Comment 4 for bug 1760471

Latest Docker changes on NOFILE ulimit:

* 2014: https://github.com/moby/moby/commit/7abe70c0b1018729006fd5d614ada2dc67edb9b2
* 2016: https://github.com/moby/moby/commit/428d7337e808ec5f4dba1b0aceda002f295cc320

It seems like the 1048576 value (2^20) comes from the maximum allowed value in RHEL 5:
http://stackoverflow.com/a/1213069/1811501

"RHEL 5 has a maximum value of 1048576 (220) for this limit (NR_OPEN in /usr/include/linux/fs.h), and will not accept any larger value including infinity, even for root. So on RHEL 5 you can use this value in /etc/security/limits.conf and that is as close as you are going to get to infinity."