Rich Freeman wrote:
However, FWIW, linux namespaces cannot be used to have only a single file appear differently to different processes. Mount namespaces can only operate at the directory level.
So to work around that limitation we insist that everyone change how their systems are set up, and still have to reintroduce mtab under a different name ("utab", hidden away under /run) because /proc/self/mounts *doesn't* contain everything that's supposed to be in mtab after all?
If someone decides they want to use, say, different DNS servers in different namespaces, should we make the kernel store the server IP addresses, add a /proc file that dumps them out in the expected format, and demand that everyone replace their /etc/resolv.conf with a symlink to /proc/self/resolv.conf? Or maybe, if people want namespaces, they can implement them properly, in which case it becomes literally a self-solving problem.
