup><ProjectReference Include="..\AppDto\AppDto.csproj" /></ItemGroup></Project>

using Microsoft.OpenApi.Models;
using MassTransit;
using WebApp_MssTransit.Filters;var builder = WebApplication.CreateBuilder(args);// Add services to the container.
builder.Services.AddMvc(opt =>
{opt.Filters.Add<ExceptionFilter>();
});
builder.Services.AddSwaggerGen(c =>
{c.SwaggerDoc("v1", new OpenApiInfo { Title = "My API", Version = "v1" });
});builder.Services.AddMassTransit(x =>
{// 使用内存//x.UsingInMemory();// 使用RabbitMqx.UsingRabbitMq((context, config) =>{config.Host("rabbitmq://localhost:5672", host =>{host.Username("admin");host.Password("admin");});});
});var app = builder.Build();// Configure the HTTP request pipeline.app.UseHttpsRedirection();
app.UseRouting();app.UseSwagger();
app.UseSwaggerUI(c => c.SwaggerEndpoint("v1/swagger.json", "My API V1"));app.UseEndpoints(endpoints =>
{endpoints.MapControllers();
});app.Run();

控制器里面

using AppDto;
using MassTransit;
using Microsoft.AspNetCore.Mvc;
using System.Text.Json;
using System.Text.Json.Serialization;namespace WebApp_MssTransit.Controllers;[ApiController]
[Route("[controller]")]
public class PublishController : ControllerBase
{private readonly ILogger<PublishController> _logger;private readonly IBus _bus;public PublishController(ILogger<PublishController> logger, IBus bus){_logger = logger;_bus = bus;}[HttpPost(template : nameof(PublishAsync))]public async Task PublishAsync(){var msg = new OrderMessage(){Id = Guid.NewGuid(),Name = "Phone",CreationTime = DateTime.Now};await _bus.Publish(msg);_logger.LogInformation($"Publish message :{JsonSerializer.Serialize(msg)}");}[HttpPost(template: nameof(SendAsync))]public async Task SendAsync(){var msg = new OrderMessage(){Id = Guid.NewGuid(),Name = "Phone",CreationTime = DateTime.Now};await _bus.Send(msg);_logger.LogInformation($"Send message :{JsonSerializer.Serialize(msg)}");}[HttpPost(template: nameof(RequestAirAsync))]public async Task<AirResponse> RequestAirAsync(){var airRequest = new AirRequest{CreationTime = DateTime.Now,Identity = DateTime.Now.Ticks};var esp = await _bus.Request<AirRequest, AirResponse>(airRequest);_logger.LogInformation($"{DateTime.Now.ToStringTime()} Request Response :{JsonSerializer.Serialize(esp)}");var espMsg = esp.Message;_logger.LogInformation($"{espMsg.CreationTime.ToStringTime()} Request Response data");return espMsg;}
}

信息公共类型，这里没有定义接口，直接共享AppDto

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;namespace AppDto;public class AirRequest
{public long Identity { get; set; }public DateTime CreationTime { get; set; }
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;namespace AppDto;public class AirResponse
{public long Identity { get; set; }public DateTime CreationTime { get; set; }
}

namespace AppDto;public class OrderMessage
{public Guid Id { get; init; }public string Name { get; set; }public DateTime CreationTime { get; set; }
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;namespace AppDto;public static class DateTimeExtant
{public static string ToStringTime(this DateTime time){return time.ToString("yyyy-MM-dd HH:mm:ss.fffff");}
}

接收消息处理端

<Project Sdk="Microsoft.NET.Sdk"><PropertyGroup><OutputType>Exe</OutputType><TargetFramework>net6.0</TargetFramework><ImplicitUsings>enable</ImplicitUsings><Nullable>enable</Nullable></PropertyGroup><ItemGroup><PackageReference Include="MassTransit.Extensions.DependencyInjection" Version="7.3.1" /><PackageReference Include="MassTransit.RabbitMQ" Version="8.3.4" /><PackageReference Include="MassTransit.Redis" Version="8.3.4" /><PackageReference Include="Microsoft.Extensions.Hosting" Version="6.0.1" /></ItemGroup><ItemGroup><ProjectReference Include="..\AppDto\AppDto.csproj" /></ItemGroup></Project>

using MassTransit;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
using MassTransit.RedisIntegration;
using ConsoleApp_Producer;
using MassTransit.Metadata;
using MassTransit.Util;
using System.Reflection;
using MassTransit.Internals;
using AppDto;
using ConsoleApp_consumer;Console.WriteLine("Hello, World!");var builder = Microsoft.Extensions.Hosting.Host.CreateDefaultBuilder(args);builder.ConfigureServices((hostContext, services) =>{services.AddMassTransit(x =>{// 通过扫描程序集注册消费者//x.AddConsumers(typeof(OrderConsumer).Assembly);// 通过类型单个注册消费者x.AddConsumer<OrderConsumer>();x.AddConsumer<AirHandle>();//x.SetKebabCaseEndpointNameFormatter();// 通过泛型单个注册消费者//x.AddConsumer<OrderEtoConsumer, OrderEtoConsumerDefinition>();// 通过指定命名空间注册消费者// x.AddConsumersFromNamespaceContaining<OrderEtoConsumer>();// 使用内存队列// x.UsingInMemory();x.UsingRabbitMq((context, config) =>{config.Host("rabbitmq://localhost:5672", hostconfig =>{hostconfig.Username("admin");hostconfig.Password("admin");});config.ConfigureEndpoints(context);});});});var host = builder.Build();
host.Run();

using AppDto;
using MassTransit;
using Microsoft.Extensions.Logging;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Text.Json;
using System.Threading.Tasks;namespace ConsoleApp_Producer;public class OrderConsumer : IConsumer<OrderMessage>
{private readonly ILogger<OrderConsumer> _logger;public OrderConsumer(ILogger<OrderConsumer> logger){_logger = logger;}public Task Consume(ConsumeContext<OrderMessage> context){_logger.LogInformation($"{DateTime.Now.ToStringTime()}收到消息:{JsonSerializer.Serialize(context.Message)},\n\t{context.Message.CreationTime.ToStringTime()} 消息时间");return Task.CompletedTask;}
}

using AppDto;
using ConsoleApp_Producer;
using MassTransit;
using Microsoft.Extensions.Logging;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;namespace ConsoleApp_consumer;public class AirHandle : IConsumer<AirRequest>
{private readonly ILogger<AirHandle> _logger;public AirHandle(ILogger<AirHandle> logger){_logger = logger;}public async Task Consume(ConsumeContext<AirRequest> context){_logger.LogInformation($"{DateTime.Now.ToStringTime()}Receive Data :{context.Message.Identity}");_logger.LogInformation($"{context.Message.CreationTime.ToStringTime()} message data");var resp = new AirResponse{Identity = context.Message.Identity,CreationTime = DateTime.Now,};await context.RespondAsync(resp);_logger.LogInformation($"{DateTime.Now.ToStringTime()} Respond  Data {resp}");}
}

7. 运行应用程序

运行应用程序后，你可以通过发送 HTTP 请求来发布消息和发送请求。例如，使用 Postman 或 cURL：

• 发布消息：

### 8. 处理错误和重试

在生产环境中，处理错误和重试是很重要的。你可以在 MassTransit 配置中启用重试和死信队列：

x.UseInMemoryOutbox();
x.UseMessageRetry(r => r.Interval(3, TimeSpan.FromSeconds(10)));
x.UseDelayedRedelivery(r => r.Intervals(TimeSpan.FromSeconds(10), TimeSpan.FromSeconds(30)));
x.UseFault tolerantExceptionStrategies();

9. 监控和日志

为了监控和调试，可以配置日志记录和监控工具。MassTransit 支持多种日志记录框架，如 Serilog 或 NLog。

10. 安全性和认证

在生产环境中，确保 RabbitMQ 连接是安全的，使用合适的认证和授权机制。可以配置 TLS 和其他安全选项。

通过以上步骤，你可以在生产环境中配置和使用 MassTransit，实现请求/响应和事件处理模式，并利用依赖注入进行服务管理和生命周期管理。