How to rebuild dockerfile quick by using cache?

Question

I want to optimize my Dockerfile. And I wish to keep cache file in disk. But, I found when I run docker build . It always try to get every file from network.

<

Answer 1

Just use an intermediate/base image:

Base Dockerfile, build it with docker build -t custom-base or something:

FROM centos:6.4
RUN yum update -y
RUN yum install -y openssh-server vim
RUN sed -i -e 's:keepcache=0:keepcache=1:' /etc/yum.conf

Application Dockerfile:

FROM custom-base
VOLUME ["/var/cache/yum/x86_64/6"] 
EXPOSE 22