反向提取dockerfile

alpine/dfimage: 这个工具是由Whaler 工具构建而来，它可以比较全面的展示一个镜像的构建过程

它可以实现

从一个docker镜像生成Dockerfile内容
搜索添加的文件名以查找潜在的秘密文件
提取Docker ADD/COPY指令添加的文件
展示暴露的端口、环境变量信息等等

使用方法：

$ docker run -v /var/run/docker.sock:/var/run/docker.sock --rm alpine/dfimage jiaxzeng/fileserver:v1.2.0-alpine3.16
Analyzing jiaxzeng/fileserver:v1.2.0-alpine3.16
Docker Version: 
GraphDriver: overlay2
Environment Variables
|PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin

Image user
|User is root

Potential secrets:
|Found match etc/apk/keys/alpine-devel@lists.alpinelinux.org-4a6a0840.rsa.pub Possible public key \.pub$ 4f58d646009c9dfd36dae69fa685fbcfcec7e9b32e8f67abba71b4141b279271/layer.tar
|Found match etc/apk/keys/alpine-devel@lists.alpinelinux.org-5243ef4b.rsa.pub Possible public key \.pub$ 4f58d646009c9dfd36dae69fa685fbcfcec7e9b32e8f67abba71b4141b279271/layer.tar
|Found match etc/apk/keys/alpine-devel@lists.alpinelinux.org-5261cecb.rsa.pub Possible public key \.pub$ 4f58d646009c9dfd36dae69fa685fbcfcec7e9b32e8f67abba71b4141b279271/layer.tar
|Found match etc/apk/keys/alpine-devel@lists.alpinelinux.org-6165ee59.rsa.pub Possible public key \.pub$ 4f58d646009c9dfd36dae69fa685fbcfcec7e9b32e8f67abba71b4141b279271/layer.tar
|Found match etc/apk/keys/alpine-devel@lists.alpinelinux.org-61666e3f.rsa.pub Possible public key \.pub$ 4f58d646009c9dfd36dae69fa685fbcfcec7e9b32e8f67abba71b4141b279271/layer.tar
|Found match etc/udhcpd.conf DHCP server configs dhcpd[^ ]*.conf 4f58d646009c9dfd36dae69fa685fbcfcec7e9b32e8f67abba71b4141b279271/layer.tar
Dockerfile:
CMD ["/bin/sh"]
LABEL author=jiaxzeng
LABEL project=https://caddyserver.com/docs
COPY /tmp/caddy /usr/local/bin/caddy # buildkit
        usr/
        usr/local/
        usr/local/bin/
        usr/local/bin/caddy

COPY Caddyfile /app/caddy/Caddyfile # buildkit
        app/
        app/caddy/
        app/caddy/Caddyfile

RUN RUN sed -i 's@dl-cdn.alpinelinux.org@mirrors.aliyun.com@g' /etc/apk/repositories  \
        && apk --no-cache add curl bash # buildkit
WORKDIR /app/caddy
ENTRYPOINT ["/usr/local/bin/caddy" "run"]