image - dockerfile 中的 AS 基础和 AS 构建有什么区别？

Question

我想知道FROM mcr.microsoft.com/dotnet/core/aspnet:2.1-stretch-slim AS base的区别和 FROM mcr.microsoft.com/dotnet/core/sdk:2.1-stretch AS build .你能解释一下AS base之间的区别吗？和 AS build ?
这是默认值 dockerfile由 Visual Studio 生成:

FROM mcr.microsoft.com/dotnet/core/aspnet:2.1-stretch-slim AS base
WORKDIR /app
EXPOSE 80
EXPOSE 443

FROM mcr.microsoft.com/dotnet/core/sdk:2.1-stretch AS build
WORKDIR /src
COPY ["WebApplication1/WebApplication1.csproj", "WebApplication1/"]
RUN dotnet restore "WebApplication1/WebApplication1.csproj"
COPY . .
WORKDIR "/src/WebApplication1"
RUN dotnet build "WebApplication1.csproj" -c Release -o /app

FROM build AS publish
RUN dotnet publish "WebApplication1.csproj" -c Release -o /app

FROM base AS final
WORKDIR /app
COPY --from=publish /app .
ENTRYPOINT ["dotnet", "WebApplication1.dll"]

Answer 1

没有功能差异，它只是构建阶段的名称。在 dockerfile 的这个阶段构建的图像(阶段以 FROM 关键字开始，在下一个 FROM 之前结束)稍后将可以使用该名称访问。

Optionally a name can be given to a new build stage by adding AS name to the FROM instruction. The name can be used in subsequent FROM and COPY --from=<name|index> instructions to refer to the image built in this stage.

https://docs.docker.com/engine/reference/builder/#from

例如，姓名 foo和 bar

FROM image AS foo
...
...

FROM foo AS bar
...
...

FROM foo
COPY --from=bar

它是在 17.05 中为多阶段构建添加的，更多内容是:https://docs.docker.com/develop/develop-images/multistage-build/