How to increment docker tag automatically?

Question

I am planning to increment docker tag automatically using shell script. Right now i am using Date function to insert %m%d%y%H%M for docker tag. Every time, current month year and date with Hours and mins are inserting like 03262016091.

But when I see it in Docker hub, it's not looking good and planning to keep the version names as 1.0.0 or with git commit number.

I am using Travis CI for my continuous Integration but not to build docker images. I have shell script to do that using Docker file.

My Requirement is:

I have to increment below version number everytime when I execute my build.

Version=1.0.0

Could you please help me how to do this?

Answer 1

You could use the git revision which is unique as well. Most simple solution from the command line is a nested git-rev command:

docker tag <image> <image>:$(git rev-parse --short HEAD)"

gives you e.g.

<image> = myImage >> myImage:67df348

Answer 2

If your repository were named your/project and was tagged with 1.0, then following should rebuild it with tag 1.01:

docker build -t your/project:$(docker images | awk '($1 == "your/project") {print $2 += .01; exit}') .