I've recently hooked our CI servers up to build docker images upon git commit.
We have about 8 different containers that get built, each with their own language / frameworks. Some are node and have a package.json, others are python services that contain no semantic version information.
My question is not about how to create tags, its about creating the values for the tag.
How to ensure that each tag has a unique semantic version number for the specific images? Who should be the authority on tracking / incrementing a build version?