Computer Services
Stanton/Wilmington Campus 
XP documentation and procedures
ainstall.kix

Background

Ainstall (app install) was historically used by our NT unattended install procedure. It got ugly pretty quickly. It would take an arg on the command like, parsed from a config file, and call a label inside the batch file to do a lot of stuff. Sysdiffs were all in the same dir and supporting files were scattered all over.

Design

Pat, who often gets to clean up my mistakes and/or make my ideas far more elegant, has suggested we make a general installation share point and a separate subdir for each install option and have NT and XP share the same install subdir. If needed, each can detect the installed OS and proceed differently (via applying different sysdiffs or scripts). Our "ainstall" program could then be a lot simpler, like almost just taking an arg and CDing into the proper install directory and calling a standard install.bat file inside each one.

Example:

\\server\install\apps\foobar

Under foobar could be a subdir for winnt and winxp for OS specific packages and in the top of foobar would be an install.bat file that figures out what to do as appropriate.

In addition, I'd like to add error checking to the install. Make our own HKLM reg key and scribble installed packages into there. ainstall would know the package option name from its arg -- like netscape), it would call the install.kix file in the package name's subdir, that package should do some sort of check to ensure everything got installed, and if so, scribble the package name and version into a regkey. If it didn't install, it should attempt some sort of error recovery (like reboot and try again for example...)

reg structure...

HKLM 
  \ Software
    \ DTCC
      \ Packages 
        \ PackageA
          \ Version  
            Date
            Time
            Login Info
      \ ainstall
        \ returnval
          bootcount 
          fresh
          final
          unattended
          

Each ainstall.kix script should have a list of other package dependencies in it and return a status string via the key:

HKLM\Software\DTCC\ainstall\returnval

returnval can be one of

• ok - Package already installed and tests ok
• done - Package installed OK
• reboot - Package installed OK, perform reboot before installing other packages
• fresh - Package requests it be first to be installed after a reboot, not installed, schedule a reboot
• fail - Package failed to install for some reason. ainstall will not increment pkgcount or sweepcount and increment skipcount. Hopefully a reboot will fix the problem and it will install next time.
• dependency - Name of package that must be installed before this one. Install not done. Note that install.kix may have several dependencies listed. It checks the install status of each one and then exits with this regkey set to first package it fines. Next sweep will invoke it again and it can recheck and return another dependency if appropriate.

With this in place, hopefully, we can just list packages needing to be installed in any order and list the rules in each install.kix file and the code should be smart enough to figure out what it needs to do. To do this, ainstall needs to maintain status info in reg keys or variables it can check. They are:

• pkgcount - regval - Count of packages installed ok during this boot session
• depcount - array variable - list of packages skipped due to a dependency failure. Each time we try to install a dependency, we check to see if it's already listed in this array. If so, we've detected a dependency loop and need to fail.
• sweepcount - variable - Number of times packages installed during this sweep. If we hit end of list and this value is above zero, we start scanning list from top again hoping to pick up a few more before having to reboot. If we get to end of list and sweepcount is zero and skipcount is not zero, we do a reboot. If we get to end of list and sweepcount is zero and skipcount is zero, we set the final regkey to 1 and reboot
• skipcount - variable - number of packages skipped during this boot session. If this is above zero at end of processing list, we increment loopcount and start the list from the top
• final - regval - If not zero, then this is final boot. Do any clean up, prevent further reboots, set default domain winlogon key to DTCC, autoadminlogoncount to zero, reboot.
• fresh - regval - A package requested to be installed first in the next reboot. Park that package's name here. On next reboot, check this key. Note that this only holds one value even though during a sweep there may be multiple packages that request to be done fresh. Doesn't matter, as long as one makes the grade at reboot time. They can overwrite or honor if a value exists. I don't think it makes a difference. It'll all sort itself out.
• bootcount - regval - A number of boots where no packages were installed. This is a failsafe to prevent infinite rebooting. If this value hits a set max times, we give up and list packages that failed to install and hold the install at that point.
• unattended - regval - set to true during an unattended install. At end of install (final phase) it should be removed. This key flags ainstall.kix that it is not invoked by a user. It is also checked when ainstall.kix determines its job is done. If true, it will do the final cleanups. If done by an end-user, it will just reboot the machine and not muck with the autologon key values.

package install.kix responsibilities

• Ensure that it doesn't exit before setting returnval. Best to blank out the key first just in case. The key will contain the previous packages value which we don't want to return by mistake.
• Know how to check if other packages it depends on exist and what to do if they don't (return the package needed in returnval)
• If it wants to be first install, know how to check pkgcount regkey to see if it is zero or not and if not zero, return fresh value
• If it requires a reboot after install (where no other packages should be installed after it), it should return reboot if it installs ok.

ainstall responsibilities

The ainstall.kix program itself will be invoked either by the unattended install (where it groks a list of packages out of a file) or by a sysop doing a single package install (where it uses a package list of just one.) This begs the question of what to do if a sysop invokes a package install with dependencies which aren't already installed. In this case, it'd be nice if ainstall would handle the dependencies as well and do the right thing.

So, basically, ainstall.cmd would live in the root of the install share and be invokable via sysop and ainstall.kix would live in the apps directory and be invoked only by the unattended logon process or via ainstall.cmd from the root.

So ainstall.kix needs to handle calling package install scripts in each directory, managing their return values, knowing when to reboot, and knowing when to finish up and clean up.

Main XP Unattended Install Doc Page