Mac OS X - Advanced Computer(Re)Name via MySQL (Extended)

No comments (condensed) version:
http://codesnippets.joyent.com/posts/show/2155

#!/bin/bash
# Script:   mysql_computername.sh
# Version:   1.0
# Description:  Rename computers dynamically on system startup.
#     Variables are pulled from a MySQL database for
#     easier management.
#
# Developed by:  Mark Carver © 2009
# Email:   mark_carver@jsd.k12.ak.us
# Website:   http://oldgreenhorn.blogspot.com

export PATH=${PATH}:/usr/local/mysql/bin

# MySQL Configuration
mysql_host='localhost'    # Domain, IP
mysql_user='ReadOnlyUser'    # Preferably use a user that only has read only access as the password
mysql_password='YoUrPaSsWoRd'  # is visible in this script.
mysql_db='database_name'
mysql_connection="mysql -s -N -w --connect_timeout=5 -h ${mysql_host} -u ${mysql_user} --password=${mysql_password} ${mysql_db}"

# Test for connection to host. Computer needs to start network connections on startup, otherwise this script would often fail.
# Time is calculated in minutes by multiplying the sleep (number of seconds it waits before trying again) and while loops 
# (number of loops it will complete before failing) then dividing by 60 (seconds).
# 10 seconds x 30 loops = 300 seconds / 60 seconds = 5 minutes
i=0
while [ $i -lt 30 ]
do
    if eval "ping -c 1 -q ${mysql_host}"; then
  internet='connected'
        break
    else
      sleep 10
  let i+=1
    fi
done

if [ "${internet}" == 'connected' ]; then
 
 # Test for connection to MySQL database. Read above for instructions on changing timout settings.
 m=0
 while [ $m -lt 30 ]
 do
  if eval "${mysql_connection} -e \"SHOW DATABASES\""; then
   mysql_status='connected'
   break
  else
   sleep 10
   let m+=1
  fi
 done

 if [ "${mysql_status}" == 'connected' ]; then

  # Pull variables from the MySQL server

  # ${template}: Naming scheme that allows you to dynamically change how the computer name is displayed.
  #     When storing the value in the MySQL database, you must use single quotes ( ' ) around
  #     any metacharacters ( |  & ; ( ) < > space tab) that is used in your naming scheme.
  #    Not doing so will break the script. -------------------See below for more details.
  template=`${mysql_connection} -e "SELECT value FROM settings WHERE attribute='template'"`

  # ${mac}:  Pulls the MAC address of this computer and searches for it on the MySQL database.
  #    It then parses out the ":" and changes the case from lower to UPPER. 00:1f:f3:d0:a5:60 > 001FF3D0A560
  #    You may need to modify this line to suit how you MAC addresses are stored in your database.
  #    To keep the colons (:) in, remove the following: | tr -d ':'
  #    To keep the case lower, remove the following:  | tr 'a-z' 'A-Z'
  mac=`ifconfig en0 | grep -o -E '([[:xdigit:]]{1,2}:){5}[[:xdigit:]]{1,2}' | tr -d ':' | tr 'a-z' 'A-Z'`
  # DEBUG:  Uncomment the line below and replace the MAC address with one that is currently in your
  #    MySQL database. This will allow you to run this script locally to smooth out any settings.
  #    Make sure you comment it back or remove the line before you deploy, otherwise you'll get a
  #    nasty surpise ;)
  mac="001FF3D0A560"
  
  # ${exists}: Checks the MySQL database for a record that matches the MAC address  
  exists=`${mysql_connection} -e "SELECT ethernet FROM computers WHERE ethernet='${mac}'"`
  
  if [ "${exists}" != '' ]; then
  
   ###############################################  Custom Variables ###############################################
   # Here is where you will create your own variables depending on what you wish to display for the computer name. #

   fas=`${mysql_connection} -e "SELECT fas FROM computers WHERE ethernet='${mac}'"`
   last_name=`${mysql_connection} -e "SELECT last_name FROM users WHERE fas='${fas}'"`
   first_name=`${mysql_connection} -e "SELECT first_name FROM users WHERE fas='${fas}'"`
   school=`${mysql_connection} -e "SELECT school FROM computers WHERE fas='${fas}'"`
   team=`${mysql_connection} -e "SELECT team FROM users WHERE fas='${fas}'"`
   cart=`${mysql_connection} -e "SELECT cart FROM computers WHERE fas='${fas}'"`
   slot=`${mysql_connection} -e "SELECT slot FROM computers WHERE fas='${fas}'"`
   if [ "${cart}" != "" ] && [ "${slot}" != "" ]
   then
    fas="${cart}${slot}-${fas}"
   fi
 
   if [ "${last_name}" != "" ] || [ "${first_name}" != "" ]; then
    lastname_first="- ${last_name}, ${first_name}"
   else
    lastname_first=""
   fi
   
   #                            #
   ############################################## End Custom Variables #############################################
 
   # Takes your MySQL template string and evaluates it to include the variables. Example of the value that's stored:
   #         ${school} ${team} ${lastname_first} '('${fas}')'
   # Any metacharacters will need to be put in single quotation. You must also put the EXACT variable for this to work.
   # Otherwise it will just spit out garbage.
   computer_name=`eval echo ${template}`
 
   # Takes the compiled computer name and condenses any extra spaces for variables that may have been blank.
   # Then formats the computer name to an appropriate LocalHostName with lower case, no metacharacters, and only one hyphen :) 
   computer_name=`echo ${computer_name} | tr -s " "`
   local_hostname=`echo ${computer_name} | tr -s "[:punct:]" "-" | tr -c -s '\12\60-\172' "-" | tr 'A-Z' 'a-z' | sed 's/-$//'`

   # And finally, we can safely set the computer name and local host name!
      scutil --set ComputerName "${computer_name}"
   scutil --set LocalHostName "${local_hostname}"
   exit 0  
  else
   logger -s "The MAC address: ${mac} does not exist in the database. Will try again next startup/login."
   exit 0
  fi
 else
  logger -s "MySQL connection timeout reached. Failed connecting to MySQL database: ${mysql_db} at ${mysql_host}. Will try again next startup/login."
 fi
else
 logger -s "Host connection timeout reached. Failed connecting to host: ${mysql_host}. Will try again next startup/login."
fi