我们有时候想知道官方镜像的dockerfile是怎么写的，需要根据docker image 反推docker file
后来发现docker history命令可以帮助我们实现这个需求，具体如下：

命令：
docker history --format {{.CreatedBy}} --no-trunc=true java:8|sed "s?/bin/sh\ -c\ \#(nop)\ ??g"|sed "s?/bin/sh\ -c?RUN?g" | tac

示例：

> docker history --format {{.CreatedBy}} --no-trunc=true java:8|sed "s?/bin/sh\ -c\ \#(nop)\ ??g"|sed "s?/bin/sh\ -c?RUN?g" | tac

ADD file:89ecb642d662ee7edbb868340551106d51336c7e589fdaca4111725ec64da957 in / 
 CMD ["/bin/bash"]
RUN apt-get update && apt-get install -y --no-install-recommends   ca-certificates   curl   wget  && rm -rf /var/lib/apt/lists/*
RUN apt-get update && apt-get install -y --no-install-recommends   bzr   git   mercurial   openssh-client   subversion     procps  && rm -rf /var/lib/apt/lists/*
RUN apt-get update && apt-get install -y --no-install-recommends   bzip2   unzip   xz-utils  && rm -rf /var/lib/apt/lists/*
RUN echo 'deb http://deb.debian.org/debian jessie-backports main' > /etc/apt/sources.list.d/jessie-backports.list
 ENV LANG=C.UTF-8
RUN {   echo '#!/bin/sh';   echo 'set -e';   echo;   echo 'dirname "$(dirname "$(readlink -f "$(which javac || which java)")")"';  } > /usr/local/bin/docker-java-home  && chmod +x /usr/local/bin/docker-java-home
 ENV JAVA_HOME=/usr/lib/jvm/java-8-openjdk-amd64
 ENV JAVA_VERSION=8u111
 ENV JAVA_DEBIAN_VERSION=8u111-b14-2~bpo8+1
 ENV CA_CERTIFICATES_JAVA_VERSION=20140324
RUN set -x  && apt-get update  && apt-get install -y   openjdk-8-jdk="$JAVA_DEBIAN_VERSION"   ca-certificates-java="$CA_CERTIFICATES_JAVA_VERSION"  && rm -rf /var/lib/apt/lists/*  && [ "$JAVA_HOME" = "$(docker-java-home)" ]
RUN /var/lib/dpkg/info/ca-certificates-java.postinst configure