# Docker镜像优化
```shell
FROM microsoft/dotnet:2.1-aspnetcore-runtime AS base
WORKDIR /app
EXPOSE 80
FROM microsoft/dotnet:2.1-sdk AS build
WORKDIR /src
COPY ["API/API.csproj", "API/"]
RUN dotnet restore "API/API.csproj"
COPY . .
WORKDIR "/src/API"
RUN dotnet build "API.csproj" -c Release -o /app
FROM build AS publish
RUN dotnet publish "API.csproj" -c Release -o /app
FROM base AS final
WORKDIR /app
COPY --from=publish /app .
ENTRYPOINT ["dotnet", "API.dll"]
```
它分为四个阶段，分别是`base、build、publish和final`。
* base阶段：上面已经分析了这里不再详述。
* build阶段：
