rebuild docker image from specific step

Question

I have the below Dockerfile.

FROM ubuntu:14.04
MAINTAINER Samuel Alexander 

RUN          


        

Answer 1

To complete Dmitry's answer, you can use uniq arg like date +%s to keep always same commanline

docker build --build-arg DUMMY=`date +%s` -t me/myapp:1.0.0

Dockerfile:

...
ARG DUMMY=unknown
RUN DUMMY=${DUMMY} git clone xxx
...