Consider the blix command (I made it up), which blixes things.
It requires configuration information.
The straightforward solution is to have a configuration file,
/etc/blix.conf. It’s installed as part of the blix package,
and contains default values, such as:
Frequency: 30m # Every 30 minutes
Priority: medium
Level: 3 # 1 is lowest level, 5 is highest level
Users: root # Only root is permitted to blix
To allow user sanchez to blix, change the last line to:
Users: root,sanchez # Sanchez, too!
What happens when a new revision of the blix package comes out?
A new parameter has been added to /etc/blix.conf. However,
you’ve edited /etc/blix.conf:
| Old | New |
|---|---|
Frequency: 30m
Priority: medium
Level: 3
Users: root,sanchez
|
Frequency: 30m
Priority: medium
Level: 3
Users: root
Compression: xz
|
Conflict! When you update, you’ll have to merge that file manually. Ack!
You could have separate system & user config files:
/etc/blix.system.conf
/etc/blix.user.conf
/etc/blix.system.conf would be reserved for the system defaults,
and /etc/blix.user.conf would be available for user editing.
That sounds great, but …
What if another package wants to add some blixing information?
Say that the vim package wants to add a line to the blix
configuration file to specify how often ~/.vimrc should be blixed?
Whichever file it modifies, we’ll have the same old problem at the next update.
What are we supposed to do—have an unlimited number of configuration files!?
/etc/blix.conf
/etc/blix.system.conf & /etc/blix.user.conf
/etc/blix.d/*
Instead of a single configuration file /etc/blix.conf, or just a few
config files, have a directory /etc/blix.d.
The blix program will treat all files in /etc/blix.d as configuration
file.
If the order matters, we can add prefixes to the filenames to force processing order:
/etc/blix.d/40-vim (part of the vim package)
/etc/blix.d/50-blix (defaults provided as part of the blix package)
/etc/blix.d/90-user (created by the user)
The filenames will be unique, as long as two packages don’t use the same name.
$ ls -ld /etc/*.d drwxr-xr-x. 2 root root 4096 Apr 7 2024 /etc/ant.d drwxr-xr-x. 2 root root 4096 Apr 6 2024 /etc/auto.master.d drwxr-xr-x. 2 root root 4096 Oct 31 16:25 /etc/bash_completion.d drwxr-xr-x. 2 root root 4096 Sep 23 20:25 /etc/binfmt.d drwxr-xr-x. 2 root root 4096 Oct 14 2023 /etc/chkconfig.d drwxr-xr-x. 2 root root 4096 Apr 6 2024 /etc/cron.d drwxr-xr-x. 2 root root 4096 Jun 27 15:38 /etc/depmod.d drwxr-xr-x. 2 root dnsmasq 4096 May 22 2024 /etc/dnsmasq.d drwxr-xr-x. 2 root root 4096 Apr 6 2024 /etc/dracut.conf.d drwxr-xr-x. 2 root root 4096 Mar 31 2023 /etc/exports.d drwxr-xr-x. 2 root root 4096 Oct 31 16:22 /etc/gdbinit.d drwx------. 2 root root 4096 Jun 27 15:34 /etc/grub.d lrwxrwxrwx 1 root root 11 Oct 14 2023 /etc/init.d -> rc.d/init.d drwx------. 3 root root 4096 Jul 9 02:57 /etc/ipsec.d drwxr-xr-x. 2 root root 4096 Sep 7 2021 /etc/issue.d drwxr-xr-x. 2 root root 4096 Aug 13 13:55 /etc/krb5.conf.d drwxr-xr-x. 2 root root 4096 Oct 31 16:42 /etc/ld.so.conf.d drwxr-xr-x. 2 root root 4096 Apr 6 2024 /etc/libibverbs.d drwxr-xr-x. 2 root root 4096 Oct 12 2019 /etc/libpaper.d drwxr-xr-x. 2 root root 4096 Oct 31 16:22 /etc/logrotate.d drwxr-xr-x. 2 root root 4096 Sep 7 2021 /etc/lsb-release.d drwxr-xr-x 3 root root 4096 Apr 18 2022 /etc/mdevctl.d drwxr-xr-x. 2 root root 4096 Oct 31 16:22 /etc/modprobe.d drwxr-xr-x. 2 root root 4096 Sep 23 20:25 /etc/modules-load.d drwxr-xr-x. 2 root root 4096 Jul 2 14:16 /etc/motd.d drwxr-xr-x. 2 root root 4096 Sep 7 2021 /etc/my.cnf.d drwxr-xr-x. 2 root root 4096 Apr 1 2023 /etc/oddjobd.conf.d drwxr-xr-x. 2 root root 4096 Oct 31 16:26 /etc/pam.d drwxr-xr-x. 2 root root 4096 Jan 4 2022 /etc/php.d drwxr-xr-x. 2 root root 4096 Sep 7 2021 /etc/php-fpm.d drwxr-xr-x. 2 root root 4096 Apr 28 2023 /etc/popt.d drwxr-xr-x. 2 root root 4096 Oct 31 16:22 /etc/prelink.conf.d drwxr-xr-x. 2 root root 4096 Sep 19 16:59 /etc/profile.d lrwxrwxrwx 1 root root 10 Oct 14 2023 /etc/rc0.d -> rc.d/rc0.d lrwxrwxrwx 1 root root 10 Oct 14 2023 /etc/rc1.d -> rc.d/rc1.d lrwxrwxrwx 1 root root 10 Oct 14 2023 /etc/rc2.d -> rc.d/rc2.d lrwxrwxrwx 1 root root 10 Oct 14 2023 /etc/rc3.d -> rc.d/rc3.d lrwxrwxrwx 1 root root 10 Oct 14 2023 /etc/rc4.d -> rc.d/rc4.d lrwxrwxrwx 1 root root 10 Oct 14 2023 /etc/rc5.d -> rc.d/rc5.d lrwxrwxrwx 1 root root 10 Oct 14 2023 /etc/rc6.d -> rc.d/rc6.d drwxr-xr-x. 10 root root 4096 Sep 23 20:25 /etc/rc.d drwxr-xr-x. 2 root root 4096 Apr 18 2022 /etc/reader.conf.d drwxr-xr-x. 2 root root 4096 Oct 8 2021 /etc/request-key.d drwxr-xr-x. 2 root root 4096 Oct 14 2023 /etc/rsyslog.d drwxr-xr-x. 2 root root 4096 Aug 14 04:25 /etc/rwtab.d drwxr-xr-x. 3 root root 4096 Sep 7 2021 /etc/sane.d drwxr-xr-x. 2 root root 4096 Nov 9 2022 /etc/sddm.conf.d drwxr-xr-x. 2 root root 4096 Oct 8 2021 /etc/sensors.d drwxr-x---. 2 root root 4096 Apr 4 2023 /etc/sudoers.d drwxr-xr-x. 2 root root 4096 Jul 17 2021 /etc/supervisord.d drwxr-xr-x. 2 root root 4096 Sep 23 20:25 /etc/sysctl.d drwxr-xr-x. 2 root root 4096 Sep 23 20:25 /etc/tmpfiles.d drwxr-xr-x. 2 root root 4096 Oct 9 2021 /etc/xinetd.d drwxr-xr-x. 2 root root 4096 Apr 28 2023 /etc/yum.repos.d
$ ls -l /etc/cron.d total 8 -rw-r--r--. 1 root root 128 Apr 6 2024 0hourly -rw-r--r--. 1 root root 108 May 22 2024 raid-check
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Modified: 2017-09-28T12:59 User: Guest Check: HTML CSSEdit History Source |
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