What are user namespaces? Sticking with the apartment complex analogy, the numbering of users and groups have historically been the same in every container and in the underlying host, just like public channel 10 is generally the same in every unit in an apartment building.
But, imagine that people in different apartments are getting their television signal from different cable and satellite companies. Channel 10 is now different for for each person. It might be sports for one person, and news for another.
Historically, in the Linux kernel, there was a single data structure which held users and groups. Starting in kernel version 3.8
View original post 679 more words