Google App Engine-运行具有特定Linux版本的docker映像

Question

我是Google App Engine的新成员，并试图将我的ASP.Net Core 3.1 Blazor网站部署到Google App Engine。我在Docker上使用了自定义版本，因为App Engine尚不支持.Net Core 3.1：

App.yaml

runtime: custom
env: flex

Dockerfile＃由Visual Studio生成]

FROM mcr.microsoft.com/dotnet/core/aspnet:3.1.3-bionic AS base
WORKDIR /app
EXPOSE 8080
EXPOSE 443

FROM mcr.microsoft.com/dotnet/core/sdk:3.1.201-bionic AS build
WORKDIR /src
COPY ["Blazor_SqLite_Publish/Blazor_SqLite_Publish.csproj", "Blazor_SqLite_Publish/"]
RUN dotnet restore "Blazor_SqLite_Publish/Blazor_SqLite_Publish.csproj"
COPY . .
WORKDIR "/src/Blazor_SqLite_Publish"
RUN dotnet build "Blazor_SqLite_Publish.csproj" -c Release -o /app/build

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

FROM base AS final
WORKDIR /app
COPY --from=publish /app/publish .
ENTRYPOINT ["dotnet", "Blazor_SqLite_Publish.dll"]
该网站已成功部署，甚至可以正常工作。但是我注意到，该App Engine实例在Ubuntu-16.04.6 LTS上运行我的docker映像：

root@xxxxxxxxxxx:/app# cat /etc/os-release
NAME="Ubuntu"
VERSION="16.04.6 LTS (Xenial Xerus)"
ID=ubuntu
ID_LIKE=debian
PRETTY_NAME="Ubuntu 16.04.6 LTS"
VERSION_ID="16.04"
但是我希望Ubuntu-18.04 LTS。 

如何将Ubuntu-16.04.6 LTS版本更改为Ubuntu-18.04 LTS？

我是Google App Engine的新成员，并试图将我的ASP.Net Core 3.1 Blazor网站部署到Google App Engine。我在Docker上使用了自定义版本，因为App Engine不支持.Net Core 3.1 ...

Answer 1

最后，我能够解决此问题。感谢breddy，它检查了我的Dockerfile。