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：
1 [root@localhost PatrickLiu.NetCore]# docker build -t core31v1.112 -f Dockerfile . 2 Sending build context to Docker daemon 4.425MB 3 Step 1/17 : FROM mcr.microsoft.com/dotnet/core/aspnet:3.1-buster-slim AS base 4 ---> e3559b2d50bb 5 Step 2/17 : WORKDIR /app 6 ---> Using cache 7 ---> 1c0ab1a505e2 8 Step 3/17 : EXPOSE 80 9 ---> Using cache 10 ---> 49a72547d567 11 Step 4/17 : EXPOSE 443 12 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：
1 [root@localhost PatrickLiu.NetCore]# docker build --no-cache -t core31v1.112 -f Dockerfile . 2 Sending build context to Docker daemon 4.425MB 3 Step 1/17 : FROM mcr.microsoft.com/dotnet/core/aspnet:3.1-buster-slim AS base 4 ---> e3559b2d50bb 5 Step 2/17 : WORKDIR /app 6 ---> Running in e8178063fe45 7 Removing intermediate container e8178063fe45 8 ---> 0a1d582b30d4 9 Step 3/17 : EXPOSE 80 10 ---> Running in e7716f388165 11 Removing intermediate container e7716f388165 12 ---> fc54a6e3c0aa 13 Step 4/17 : EXPOSE 443 14 ---> Running in 449680497b7f 15 Removing intermediate container 449680497b7f 16 ---> acf106867ca0 17 Step 5/17 : FROM mcr.microsoft.com/dotnet/core/sdk:3.1-buster AS build 18 3.1-buster: Pulling from dotnet/core/sdk 19 e4c3d3e4f7b0: Pull complete 20 101c41d0463b: Pull complete 21 8275efcd805f: Pull complete 22 751620502a7a: Pull complete 23 8e306865fd07: Pull complete 24 9d2f53e752c2: Downloading [===========================> ] 69.19MB/123.8MB 25 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。
1 [root@localhost PatrickLiu.NetCore]# docker build --no-cache -t core31v1.112 -f Dockerfile . 2 Sending build context to Docker daemon 4.425MB 3 Step 1/17 : FROM mcr.microsoft.com/dotnet/core/aspnet:3.1-buster-slim AS base 4 ---> e3559b2d50bb 5 Step 2/17 : WORKDIR /app 6 ---> Running in e8178063fe45 7 Removing intermediate container e8178063fe45 8 ---> 0a1d582b30d4 9 Step 3/17 : EXPOSE 80 10 ---> Running in e7716f388165 11 Removing intermediate container e7716f388165 12 ---> fc54a6e3c0aa 13 Step 4/17 : EXPOSE 443 14 ---> Running in 449680497b7f 15 Removing intermediate container 449680497b7f 16 ---> acf106867ca0 17 Step 5/17 : FROM mcr.microsoft.com/dotnet/core/sdk:3.1-buster AS build 18 3.1-buster: Pulling from dotnet/core/sdk 19 e4c3d3e4f7b0: Pull complete 20 101c41d0463b: Pull complete 21 8275efcd805f: Pull complete 22 751620502a7a: Pull complete 23 8e306865fd07: Pull complete 24 9d2f53e752c2: Pull complete 25 143a93e01eba: Pull complete 26 Digest: sha256:bfd6083e9cd36b37b2a4e9f1722cc958b6654fa96cb3d84ef78492ecf00dcd32 27 Status: Downloaded newer image for mcr.microsoft.com/dotnet/core/sdk:3.1-buster 28 ---> 5fe503d51830 29 Step 6/17 : WORKDIR /src 30 ---> Running in 4312c5d63f3f 31 Removing intermediate container 4312c5d63f3f 32 ---> 31cfbe6739ec 33 Step 7/17 : COPY ["PatrickLiu.NetCore.MvcDemo/PatrickLiu.NetCore.MvcDemo.csproj", "PatrickLiu.NetCore.MvcDemo/"] 34 ---> ba9ba79cc7d3 35 Step 8/17 : RUN dotnet restore "PatrickLiu.NetCore.MvcDemo/PatrickLiu.NetCore.MvcDemo.csproj" 36 ---> Running in 8d2c9ee24614 37 Determining projects to restore... 38 Restored /src/PatrickLiu.NetCore.MvcDemo/PatrickLiu.NetCore.MvcDemo.csproj (in 4.64 sec). 39 Removing intermediate container 8d2c9ee24614 40 ---> 872cce519821 41 Step 9/17 : COPY . . 42 ---> 4fe062b14ab1 43 Step 10/17 : WORKDIR "/src/PatrickLiu.NetCore.MvcDemo" 44 ---> Running in 431b1c2f4959 45 Removing intermediate container 431b1c2f4959 46 ---> b9dc3acf883c 47 Step 11/17 : RUN dotnet build "PatrickLiu.NetCore.MvcDemo.csproj" -c Release -o /app/build 48 ---> Running in 639b5e3d01df 49 Microsoft (R) Build Engine version 16.7.0+7fb82e5b2 for .NET 50 Copyright (C) Microsoft Corporation. All rights reserved. 51 52 Determining projects to restore... 53 All projects are up-to-date for restore. 54 PatrickLiu.NetCore.MvcDemo -> /app/build/PatrickLiu.NetCore.MvcDemo.dll 55 PatrickLiu.NetCore.MvcDemo -> /app/build/PatrickLiu.NetCore.MvcDemo.Views.dll 56 57 Build succeeded. 58 0 Warning(s) 59 0 Error(s) 60 61 Time Elapsed 00:00:19.21 62 Removing intermediate container 639b5e3d01df 63 ---> aeb1df18b3f6 64 Step 12/17 : FROM build AS publish 65 ---> aeb1df18b3f6 66 Step 13/17 : RUN dotnet publish "PatrickLiu.NetCore.MvcDemo.csproj" -c Release -o /app/publish 67 ---> Running in ac663a5be455 68 Microsoft (R) Build Engine version 16.7.0+7fb82e5b2 for .NET 69 Copyright (C) Microsoft Corporation. All rights reserved. 70 71 Determining projects to restore... 72 All projects are up-to-date for restore. 73 PatrickLiu.NetCore.MvcDemo -> /src/PatrickLiu.NetCore.MvcDemo/bin/Release/netcoreapp3.1/PatrickLiu.NetCore.MvcDemo.dll 74 PatrickLiu.NetCore.MvcDemo -> /src/PatrickLiu.NetCore.MvcDemo/bin/Release/netcoreapp3.1/PatrickLiu.NetCore.MvcDemo.Views.dll 75 PatrickLiu.NetCore.MvcDemo -> /app/publish/ 76 Removing intermediate container ac663a5be455 77 ---> 6ffbf30a49af 78 Step 14/17 : FROM base AS final 79 ---> acf106867ca0 80 Step 15/17 : WORKDIR /app 81 ---> Running in 3dca58d70bef 82 Removing intermediate container 3dca58d70bef 83 ---> 37d1ad5bb22b 84 Step 16/17 : COPY --from=publish /app/publish . 85 ---> 09de2a366451 86 Step 17/17 : ENTRYPOINT ["dotnet", "PatrickLiu.NetCore.MvcDemo.dll"] 87 ---> Running in 2c41d28e90dc 88 Removing intermediate container 2c41d28e90dc 89 ---> 8bf4c94fbc04 90 Successfully built 8bf4c94fbc04 91 Successfully tagged core31v1.112:latest
结束了。