This is a script made for my http-mirror/repo/iPXE guest to automatically detect any number of ISOs as they're attached/ejected and mount them to a directory on-demand.
It mounts them to a subdirectory taking after LABEL for easy recognition and presentation on a webserver frontend (e.g. /mywebroot/isos/Rocky-9-2-x86_64-dvd). It also removes the directories when an ISO is no longer present - aiming to only list ISOs mount dirs for those it has available at any given time.
As a general overview it installs two configuration files - One to autofs.master.d for its self-managed cdrom mounts, and another in udev.d to call the script whenever a CDROM event is detected.
When called it scans /dev/disk/by-label for CD's with a label and automounts them to their own subdirectory named after the label - In my case this is for easy zero-configuration HTTP mirroring access without consuming additional space or needing a process for every new random ISO I attach.
It helps me avoid:
- Wasting hypervisor storage space by extracting ISOs into guests.
- Bloating my guest virtual disk's because of the above (for backup purposes - Some of these ISOs are close to 10GB!).
- Doing the above manually on a per-ISO basis
- Managing autofs/fstab entries on a per-ISO basis (ANd manually removing stale mounts when the CD gets ejected too.)
This script solves these problems for me by making a mounted directory magically appear in the webserver of my repo/mirror guest after attaching it from the hypervisor without consuming any addutional space OR time to manually mount them.
I couldn't find a zero-configuration solution like this in the 68 seconds I spent searching online so I spent a lot longer making this script instead. Hopefully it's resourceful to others and perhaps even in other use-cases.
Run main and it'll place its autofs and udev configs then run. It will exit before doing anything if it doesn't think autofs is installed so make sure to install that first!
This script was written generically and will work on any modern distro (And perhaps even old ones) where autofs is available. It auto-detects the path to auto.master.d to handle subtle distro differences.
It was written for a Rocky 9.2 guest on VMware with Hot-added CD/DVD drive's and the eject command but also works tested on an Archlinux guest with QEMU, whose AUR autofs package uses a subdirectory of /etc.
I would expect this to also work on any physical servers with CD drives. This tool could also prove useful in other contexts.
-
Direct ISO directory support? Being able to point the script right at an ISO dir/mount and forget - would be nice. But monitoring for changes would require more than just udev event checks.
-
cdrom eject & hypervisor cdrom-drive removal check to avoid fighting/locking conditions on active mounts.