【实战】将 ASP.NET Core 打包成镜像 NUGET 超时问题

需求：将之前使用 ASP.NET Core 6.0 的项目打包成 Docker 镜像，然后在路由器（openwrt）上面运行，在执行打包成 docker 镜像的时候，在 dotnet restore 还原 nuget 包的时候会出现超时错误，如下图：

Determining projects to restore...
  Failed to download package 'SkiaSharp.2.80.3' from 'https://api.nuget.org/v3-flatcontainer/skiasharp/2.80.3/skiasharp.2.80.3.nupkg'.
  The download of 'https://api.nuget.org/v3-flatcontainer/skiasharp/2.80.3/skiasharp.2.80.3.nupkg' timed out because no data was received for 60000ms.
Exception of type 'System.TimeoutException' was thrown.
  Failed to download package 'SkiaSharp.NativeAssets.Linux.2.80.3' from 'https://api.nuget.org/v3-flatcontainer/skiasharp.nativeassets.linux/2.80.3/skiasharp.nativeassets.linux.2.80.3.nupkg'.
  The download of 'https://api.nuget.org/v3-flatcontainer/skiasharp.nativeassets.linux/2.80.3/skiasharp.nativeassets.linux.2.80.3.nupkg' timed out because no data was received for 60000ms.
Exception of type 'System.TimeoutException' was thrown.

项目 Dockerfile 默认配置如下：

#See https://aka.ms/containerfastmode to understand how Visual Studio uses this Dockerfile to build your images for faster debugging.

FROM mcr.microsoft.com/dotnet/aspnet:6.0 AS base
WORKDIR /app
EXPOSE 80
EXPOSE 443

FROM mcr.microsoft.com/dotnet/sdk:6.0 AS build
WORKDIR /src
COPY ["HomeCloud/HomeCloud.csproj", "HomeCloud/"]
RUN dotnet restore "HomeCloud/HomeCloud.csproj"
COPY . .
WORKDIR "/src/HomeCloud"
RUN dotnet build "HomeCloud.csproj" -c Release -o /app/build

FROM build AS publish
RUN dotnet publish "HomeCloud.csproj" -c Release -o /app/publish

FROM base AS final
WORKDIR /app
COPY --from=publish /app/publish .
ENTRYPOINT ["dotnet", "HomeCloud.dll"]

打包成 docker 镜像命令如下：

docker build -t itsvse_test:v1 -f /data/ddns/HomeCloud/Dockerfile .

通过搜索引擎发现其他用户也遇到类似的问题，链接：https://github.com/NuGet/Home/issues/10275

根据网友的回答，尝试增加 --disable-parallel 参数禁用并行，修改后如下：

RUN dotnet restore "HomeCloud/HomeCloud.csproj" --disable-parallel

现还是会出现 System.TimeoutException 超时的问题，突然灵机一动，既然是还原 nuget 包超时，为什么不能换个源呢？果断换成腾讯的 nuget 源，参考如下：

使用腾讯云 Nuget 包管理器加速下载
https://www.itsvse.com/thread-7875-1-1.html

nuget 国内源（镜像源）
https://www.itsvse.com/thread-3925-1-1.html

修改 Dockerfile 文件，移除默认的 nuget.org，新增腾讯云的源，如下：

RUN dotnet nuget remove source nuget.org
RUN dotnet nuget add source https://mirrors.cloud.tencent.com/nuget/ -n tencent_nuget
RUN dotnet restore "HomeCloud/HomeCloud.csproj"

最后，成功打包成 docker 镜像，在还原 nuget 包耗时 22 秒，没有出现超时问题，如下图：