I'm trying to contribute with Docker's install script by providing auto distribution detection support for elementary OS, so, elementary OS users would be automatically detected when using Docker's official install script.
The script will add an apt repository with the following command:
echo "deb https://apt.dockerproject.org/repo ${lsb_dist}-${dist_version} ${repo}" > /etc/apt/sources.list.d/docker.list
Where lsb_dist=elementary, dist_version=freya and repo=main in Freya.
After that it'll do apt-get update and install the "docker-engine" package.
Though, Docker apt repository doesn't have entries for elementary OS. I've tested using "ubuntu-trusty" repository and it works just fine in Freya.
So, I want to use Ubuntu repositories to setup Docker for elementary, but I would like to avoid hard coding elementary OS correspondent base Ubuntu versions, if that's possible.
Question:
Is there a file or command which will tell me what's elementary OS' base Ubuntu version, and works in all elementary OS versions?