sxxu - siteXX utility - a tool to help build OpenBSD siteXX files

This was inspired by siteXYtools from mongers.org, but it seemed like it
needed a few additional features to make it easier to do more common tasks.


For more information on siteXX files see:
http://www.openbsd.org/faq/faq4.html#site


The goals of sxxu are to help you:
* Keep configuration for your systems in a source control
* Recover from a disaster more quickly
* Do a matching install on a secondary system so you can
  o Upgrade between versions of OpenBSD with the ability to revert
  o Replace aging hardware
  o Build a test environment before pushing changes to a production system

sxxu is meant to be a simple utility for installing systems.  It does not have
the ability to continue to push changes out to already installed systems.  For
that functionality there are many more powerful solutions.  I do wonder if it
would be possible to patch sysmerge to support some way of migrating these
files.

Some of the problems sxxu tries to solve:
* duplication of common configuration for each system
* permissions easily get broken when configuration is in source control


USAGE: sxxu [-kmR] [-w WRKDIR]  [machine1 [machine2 [...]]]
  -k : Keep WRKDIR
  -m : rebuild mtree files
  -R : don't Recurse into Roles
  -w : specify the WRKDIR


DETAILS:

In the basedir, each directory is considered a "role", the common directory is
merged into each role by default and any directory named role-* does not
generate a tgz by default.

Any of the directory structure not in the siteXX directory is treated as a
normal siteXX that will extract to the root of your system after the install.  

Special files are kept in the siteXX directories.  These special files are
processed by the install.sxxu after install.

If a role/install.site exists, this WILL overwrite the install.sxxu that
would have processed these special files.

Create a directory structure for your system:

basedir/
 |-common
 |---siteXX
 |-machine1
 |---siteXX
 |-machine2
 |---etc
 |---siteXX
 |-role-imap
 |---siteXX
 |---var
 |-----sendmail


Special files and directories inside the siteXX directory:
    roles: 
      Contains a list of "roles" (directories in the basedir) to merge into
      this configuration.  The common directory is automatically included in
      all configurations.

    mtree: 
      An mtree(8) spec file for permissions on the files in this role. It gets
      applied before the files are put into the archive. See below for notes
      on how to create and update.

    siteXXrc: xxx
      A ksh script that is included before running the *_list commands and
      the individual install.site files for each role.  

    pkg_path:
      A list (one per line) of sites to add to the PKG_PATH environment.

    *_list:
      A list of arguments to commands to be run.  For example if pkg_add_list
      containing "rsync nrpe check_hw_sensors" will attempt to run 
      pkg_add rsync nrpe check_hw_sensors.

      The command is executed for each line of the file.

      You can set environment variables in the siteXXrc file for arguments.
      Setting "pkg_add_args='-i'" in a siteXXrc would make the above command
      pkg_add -i rsync nrpe check_hw_sensors

    patches/:
        All patches in this dir need to be relative to the root of the system
        where the tgz was extracted.

    packages/:
        Package files that will get installed.  Completely separate from
        pkg_add_list above.  It does inherit pkg_path and pkg_add_args.

    install.site:
        Your script that gets run after all the above things have been done. 

MTREE:

You can use sxxu -m to generate mtree spec files.  This will generate the
files with the permissions that are gotten after copying and applying the
existing mtree file. 

You can get some more advanced features with some other switches.

  # sxxu -kRw /tmp/sxxu-work

will extract all roles including those named role-* into /tmp/sxxy-work
without following the included roles.  At that point you can change
permissions in the work directory as you see fit, then when you are ready,
from the place where your source files are you would run

  $ sxxu -mw /tmp/sxxu-work

which will regenerate the mtree specs with the permissions you have set.