dockerfile-from-image

> Extract Dockerfile from image.
> 从镜像中提取 Dockerfile

使用方法

#### npm 模块

``sh
$ npm i -g dockerfile-from-image # 安装命令行工具
$ dfimage nginx:alpine # 命令行显示
$ dfimage nginx:alpine > Dockerfile # 输出到文件
`

#### docker 镜像

`sh
$ docker run --rm -v /var/run/docker.sock:/var/run/docker.sock toomee/dockerfile-from-image nginx:alpine
`

配置别名

`sh
$ alias dfimage="docker run --rm -v /var/run/docker.sock:/var/run/docker.sock toomee/dockerfile-from-image"
$ dfimage nginx:alpine
`

示例

`dockerfile
$ dfimage node:8-alpine

FROM node:8-alpine
ADD file:25c10b1d1b41d46a1827ad0b0d2389c24df6d31430005ff4e9a2d84ea23ebd42 in /
CMD ["/bin/sh"]
ENV NODE_VERSION=8.12.0
RUN addgroup -g 1000 node \
&& adduser -u 1000 -G node -s /bin/sh -D node \
&& apk add --no-cache \
libstdc++ \
&& apk add --no-cache --virtual .build-deps \
binutils-gold \
curl \
g++ \
gcc \
gnupg \
libgcc \
linux-headers \
make \
python \
&& for key in \
94AE36675C464D64BAFA68DD7434390BDBE9B9C5 \
FD3A5288F042B6850C66B31F09FE44734EB7990E \
71DCFD284A79C3B38668286BC97EC7A07EDE3FC1 \
DD8F2338BAE7501E3DD5AC78C273792F7D83545D \
C4F0DFFF4E8C1A8236409D08E73BC641CC11F4C8 \
B9AE9905FFD7803F25714661B63B535A4C206CA9 \
56730D5401028683275BD23C23EFEFE93C4CFFFE \
77984A986EBC2AA786BC0F66B01FBB92821C587A \
8FCCA13FEF1D0C2E91008E09770F7A9A5AE15600 \
; do \
gpg --keyserver hkp://p80.pool.sks-keyservers.net:80 --recv-keys "$key" || \
gpg --keyserver hkp://ipv4.pool.sks-keyservers.net --recv-keys "$key" || \
gpg --keyserver hkp://pgp.mit.edu:80 --recv-keys "$key" ; \
done \
&& curl -fsSLO --compressed "https://nodejs.org/dist/v$NODE_VERSION/node-v$NODE_VERSION.tar.xz" \
&& curl -fsSLO --compressed "https://nodejs.org/dist/v$NODE_VERSION/SHASUMS256.txt.asc" \
&& gpg --batch --decrypt --output SHASUMS256.txt SHASUMS256.txt.asc \
&& grep " node-v$NODE_VERSION.tar.xz\$" SHASUMS256.txt | sha256sum -c - \
&& tar -xf "node-v$NODE_VERSION.tar.xz" \
&& cd "node-v$NODE_VERSION" \
&& ./configure \
&& make -j$(getconf _NPROCESSORS_ONLN) \
&& make install \
&& apk del .build-deps \
&& cd .. \
&& rm -Rf "node-v$NODE_VERSION" \
&& rm "node-v$NODE_VERSION.tar.xz" SHASUMS256.txt.asc SHASUMS256.txt
ENV YARN_VERSION=1.9.4
RUN apk add --no-cache --virtual .build-deps-yarn curl gnupg tar \
&& for key in \
6A010C5166006599AA17F08146C2130DFD2497F5 \
; do \
gpg --keyserver hkp://p80.pool.sks-keyservers.net:80 --recv-keys "$key" || \
gpg --keyserver hkp://ipv4.pool.sks-keyservers.net --recv-keys "$key" || \
gpg --keyserver hkp://pgp.mit.edu:80 --recv-keys "$key" ; \
done \
&& curl -fsSLO --compressed "https://yarnpkg.com/downloads/$YARN_VERSION/yarn-v$YARN_VERSION.tar.gz" \
&& curl -fsSLO --compressed "https://yarnpkg.com/downloads/$YARN_VERSION/yarn-v$YARN_VERSION.tar.gz.asc" \
&& gpg --batch --verify yarn-v$YARN_VERSION.tar.gz.asc yarn-v$YARN_VERSION.tar.gz \
&& mkdir -p /opt \
&& tar -xzf yarn-v$YARN_VERSION.tar.gz -C /opt/ \
&& ln -s /opt/yarn-v$YARN_VERSION/bin/yarn /usr/local/bin/yarn \
&& ln -s /opt/yarn-v$YARN_VERSION/bin/yarnpkg /usr/local/bin/yarnpkg \
&& rm yarn-v$YARN_VERSION.tar.gz.asc yarn-v$YARN_VERSION.tar.gz \
&& apk del .build-deps-yarn
CMD ["node"]
`

注意

1. 是从 docker history --no-trunc 结果中整理出的配置
1. 所以其中 FROM 并非根镜像，而是当前镜像名。
1. 开头两个 ADD CMD` 是根镜像的层，通常可以忽略。