未应用 ASPNETCORE_URLS（在 docker 容器中部署）

Question

我正在尝试让我的 asp.net 核心应用程序使用 ASPNETCORE_URLS 来设置启动 URL。它没有按预期工作。

我已经尝试了我在网上找到的所有东西，但我一直被卡住。该应用程序在没有环境变量的情况下工作，并在 docker 容器中正常运行。但是在启用环境变量时不起作用。

期望结果：0.0.0.0:5000 结果：本地主机：5000

启动：

        public Startup(IConfiguration configuration, IWebHostEnvironment env)
    {
        Configuration = new ConfigurationBuilder()
             .SetBasePath(env.ContentRootPath)
          .AddJsonFile("appsettings.json")
          .AddJsonFile($"appsettings.{env.EnvironmentName}.json")
          .AddEnvironmentVariables()
          .Build();
    }

dockerfile 中的环境变量：

ENV ASPNETCORE_URLS=http://+:5000

码头工人文件：

#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/core/aspnet:3.1-buster-slim AS base
WORKDIR /app
EXPOSE 5000
ENV ASPNETCORE_URLS=http://+:5000

FROM mcr.microsoft.com/dotnet/core/sdk:3.1-buster AS build
WORKDIR /src
COPY ["Platform/Platform.API/Platform.API.csproj", "Platform.API/"]
COPY ["Platform/Platform.Domain/Platform.Domain.csproj", "Platform.Domain/"]
COPY ["Platform/Platform.DataAccess/Platform.DataAccess.csproj", "Platform.DataAccess/"]
RUN dotnet restore "Platform.API/Platform.API.csproj"
COPY ./Platform .
WORKDIR "/src/Platform.API"
RUN dotnet build "Platform.API.csproj" -c Release -o /app/build

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

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

应用程序检测到环境变量，只是出于某种原因不会使用它。

提前致谢！

Answer 1

这是将ENV关键字DOCKERFILE 移动到应用程序图像以产生效果的常见误解

FROM base AS final
WORKDIR /app
ENV ASPNETCORE_URLS=http://+:5000
COPY --from=publish /app/publish .
ENTRYPOINT ["dotnet", "Platform.API.dll"]

ENV根据dockerfile 参考，关键字适用于当前构建阶段

ENV 指令将环境变量设置为 value 。此值将在构建阶段的所有后续指令的环境中，并且也可以在许多中内联替换。

FROM 然而开始一个新的构建阶段

FROM 指令初始化一个新的构建阶段并为后续指令设置基础镜像。因此，有效的 Dockerfile 必须以 FROM 指令开头。

你可以通过构建这个来尝试这个 DOCKERFILE

from alpine
ENV asdf test
RUN echo $asdf

from alpine
RUN echo $asdf

返回

$ docker build -t envtest .
Sending build context to Docker daemon  6.656kB
Step 1/5 : from alpine
 ---> 5cb3aa00f899
Step 2/5 : ENV asdf test
 ---> Running in 91ae4904857e
Removing intermediate container 91ae4904857e
 ---> 63ef857d07a6
Step 3/5 : RUN echo $asdf       <------ works in same build stage
 ---> Running in b9037c76cc93
test
Removing intermediate container b9037c76cc93
 ---> 17edf57d8055
Step 4/5 : from alpine
 ---> 5cb3aa00f899
Step 5/5 : RUN echo $asdf       <------- does not in next build stage
 ---> Running in 62b42e7c28d8

Removing intermediate container 62b42e7c28d8
 ---> 7e6a8a58442f
Successfully built 7e6a8a58442f
Successfully tagged envtest:latest