How to build docker image from github repository

Question

In official docs we can see:

# docker build github.com/creack/docker-firefox

It just works fine to me. docker-firefox is a reposit

Answer 1

docker build url#ref:dir

Git URLs accept context configuration in their fragment section, separated by a colon :. The first part represents the reference that Git will check out, this can be either a branch, a tag, or a commit SHA. The second part represents a subdirectory inside the repository that will be used as a build context.

For example, run this command to use a directory called docker in the branch container:

docker build https://github.com/docker/rootfs.git#container:docker

https://docs.docker.com/engine/reference/commandline/build/