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。
$ docker build --no-cache . Sending build context to Docker daemon 2.56 kB Sending build context to Docker daemon Step 0 : FROM node ---> 91cbcf796c2c Step 1 : MAINTAINER [email protected] ---> Running in ca243b77f6a1 ---> 602f1294d7f1 Removing intermediate container ca243b77f6a1 Step 2 : RUN git clone -q https://github.com/docker-in-practice/todo.git ---> Running in f2c0ac021247 ---> 04ee24faaf18 Removing intermediate container f2c0ac021247 Step 3 : WORKDIR todo ---> Running in c2d9cd32c182 ---> 4e0029de9074 Removing intermediate container c2d9cd32c182 Step 4 : RUN npm install > /dev/null ---> Running in 79122dbf9e52 npm WARN package.json [email protected] No repository field. ---> 9b6531f2036a Removing intermediate container 79122dbf9e52 Step 5 : EXPOSE 8000 ---> Running in d1d58e1c4b15 ---> f7c1b9151108 Removing intermediate container d1d58e1c4b15 Step 6 : CMD npm start ---> Running in 697713ebb185 ---> 74f9ad384859 Removing intermediate container 697713ebb185 Successfully built 74f9ad384859
以上的构建镜像步骤没有使用到缓存，每一层的镜像ID都与之间的不同。