Suggestion: adding function which multi-files can be aware of soft/hard limit

[jansu-dev]

Feature Request

Is your feature request related to a problem? Please describe:

Describe the feature you'd like:

Oringinal Problem: https://asktug.com/t/topic/1010766

if user manually config soft/hard limit in other configure files, like /etc/security/limits.d/tidb.conf , instead of /etc/security/limits.d/ which doc has already told, though.
related config can not be aware, however, other databases can do it, like Oracle ...

Why the featue is needed:

we wanna TiUP can do it like Oracle.

Describe alternatives you've considered:

Teachability, Documentation, Adoption, Migration Strategy:

[chenyz1984]

The capacity of reading the soft/hard limit from the file in directory /etc/security/limits.d/ is the Linux OS standard, as descrption in the global soft/hard limit file /etc/security/limits.conf is:

cat /etc/security/limits.conf 

# /etc/security/limits.conf
#
#This file sets the resource limits for the users logged in via PAM.
#It does not affect resource limits of the system services.
#
#Also note that configuration files in /etc/security/limits.d directory,
#which are read in alphabetical order, override the settings in this
#file in case the domain is the same or more specific.
#That means, for example, that setting a limit for wildcard domain here
#can be overridden with a wildcard setting in a config file in the
#subdirectory, but a user specific setting here can be overridden only
#with a user specific setting in the subdirectory.
#
#Each line describes a limit for a user in the form:
#
#<domain>        <type>  <item>  <value>
#