Patch OpenBSD bsd.rd with auto_install.conf & rc.firsttime

This is a very simple script that is used to create custom installation cd's and bsd.rd images for OpenBSD to be used with online provides (such as Vultr) to deploy fully configured instances.

The script does the following:

• Downloads a bsd.rd image from an openbsd mirror
• Extracts the filesystem portion of the ramdisk
• Mount the filesystem
• Patch the filesystem with auto_install
• Put the filesystem back into bsd.rd
• Create a siteXX.tgz with rc.firsttime
• Create a bootable ISO with the modified bsd.rd and siteXX.tgz

In order to preserve size the auto install configuration uses the 1st http mirror and then uses the siteXX.tgz from the created CD. This way our CD and bsd.rd are almost the same size.

NOTE: The script is really at its infantry and there is no error checking implemented currently.

Using

• Clone the repo
• Change into the cloned repo and create a folder fs/
• Update auto_install.conf with a desired information about your specific install
• Place any files you want included into your images (usually install.site and rc.firsttime)

cp install.site fs/
mkdir fs/etc
cp rc.firsttime fs/etc

Refs

• https://www.openbsd.org/faq/faq4.html#site
• https://github.com/ajacoutot/aws-openbsd
• https://github.com/joyent/openbsd-kvm-image-builder
• https://eradman.com/posts/openbsd-vps-installation.html