c# - 连接 NLog 并将其注入(inject) .NET Core 控制台应用程序

Question

我创建了一个消费者/工作，我将在 Linux 上以 C# 编写的进程运行。

该过程将:

1. 从 RabbitMQ 读取消息
2. 修改数据库
3. 记录任何错误

NLog 上所有关于 .NET Core 的文档都在 ASP.NET Core 上。当我尝试获取 ILogger 实现时，它返回 null。

这里是接线和使用的异常(exception)情况:

static void ConfigureServices()
{
    string environment = Environment.GetEnvironmentVariable("ASPNETCORE_ENVIRONMENT");

    var builder = new ConfigurationBuilder()
         .SetBasePath(Path.Combine(AppContext.BaseDirectory))
         .AddJsonFile("appsettings.json", optional: true, reloadOnChange: true)
         .AddJsonFile($"appsettings.{environment}.json", optional: true);

    var services = new ServiceCollection();

    Configuration = builder.Build();

    [...]

    services.AddLogging();

    ServiceProvider = services.BuildServiceProvider();

    var loggerFactory = ServiceProvider.GetService<ILoggerFactory>();
    loggerFactory.AddNLog();
}

static void Main(string[] args)
{
    ConfigureServices();
    
    var logger = ServiceProvider.GetService<NLog.ILogger>();

    logger.Debug("Logging");

    [...]
}

不要与环境变量ASPNETCORE_ENVIRONMENT混淆；它仅用于确定要使用的 appsettings.json。

我的代码基于这个 issue report .

最后，这些是我目前已经安装的包。

<ItemGroup>
  <PackageReference Include="Microsoft.EntityFrameworkCore" Version="1.1.2" />
  <PackageReference Include="Microsoft.Extensions.Configuration" Version="1.1.2" />
  <PackageReference Include="Microsoft.Extensions.Configuration.Abstractions" Version="1.1.2" />
  <PackageReference Include="Microsoft.Extensions.Configuration.EnvironmentVariables" Version="1.1.2" />
  <PackageReference Include="Microsoft.Extensions.Configuration.Json" Version="1.1.2" />
  <PackageReference Include="Microsoft.Extensions.Options.ConfigurationExtensions" Version="1.1.2" />
  <PackageReference Include="NLog" Version="5.0.0-beta09" />
  <PackageReference Include="NLog.Extensions.Logging" Version="1.0.0-rtm-beta5" />
  <PackageReference Include="Npgsql" Version="3.2.4.1" />
  <PackageReference Include="Npgsql.EntityFrameworkCore.PostgreSQL" Version="1.1.0" />
</ItemGroup>

Answer 1

.NET Core 1 控制台应用程序中 NLog 的完整简约示例(基于 NLog.Extensions.Logging 存储库):

var services = new ServiceCollection();
services.AddLogging();
var provider = services.BuildServiceProvider();

var factory = provider.GetService<ILoggerFactory>();
factory.AddNLog();
factory.ConfigureNLog("nlog.config");

var logger = provider.GetService<ILogger<Program>>();
logger.LogCritical("hello nlog");

引用资料:

    <ItemGroup>
        <PackageReference Include="NLog.Extensions.Logging" Version="1.0.0-rtm-beta5" />
        <PackageReference Include="Microsoft.Extensions.Configuration" Version="1.1.2" />
        <PackageReference Include="Microsoft.Extensions.DependencyInjection" Version="1.1.1" />
        <PackageReference Include="Microsoft.Extensions.Logging" Version="1.1.2" />
    </ItemGroup>

nlog.config:

<?xml version="1.0" encoding="utf-8" ?>
<nlog xmlns="http://www.nlog-project.org/schemas/NLog.xsd"
      xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
      internalLogFile="internal-nlog.txt">

  <variable name="Layout"
            value="${longdate}|${level:uppercase=true}|${logger}|${message}"/>

  <!-- the targets to write to -->
  <targets>
    <!-- write logs to file -->
    <target xsi:type="File" 
            name="allfile" 
            fileName="nlog-all-${shortdate}.log"
            layout="${Layout}" />

    <!-- write to the void aka just remove -->
    <target xsi:type="Null" name="blackhole" />
  </targets>

  <!-- rules to map from logger name to target -->
  <rules>
    <!--All logs, including from Microsoft-->
    <logger name="*" minlevel="Trace" writeTo="allfile" />

    <!--Skip Microsoft logs and so log only own logs-->
    <logger name="Microsoft.*" minlevel="Trace" writeTo="blackhole" final="true" />
  </rules>
</nlog>