使用 Dockerfile 文件但是不使用缓存生成镜像

　　前一段时候使用 Dockerfile 重新部署 NetCore3.1 项目的时候很顺利，由来由于一些原因，我把以前的镜像删除，如果我们大家继续使用 docker  build 命令去生成镜像的话就会报错，例如：
　　　　

[root@localhost PatrickLiu.NetCore]# docker build -t core31v1.112 -f Dockerfile .
Sending build context to Docker daemon  4.425MB
Step 1/17 : FROM mcr.microsoft.com/dotnet/core/aspnet:3.1-buster-slim AS base
 ---> e3559b2d50bb
Step 2/17 : WORKDIR /app
 ---> Using cache
 ---> 1c0ab1a505e2
Step 3/17 : EXPOSE 80
 ---> Using cache
 ---> 49a72547d567
Step 4/17 : EXPOSE 443
unable to find image "sha256:c5ed536f38a6742b7c084fa87e6ac885d9697960a20860f7fd0299da578cf2c8"

　　这样肯定是不行的，我们肯定希望使用没有缓存的方式重新加载文件生成镜像，怎么做呢？

　　问题

　　　　你想不用缓存重建Dockerfile。

　　解决方法

　　　　构建镜像时使用 --no-cache 参数。

　　讨论

　　　　为了强制docker构建镜像时不用缓存，执行带–no-cache参数的docker build命令。下面的示例是使用了–no-cache构建镜像。

　　效果如下：

[root@localhost PatrickLiu.NetCore]# docker build --no-cache -t core31v1.112 -f Dockerfile .
Sending build context to Docker daemon  4.425MB
Step 1/17 : FROM mcr.microsoft.com/dotnet/core/aspnet:3.1-buster-slim AS base
 ---> e3559b2d50bb
Step 2/17 : WORKDIR /app
 ---> Running in e8178063fe45
Removing intermediate container e8178063fe45
 ---> 0a1d582b30d4
Step 3/17 : EXPOSE 80
 ---> Running in e7716f388165
Removing intermediate container e7716f388165
 ---> fc54a6e3c0aa
Step 4/17 : EXPOSE 443
 ---> Running in 449680497b7f
Removing intermediate container 449680497b7f
 ---> acf106867ca0
Step 5/17 : FROM mcr.microsoft.com/dotnet/core/sdk:3.1-buster AS build
3.1-buster: Pulling from dotnet/core/sdk
e4c3d3e4f7b0: Pull complete 
101c41d0463b: Pull complete 
8275efcd805f: Pull complete 
751620502a7a: Pull complete 
8e306865fd07: Pull complete 
9d2f53e752c2: Downloading [===========================>                       ]  69.19MB/123.8MB
143a93e01eba: Download complete 

　　镜像文件重新生成，没有使用缓存，每天进步一点点，把问题记录下来，这就是成长了。继续努力。

　　镜像最后生成的胜利步骤。

[root@localhost PatrickLiu.NetCore]# docker build --no-cache -t core31v1.112 -f Dockerfile .
Sending build context to Docker daemon  4.425MB
Step 1/17 : FROM mcr.microsoft.com/dotnet/core/aspnet:3.1-buster-slim AS base
 ---> e3559b2d50bb
Step 2/17 : WORKDIR /app
 ---> Running in e8178063fe45
Removing intermediate container e8178063fe45
 ---> 0a1d582b30d4
Step 3/17 : EXPOSE 80
 ---> Running in e7716f388165
Removing intermediate container e7716f388165
 ---> fc54a6e3c0aa
Step 4/17 : EXPOSE 443
 ---> Running in 449680497b7f
Removing intermediate container 449680497b7f
 ---> acf106867ca0
Step 5/17 : FROM mcr.microsoft.com/dotnet/core/sdk:3.1-buster AS build
3.1-buster: Pulling from dotnet/core/sdk
e4c3d3e4f7b0: Pull complete 
101c41d0463b: Pull complete 
8275efcd805f: Pull complete 
751620502a7a: Pull complete 
8e306865fd07: Pull complete 
9d2f53e752c2: Pull complete 
143a93e01eba: Pull complete 
Digest: sha256:bfd6083e9cd36b37b2a4e9f1722cc958b6654fa96cb3d84ef78492ecf00dcd32
Status: Downloaded newer image for mcr.microsoft.com/dotnet/core/sdk:3.1-buster
 ---> 5fe503d51830
Step 6/17 : WORKDIR /src
 ---> Running in 4312c5d63f3f
Removing intermediate container 4312c5d63f3f
 ---> 31cfbe6739ec
Step 7/17 : COPY ["PatrickLiu.NetCore.MvcDemo/PatrickLiu.NetCore.MvcDemo.csproj", "PatrickLiu.NetCore.MvcDemo/"]
 ---> ba9ba79cc7d3
Step 8/17 : RUN dotnet restore "PatrickLiu.NetCore.MvcDemo/PatrickLiu.NetCore.MvcDemo.csproj"
 ---> Running in 8d2c9ee24614
  Determining projects to restore...
  Restored /src/PatrickLiu.NetCore.MvcDemo/PatrickLiu.NetCore.MvcDemo.csproj (in 4.64 sec).
Removing intermediate container 8d2c9ee24614
 ---> 872cce519821
Step 9/17 : COPY . .
 ---> 4fe062b14ab1
Step 10/17 : WORKDIR "/src/PatrickLiu.NetCore.MvcDemo"
 ---> Running in 431b1c2f4959
Removing intermediate container 431b1c2f4959
 ---> b9dc3acf883c
Step 11/17 : RUN dotnet build "PatrickLiu.NetCore.MvcDemo.csproj" -c Release -o /app/build
 ---> Running in 639b5e3d01df
Microsoft (R) Build Engine version 16.7.0+7fb82e5b2 for .NET
Copyright (C) Microsoft Corporation. All rights reserved.

  Determining projects to restore...
  All projects are up-to-date for restore.
  PatrickLiu.NetCore.MvcDemo -> /app/build/PatrickLiu.NetCore.MvcDemo.dll
  PatrickLiu.NetCore.MvcDemo -> /app/build/PatrickLiu.NetCore.MvcDemo.Views.dll

Build succeeded.
    0 Warning(s)
    0 Error(s)

Time Elapsed 00:00:19.21
Removing intermediate container 639b5e3d01df
 ---> aeb1df18b3f6
Step 12/17 : FROM build AS publish
 ---> aeb1df18b3f6
Step 13/17 : RUN dotnet publish "PatrickLiu.NetCore.MvcDemo.csproj" -c Release -o /app/publish
 ---> Running in ac663a5be455
Microsoft (R) Build Engine version 16.7.0+7fb82e5b2 for .NET
Copyright (C) Microsoft Corporation. All rights reserved.

  Determining projects to restore...
  All projects are up-to-date for restore.
  PatrickLiu.NetCore.MvcDemo -> /src/PatrickLiu.NetCore.MvcDemo/bin/Release/netcoreapp3.1/PatrickLiu.NetCore.MvcDemo.dll
  PatrickLiu.NetCore.MvcDemo -> /src/PatrickLiu.NetCore.MvcDemo/bin/Release/netcoreapp3.1/PatrickLiu.NetCore.MvcDemo.Views.dll
  PatrickLiu.NetCore.MvcDemo -> /app/publish/
Removing intermediate container ac663a5be455
 ---> 6ffbf30a49af
Step 14/17 : FROM base AS final
 ---> acf106867ca0
Step 15/17 : WORKDIR /app
 ---> Running in 3dca58d70bef
Removing intermediate container 3dca58d70bef
 ---> 37d1ad5bb22b
Step 16/17 : COPY --from=publish /app/publish .
 ---> 09de2a366451
Step 17/17 : ENTRYPOINT ["dotnet", "PatrickLiu.NetCore.MvcDemo.dll"]
 ---> Running in 2c41d28e90dc
Removing intermediate container 2c41d28e90dc
 ---> 8bf4c94fbc04
Successfully built 8bf4c94fbc04
Successfully tagged core31v1.112:latest

　　　　结束了。