TweetFollow Us on Twitter

MacEnterprise: Loco for Local MCX

Volume Number: 25 (2009)
Issue Number: 02
Column Tag: MacEnterprise

MacEnterprise: Loco for Local MCX

Using Apple's client-management settings on the Local machine. Following up on MCX

by Greg Neagle

Previously in MacTech...

In the November issue, we looked at getting started with MCX by using MCX records in the local directory service. We set some policies for the loginwindow using the Guest Computer object, verified they worked, and noted that the Accounts preference pane had certain controls grayed out to match our management settings.

Since local directory service entries in Leopard are simply plist files stored in /var/db/dslocal/nodes/Default, replicating MCX settings to multiple machines can be as simple as copying a few files.

Lod

Scalability and Modularity

If you are going to use the local directory service to store MCX data, you'll quickly discover that putting all your management settings into the Guest Computer object doesn't give you very much flexibility. If you want different groups of machines to have different management settings, you'll have to maintain multiple versions of /var/db/dslocalnodes/Default/computers/guest.plist, and mixing and matching management settings becomes tedious, as you'd have to create a version of the guest.plist for every needed combination of management settings.

A new feature of MCX in Leopard can help: Computer Groups. Prior to Leopard, MCX supported "Computer Lists", which were, unsurprisingly, lists of computers. Management settings could be applied to Computer Lists, which would then apply those settings to all computers in the list. The downside is that a given computer could be a member of only a single computer list at a time.

Leopard's new Computer Groups behave more like groups of users: a computer can be a member of multiple Computer Groups. This allows you to modularize your management settings. Create a Computer Group called "loginwindow" and apply all the loginwindow management to that Computer Group. Create another Computer Group called "screensaver" and apply your screensaver policies. If you want a machine to have both the "loginwindow" and "screensaver" policies, just add it to both Computer Groups. In this way, you can modularize your policy settings and mix and match them among machines. This approach even works if you are implementing MCX management in a traditional network directory environment.

Complications ensue

Perhaps now you're thinking, "Great! I'll create Computer Groups with my desired management settings, add the Guest Computer to each of those Computer Groups, and I'm all set!" Not so fast. There's a complication: even though Workgroup Manager allows you to add the Guest Computer account to a Computer Group, the MCX settings for the Computer Group are not applied to guest computers. So we'll need to use another way to take advantage of Computer Groups.

Use Workgroup Manager to connect to the local directory service as we did last time:


We will create a computer record that will represent the current local computer. Make sure you are working in the /Local/Default directory. Select the Computer accounts icon in the left pane, and click New Computer. Set the Name and Short Name to "local_machine", and click Save. You can leave all other fields empty.


You can now add this computer record to your Computer Groups:


We're not done yet - MCX still has no way to know that by "local_machine" you mean the current machine that this is running on. To do this, we have to add some data to the local_machine record.

MCX identifies machines by the MAC layer address of their en0 interface - this is usually the built-in Ethernet port, but in the case of a MacBook Air, this is the AirPort interface. Here's a way in the command-line to get this info:

root# ifconfig en0 | awk ' /ether/ {print $2}'
00:1b:63:93:8b:ac

So the MAC layer address for this machine is 00:1b:63:93:8b:ac. We can add that to the local_machine record like this:

root# dscl . -create /Computers/local_machine \
ENetAddress 00:1b:63:93:8b:ac

Checking our work:

root# dscl . read /Computers/local_machine
AppleMetaNodeLocation: /Local/Default
ENetAddress: 00:1b:63:93:8b:ac
GeneratedUID: 15BEE70A-A32D-4A33-B740-93CBE95F75A4
RecordName: local_machine
RecordType: dsRecTypeStandard:Computers

Note that the GeneratedUID will vary, as it is created when you create the computer record in Workgroup Manager.

To actually take advantage of this, we'll need to write a script that runs on each machine that modifies the local_machine record with the MAC layer address of the current machine. Here's a very simple version:

#!/bin/sh
MAC=`ifconfig en0 | awk ' /ether/ {print $2}'`
dscl . -create /Computers/local_machine ENetAddress $MAC

This script gets the current MAC layer address and updates the local_machine record accordingly. You'd want to implement this script as one that ran during startup. You could do this as part of a StartupItem, or use launchd.

Pulling it together

Now you have a computer object that corresponds to the local machine, and management settings attached to Computer Groups. To implement these management settings on another machine or machines, you need to copy to each machine:

  • /var/db/dslocal/nodes/Default/computers/local_machine.plist

  • The appropriate plists from /var/db/dslocal/nodes/Default/Computer Groups

  • Your startup script that modifies the local_machine record.

Testing and Troubleshooting

While testing your new MCX settings, you'll want to be aware of tools available to you so you can see which MCX settings have been applied to your machines. The easiest tool to use in Leopard is System Profiler. Under the Software section is a new Managed Client category. You can use this to see what preferences are being managed, and their source.


In the illustration, we can see that com.apple.TimeMachine's preference "DoNotOfferNew-DisksForBackUp" is set to "1", that this is applied "often", and these settings come from membership in the "timemachine" Computer Group.

Another tool is available at the command line: mcxquery. Prior to 10.5.3, mcxquery did not display proper results when MCX records were in the local directory service, but it now behaves as expected.

mcxquery -user shortname

will show you the effective MCX settings for the user on the current machine.

Conclusion and additional thoughts

In this series of articles, we've looked at ways of using the local directory service to implement MCX settings. This would be useful for environments that don't have Open Directory, and cannot or will not do schema extension for Active Directory or third-party LDAP directory services. Mac administrators can also use these techniques as a proof-of-concept for MCX client management, using the local directory service implementation as a prototype for what benefits your organization would realize by extending the schema on its existing directory services.

There are certainly applications of this concept outside the management of enterprise workstations. Parents could use Workgroup Manager to manage their children's user account and capabilities - a sort of Parental Controls on steroids. In another application, the author used MCX records in the local directory service to lock down a Mac used as an iTunes jukebox. Since you are using local records, you can experiment with various settings and not worry that what you try will affect other machines on your network.

If nothing else, taking advantage of local MCX records should lower the entry bar to using Apple's client management system. If you haven't been using MCX in the past, there is no excuse not to at least try it now, and see how it can help you better manage Macs in your organization and give your users a consistent user experience.


Greg Neagle is a member of the steering committee of the Mac OS X Enterprise Project (macenterprise.org) and is a senior systems engineer at a large animation studio. Greg has been working with the Mac since 1984, and with OS X since its release. He can be reached at gregneagle@mac.com.

 

Community Search:
MacTech Search:

Software Updates via MacUpdate

OmniGraffle 7.2.2 - Create diagrams, flo...
OmniGraffle helps you draw beautiful diagrams, family trees, flow charts, org charts, layouts, and (mathematically speaking) any other directed or non-directed graphs. We've had people use Graffle to... Read more
OmniGraffle Pro 7.2.2 - Create diagrams,...
OmniGraffle Pro helps you draw beautiful diagrams, family trees, flow charts, org charts, layouts, and (mathematically speaking) any other directed or non-directed graphs. We've had people use... Read more
OmniGraffle Pro 7.2.2 - Create diagrams,...
OmniGraffle Pro helps you draw beautiful diagrams, family trees, flow charts, org charts, layouts, and (mathematically speaking) any other directed or non-directed graphs. We've had people use... Read more
OmniGraffle 7.2.2 - Create diagrams, flo...
OmniGraffle helps you draw beautiful diagrams, family trees, flow charts, org charts, layouts, and (mathematically speaking) any other directed or non-directed graphs. We've had people use Graffle to... Read more
Spotify 1.0.44.100. - Stream music, crea...
Spotify is a streaming music service that gives you on-demand access to millions of songs. Whether you like driving rock, silky R&B, or grandiose classical music, Spotify's massive catalogue puts... Read more
Microsoft OneNote 15.29 - Free digital n...
OneNote is your very own digital notebook. With OneNote, you can capture that flash of genius, that moment of inspiration, or that list of errands that's too important to forget. Whether you're at... Read more
WALTR 2 2.0.8 - $39.95
WALTR 2 helps you wirelessly drag-and-drop any music, ringtones, videos, PDF, and ePub files onto your iPhone, iPad, or iPod without iTunes. It is the second major version of Softorino's critically-... Read more
Dropbox 16.3.27 - Cloud backup and synch...
Dropbox is an application that creates a special Finder folder that automatically syncs online and between your computers. It allows you to both backup files and keep them up-to-date between systems... Read more
EtreCheck 3.1.5 - For troubleshooting yo...
EtreCheck is an app that displays the important details of your system configuration and allow you to copy that information to the Clipboard. It is meant to be used with Apple Support Communities to... Read more
Carbon Copy Cloner 4.1.12 - Easy-to-use...
Carbon Copy Cloner backups are better than ordinary backups. Suppose the unthinkable happens while you're under deadline to finish a project: your Mac is unresponsive and all you hear is an ominous,... Read more

Latest Forum Discussions

See All

Track Santa with these three festive app...
Christmas is fast approaching and that means it's time to prepare for Santa's yearly pilgrimage around the globe. Christmas Eve is an exciting time as parents help their kids get ready to welcome Santa. You've got the cookies and milk all planned... | Read more »
Galaxy on Fire 3 and four other fantasti...
Galaxy on Fire 3 - Manticore brings the series back for another round of daring space battles. It's familiar territory for folks who are familiar with the franchise. If you've beaten the game and are looking to broaden your horizons, might we... | Read more »
The best apps for your holiday gift exch...
What's that, you say? You still haven't started your holiday shopping? Don't beat yourself up over it -- a lot of people have been putting it off, too. It's become easier and easier to procrastinate gift shopping thanks to a number of apps that... | Read more »
Toca Hair Salon 3 (Education)
Toca Hair Salon 3 1.0 Device: iOS Universal Category: Education Price: $2.99, Version: 1.0 (iTunes) Description: | Read more »
Winter comes to Darkwood as Seekers Note...
MyTona, based in the chilly Siberian city of Yakutsk, has brought a little festive fun to its hidden object game Seekers Notes: Hidden Mystery. The Christmas update introduces some new inhabitants to players, and with them a chance to win plenty of... | Read more »
Bully: Anniversary Edition (Games)
Bully: Anniversary Edition 1.03.1 Device: iOS Universal Category: Games Price: $6.99, Version: 1.03.1 (iTunes) Description: *** PLEASE NOTE: This game is officially supported on the following devices: iPhone 5 and newer, iPod Touch... | Read more »
PINE GROVE (Games)
PINE GROVE 1.0 Device: iOS Universal Category: Games Price: $1.99, Version: 1.0 (iTunes) Description: A pine grove where there are no footsteps of people due to continuous missing cases. The case is still unsolved and nothing has... | Read more »
Niantic teases new Pokémon announcement...
After rumors started swirling yesterday, it turns out there is an official Pokémon GO update on its way. We’ll find out what’s in store for us and our growing Pokémon collections tomorrow during the Starbucks event, but Niantic will be revealing... | Read more »
3 reasons why Nicki Minaj: The Empire is...
Nicki Minaj is as business-savvy as she is musically talented and she’s proved that by launching her own game. Designed by Glu, purveyors of other fine celebrity games like cult favorite Kim Kardashian: Hollywood, Nicki Minaj: The Empire launched... | Read more »
Clash of Clans is getting its own animat...
Riding on its unending wave of fame and success, Clash of Clans is getting an animated web series based on its Clash-A-Rama animated shorts.As opposed to the current shorts' 60 second run time, the new and improved Clash-A-Rama will be comprised of... | Read more »

Price Scanner via MacPrices.net

New 2016 13-inch Touch Bar MacBook Pros on sa...
B&H Photo the new 2016 Apple 13″ 2.9GHz/256GB Touch Bar MacBook Pros on sale for $50 off MSRP, each including free shipping plus NY sales tax only: - 13″ 2.9GHz/256GB Touch Bar MacBook Pro Space... Read more
12-inch 1.2GHz Space Gray Retina MacBook on s...
B&H Photo has dropped their price on the 2016 Apple 12″ 1.2GHz Space Gray Retina MacBook (MLH82LL/A) to $1399 including free shipping plus NY sales tax only. Their price is $200 off MSRP, and it’... Read more
Never Settle for Low Performing Wifi With iOS...
AppYogi Software has announced the release of WiFi Signal Strength Status App 1.0, the company’s new utility developed exclusively for macOS. WiFi Signal Strength Status App features a unique, single... Read more
New 2016 13-inch Touch Bar MacBook Pros in st...
B&H Photo has stock of new 2016 Apple 13″ Touch Bar MacBook Pro models, each including free shipping plus NY sales tax only: - 13″ 2.9GHz/512GB Touch Bar MacBook Pro Space Gray: $1999 - 13″ 2.... Read more
New 2016 15″ Touch Bar MacBook Pros in stock...
B&H Photo has new 2016 Apple 15″ Touch Bar MacBook Pro models in stock today including free shipping plus NY sales tax only: - 15″ 2.7GHz Touch Bar MacBook Pro Space Gray: $2799 - 15″ 2.7GHz... Read more
DietSensor App Targeting Diabetes and Obesity...
DietSensor, Inc., a developer of smart food and nutrition applications designed to fight diabetes and obesity and help improve overall fitness, has announced the launch of its DietSensor app for... Read more
Holiday 2016 13-inch 2.0GHz MacBook Pro sales...
B&H has the non-Touch Bar 13″ MacBook Pros in stock today for $50-$100 off MSRP. Shipping is free, and B&H charges NY sales tax only: - 13″ 2.0GHz MacBook Pro Space Gray (MLL42LL/A): $1449 $... Read more
Holiday sale: Apple TVs for $51-$40 off MSRP,...
Best Buy has dropped their price on the 64GB Apple TV to $159.99 including free shipping. That’s $40 off MSRP. 32GB Apple TVs are on sale right now for $98 on Sams Club’s online store. That’s $51 off... Read more
12-inch Retina MacBooks, Apple refurbished, n...
Apple has restocked a full line of Certified Refurbished 2016 12″ Retina MacBooks, now available for $200-$260 off MSRP. Refurbished 2015 models are available starting at $929. Apple will include a... Read more
Holiday sale: 12-inch Retina MacBook for $100...
B&H has 12″ Retina MacBooks on sale for $100 off MSRP as part of their Holiday sale. Shipping is free, and B&H charges NY sales tax only: - 12″ 1.1GHz Space Gray Retina MacBook: $1199 $100... Read more

Jobs Board

Integration Technician, *Apple* - Zones, In...
…at Zones and for our customers each day. Position Overview The Apple Integration Technician will be responsible for performing customer specific configuration Read more
*Apple* Brand Ambassador (Macy's) - The...
…(T-ROC), is proud of its unprecedented relationship with our partner and client, APPLE ,in bringing amazing" APPLE ADVOCATES"to "non" Apple store locations. Read more
*Apple* Retail - Multiple Positions- Trumbul...
Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, you're also the Read more
*Apple* Retail - Multiple Positions - Apple,...
Job Description: Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, Read more
US- *Apple* Store Leader Program - Apple (Un...
…Summary Learn and grow as you explore the art of leadership at the Apple Store. You'll master our retail business inside and out through training, hands-on Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.