创建自定义插件

2025-02-05

本文介绍如何为开发代理创建自定义插件。通过为开发代理创建插件，可以扩展其功能并添加自定义功能以满足你的需求。

先决条件

在开始创建自定义插件之前，请确保满足以下先决条件：

.NET Core SDK
可在开发代理 GitHub 发布页上找到的最新版本的开发代理抽象 DLL

创建新插件

按照后续步骤创建新项目：

使用 dotnet new classlib 命令创建新的类库项目。
```
dotnet new classlib -n MyCustomPlugin
```
在 Visual Studio Code 中打开新创建的项目。
```
code MyCustomPlugin
```
将开发代理抽象 DLL （dev-proxy-abstractions.dll）添加到项目文件夹。

添加作为 dev-proxy-abstractions.dll 对项目 DevProxyCustomPlugin.csproj 文件的引用。

<ItemGroup>
  <Reference Include="dev-proxy-abstractions">
    <HintPath>.\dev-proxy-abstractions.dll</HintPath>
    <Private>false</Private>
    <ExcludeAssets>runtime</ExcludeAssets>
  </Reference>
</ItemGroup>

添加项目所需的 NuGet 包。

dotnet add package Microsoft.Extensions.Configuration
dotnet add package Microsoft.Extensions.Configuration.Binder
dotnet add package Microsoft.Extensions.Logging.Abstractions
dotnet add package Unobtanium.Web.Proxy

通过在文件中添加标记 ExcludeAssetsPackageReferenceDevProxyCustomPlugin.csproj ，从生成输出中排除依赖项 DLL。
```
<ExcludeAssets>runtime</ExcludeAssets>
```

创建实现 BaseProxyPlugin 接口的新类。

using Microsoft.DevProxy.Abstractions;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.Logging;

namespace MyCustomPlugin;

public class CatchApiCalls(IPluginEvents pluginEvents, IProxyContext context, ILogger logger, ISet<UrlToWatch> UrlsToWatch, IConfigurationSection? configSection = null) : BaseProxyPlugin(pluginEvents, context, logger, UrlsToWatch, configSection)
{
  public override string Name => nameof(CatchApiCalls);

  public override async Task RegisterAsync()
  {
    await base.RegisterAsync();

    PluginEvents.BeforeRequest += BeforeRequestAsync;
  }

  private Task BeforeRequestAsync(object sender, ProxyRequestArgs e)
  {
    if (UrlsToWatch is null ||
      !e.HasRequestUrlMatch(UrlsToWatch))
    {
      // No match for the URL, so we don't need to do anything
      Logger.LogRequest("URL not matched", MessageType.Skipped, new LoggingContext(e.Session));
      return Task.CompletedTask;
    }

    var headers = e.Session.HttpClient.Request.Headers;
    var header = headers.Where(h => h.Name == "Authorization").FirstOrDefault();
    if (header is null)
    {
      Logger.LogRequest($"Does not contain the Authorization header", MessageType.Warning, new LoggingContext(e.Session));
      return Task.CompletedTask;
    }

    return Task.CompletedTask;
  }
}

生成项目。
```
dotnet build
```

使用自定义插件

若要使用自定义插件，需要将其添加到开发代理配置文件：

在文件中添加新插件配置 devproxyrc.json 。

{
  "plugins": [{
    "name": "CatchApiCalls",
    "enabled": true,
    "pluginPath": "./bin/Debug/net8.0/MyCustomPlugin.dll",
  }]
}

运行开发代理。
```
devproxy
```

示例插件检查所需授权标头的所有匹配 URL。如果标头不存在，则会显示警告消息。

将自定义配置添加到插件（可选）

可以通过添加自定义配置来扩展插件的逻辑：

_configuration添加新对象并在方法中Register绑定它。

using Microsoft.DevProxy.Abstractions;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.Logging;

namespace MyCustomPlugin;

public class CatchApiCallsConfiguration
{
  public string? RequiredHeader { get; set; }
}

public class CatchApiCalls(IPluginEvents pluginEvents, IProxyContext context, ILogger logger, ISet<UrlToWatch> UrlsToWatch, IConfigurationSection? configSection = null) : BaseProxyPlugin(pluginEvents, context, logger, UrlsToWatch, configSection)
{
  public override string Name => nameof(CatchApiCalls);

  // Define you custom configuration
  private readonly CatchApiCallsConfiguration _configuration = new();

  public override async Task RegisterAsync()
  {
    await base.RegisterAsync();

    // Bind your plugin configuration
    configSection?.Bind(_configuration);

    // Register your event handlers
    PluginEvents.BeforeRequest += BeforeRequestAsync;
  }

  private Task BeforeRequestAsync(object sender, ProxyRequestArgs e)
  {
    if (UrlsToWatch is null ||
      !e.HasRequestUrlMatch(UrlsToWatch))
    {
      // No match for the URL, so we don't need to do anything
      Logger.LogRequest("URL not matched", MessageType.Skipped, new LoggingContext(e.Session));
      return Task.CompletedTask;
    }

    // Start using your custom configuration
    var requiredHeader = _configuration?.RequiredHeader ?? string.Empty;
    if (string.IsNullOrEmpty(requiredHeader))
    {
      // Required header is not set, so we don't need to do anything
      Logger.LogRequest("Required header not set", MessageType.Skipped, new LoggingContext(e.Session));
      return Task.CompletedTask;
    }

    var headers = e.Session.HttpClient.Request.Headers;
    var header = headers.Where(h => h.Name == requiredHeader).FirstOrDefault();
    if (header is null)
    {
      Logger.LogRequest($"Does not contain the {requiredHeader} header", MessageType.Warning, new LoggingContext(e.Session));
      return Task.CompletedTask;
    }

    return Task.CompletedTask;
  }
}

生成项目。
```
dotnet build
```

devproxyrc.json更新文件以包含新配置。

{
  "plugins": [{
    "name": "CatchApiCalls",
    "enabled": true,
    "pluginPath": "./bin/Debug/net8.0/MyCustomPlugin.dll",
    "configSection": "catchApiCalls"
  }],
  "catchApiCalls": {
    "requiredHeader": "Authorization" // Example configuration
  }
}

运行开发代理。
```
devproxy
```

通过

创建自定义插件

先决条件

创建新插件

使用自定义插件

将自定义配置添加到插件（可选）

其他资源