The ability to customize the OpenBSD installation through siteXY.tgz install sets has been available for years, I just haven't given it much thought until now. I have several "build" machines that I often upgrade to the latest snapshot to work on. Every once in a while, I like to do a fresh, clean install. Each time, I have to manually tweak 50 different minor settings to get my working environment back to normal.

To simplify the process, I recently looked at using siteXY.tgz.

Using the information in the FAQ, I put together a site42-build.tgz ("build" being the name of the box I'm installing and "42" refers to the OpenBSD version I'm installing) that contained: /etc/ssh/ssh_host* files, /etc/mk.conf, /etc/rc.local, /etc/profile, directories for NFS mount points and an install.site script.

For generic site-specific install sets, name the tarball "siteXY.tgz". For host-specific install sets, name the tarball "siteXY-$(hostname -s).tgz" (taking the hostname entered during installation). Both sets will be displayed (when copied to your local FTP mirror) with the other install sets during installation and the host-specific set will be pre-selected.

My install.site script (which goes in the root of the siteXY tarball) appends /etc/fstab with NFS mount entries, creates my user account, installs necessary packages, appends /etc/sudoers giving wheel access. The install.site script is only a shell script (make it executable), so what can be done with it is virtually limited by your imagination. Here is my script:

## Add ccd configuration for alpha
if [ `cat /etc/myname` = "pw500.my.domain" ]; then
echo "==> Configuring ccd for /usr/obj"
cat << __CCD >> /etc/ccd.conf
ccd0    32      none    /dev/sd1a /dev/sd2a
__CCD
cat << __FSTABCCD >> /etc/fstab
/dev/ccd0a /usr/obj ffs rw,softdep,nodev,nosuid,noatime,softdep 1 2
__FSTABCCD
fi

## Add NFS mounts to fstab
echo "==> Adding NFS mounts to fstab"
cat << __FSTAB >> /etc/fstab
nfsserv:/cvs /cvs nfs rw,-b,-i 0 0
nfsserv:/home/mike /home/mike nfs rw,-b,-i 0 0
nfsserv:/home/software /home/software nfs ro,-b,-i 0 0
nfsserv:/usr/ports /usr/ports nfs rw,-b,-i 0 0
__FSTAB

## Install NUT if not buildsnap
if [ `cat /etc/myname` != "buildsnap.my.domain" ]; then
  echo "==> Installing nut"
  PKG_PATH=ftp://ftpserv/pub/OpenBSD/snapshots/packages/`arch -s`/ \
    /usr/sbin/pkg_add -x nut > /dev/null
  [ $? != 0 ] && echo Error: nut could not be installed.
fi

## Add wheel to sudoers
echo "==> Setting up /etc/sudoers"
cat << __SUDO >> /etc/sudoers
Defaults:%wheel !env_reset
%wheel  ALL=(ALL) NOPASSWD: SETENV: ALL
__SUDO

## Add mike user account, group and home directory (which is NFS mounted)
echo "==> Adding 'mike' user"
groupadd -g 10000 cvs
groupadd -g 1000 mike
useradd -g mike -u 1000 -L staff -s /bin/ksh -c 'Michael Erdely' \
  -p 'MYENCRYPTEDPASSHERE' \
  -G wheel,wsrc,cvs -d /home/mike mike

The install.site (or upgrade.site) script runs at the very end of the installation (or upgrade) process. Then, you're immediately prompted with the "Congratulations" message.

Be sure to read the FAQ entry for more information and submit your Stupid User Tricks.