TweetFollow Us on Twitter

Integrating OS X With OpenLDAP/Samba, Part 3

Volume Number: 25
Issue Number: 03
Column Tag: Networking

Integrating OS X With OpenLDAP/Samba, Part 3

Configuring Your Mac To Work With Linux Samba and LDAP Servers

by Noah Gift

Introduction

In the last two articles, we got familiar with using virtualization to build a Samba /LDAP environment that our Macs could talk to. For many people those two articles would be enough to setup a simple home file sharing and authentication system. And because our Ubuntu virtual machine is just a file, it is simple to keep copies of this configuration laying around in case something goes wrong.

In part two we reached a stopping point after we got basic authentication working with OpenLDAP. In this article we tackle how to fully configure and tweak OS X to work with OpenLDAP, and Samba, including automounting a network home directory via Samba or NFS served out from the virtual machine. It is almost a little too science fiction to talk about without seeing some examples, so I have included quite a few.

In the first two articles, we downloaded a pre-configured Ubuntu virtual machine here: http://examples.oreilly.com/9780596515829/vm/

All of the following steps will be based on the assumption that you have been continuing to work from either this Samba/OpenLDAP server, or a similar one you configured.

Getting Used to Automounting with Leopard

OS X has been around for almost a decade, with first version OS X server coming out in 1999. Many Systems Administrators have wrestled with trying to get OS X to behave more like Unix and Linux for all of this time. With 10.4 Tiger, a few changes brought OS X very close to acting like traditional Unix machines, and finally with Leopard becoming POSIX and SUSv3 compliant.

One of the new, and welcome, changes is a working automounting system just like your favorite Unix or Linux system. To demonstrate how useful this is, we are going to go back to our virtual machine to create an NFS exported file system, and then automount it on our Mac.

Step 1: Install NFS on the Ubuntu virtual machine:

sudo apt-get install nfs-kernel

(Note, if you are not familiar with the apt-get command on Ubuntu, it is a package installer, that works a lot like Fink or Mac Ports on the Mac)

Step 2: Add an entry into /etc/exports (again, on the virtualized server)

#directory exported      host(options)
/usr/export         *(rw,sync,insecure)

(Note, we are using * instead of specifying a host or range of IP addresses. This is insecure and exports the volume to the world. This is not recommended unless you are testing a configuration behind a firewall. Also, note that we use the option "insecure". This is because OS X uses a different port than Linux to communicate over NFS. If this option is not set on the server, an OS X client will not be able to mount a NFS volume without a special client side NFS configuration.)

Step 3: Back on the OS X machine, browse to /net/192.168.1.200/usr/export (or whatever the IP address is)

# cd /net/192.168.1.200/usr/export/

This is the beauty of automounting. You simply browse to a hostname/ip address, and the shares just mount. We can see this in action by looking at the output of the df command:

# df -h
Filesystem                  Size   Used  Avail Capacity  Mounted on
/dev/disk0s2                93Gi   81Gi   12Gi    88%    /
devfs                      110Ki  110Ki    0Bi   100%    /dev
fdesc                      1.0Ki  1.0Ki    0Bi   100%    /dev
map -hosts                   0Bi    0Bi    0Bi   100%    /net
map auto_home                0Bi    0Bi    0Bi   100%    /home
trigger                      0Bi    0Bi    0Bi   100%    /net/192.168.1.200/usr
trigger                      0Bi    0Bi    0Bi   100%    /net/192.168.1.200/usr/export
192.168.1.200:/usr/export  2.0Gi  461Mi  1.4Gi    25%    /net/192.168.1.200/usr/export

Step 4: Try to create a file

# touch foo
touch: foo: Permission denied

We get permission denied because NFS uses two levels of security. The first layer of security is host/ip based. We passed that layer of security, and were able to mount the volume. The reason we can't write to the file though, is that owner/group permissions are not set to allow my user account to write. Let's fix this now.

Creating LDAP/Samba Accounts for Mac on a Linux Server

In the last section we were able to setup a NFS server and mount it on our client, but we weren't able to write to it yet because we didn't have proper permission. Let's fix this, by creating a LDAP/Samba User account, and then changing permissions so we write to on when we automount it on the Mac.

Step 1: Use the smbldap-useradd command to create a mactech account

$ sudo smbldap-useradd mactech

Step 2: Use the smbldap-passwd command to set the password

$ sudo smbldap-passwd mactech
Changing UNIX password for mactech
New password: 
Retype new password: 

Step 3: Verify the account works

py4sa@py4sa:~$ su - mactech
Password: 
mactech@py4sa:~$ pwd
/home/mactech
mactech@py4sa:~$ id
uid=30003(mactech) gid=513(Domain Users) groups=513(Domain Users)

This command-line tool creates an account that simultaneously is able to authenticate to Samba, and LDAP. Now, we can go back to our exported volume, and change the ownership to reflect a uid(user id) of 30003, and a gid(group user id) of 513. Note, that the group is called Domain Users, which is a default Samba/LDAP group. All new user accounts get added to this account.

Step 4: Changing ownership of /usr/export to our new mactech user

mactech@py4sa:~$ exit logout py4sa@py4sa:~$ sudo chown -R 30003:513 /usr/export/ [sudo] password for py4sa:

Now, let's test this out on the Mac by changing to our newly created mactech user, and attempting to write to this automounted volume.

Step 5: Authenticating, Mounting, and Writing as an Samba/LDAP user. This takes place on your client OS X machine.

Change to the mactech user:

# su mactech
Password:
bash: /home/mactech/.bashrc: Input/output error

Enter the export directory and set off the automount:

bash-3.2$ cd /net/192.168.1.200/broadcasthost/localhost/
bash-3.2$ cd /net/192.168.1.200/usr/export/

List the contents of the directory:

bash-3.2$ ls
foo

Create a new file in this directory:

bash-3.2$ touch test.txt

No error, so list the contents again:

bash-3.2$ ls -la
total 31
drwxr-xr-x  3 mactech  Domain Users  4096 Nov  5 13:34 .
dr-xr-xr-x  3 root     wheel            2 Nov  5 12:21 ..
-rwxrw-rw-  1 mactech  Domain Users  6148 Oct 14 02:40 .DS_Store
drwxr-xr-x  2 mactech  Domain Users  4096 Oct 14 02:06 foo
-rw-r--r--  1 mactech  Domain Users     0 Nov  5 13:34 test.txt

There are a couple of things to point out. First, our shell complained when we logged into the mactech user, because there is no home directory path that matches /home/mactech on our Mac, like it does on the Ubuntu machine. We are going to fix that in the next section, but for now, if we move past this, we can see that yes, we can create a test file. And, if we look at the permissions, they are set to the username and group that we would expect. Ok, on to fixing the home directory.

Cross Platform Linux/Mac NFS Automounted Home Directory

In both the last article, and this article, we ran into problems when using LDAP user accounts, because when we created a user account in LDAP on the linux machine, the path to mount the home directory didn't exist on our Macs. In addition, it makes sense that we would want to share common network mounted home directories between the two platforms.

Fortunately, with a little help from symbolic links, it is quite easy to accomplish a cross platform home directory.

Step 1: Create a home directory in /net/192.168.1.200/usr/export/

While still logged in as the mactech user:

$ mkdir -p /net/192.168.1.200/usr/export/home/mactech

Step 2: On the Ubuntu server create symbolic link from /usr/export to /export

py4sa@py4sa:/$ sudo ln -s /usr/export/ /export

This allows us to create a common path to a home directory that we can also symbolically link on the Mac when it is mounted.

Step 3: Change the LDAP record for mactech to reflect the new location

py4sa@py4sa:/$ sudo smbldap-usermod -d /export/home/mactech mactech

Step 4: Create a symbolic link on OS X from the automount directory to /export

# sudo ln -s /net/192.168.1.200/usr/export /export

Step 5: Log in via the command line to the mactech account on OS X to verify it works, and verify the mount point.

# su - mactech
Password:
$
$ pwd
/export/home/mactech
$ df -h
Filesystem                  Size   Used  Avail Capacity  Mounted on
/dev/disk0s2                93Gi   80Gi   13Gi    87%    /
devfs                      111Ki  111Ki    0Bi   100%    /dev
fdesc                      1.0Ki  1.0Ki    0Bi   100%    /dev
map -hosts                   0Bi    0Bi    0Bi   100%    /net
map auto_home                0Bi    0Bi    0Bi   100%    /home
trigger                      0Bi    0Bi    0Bi   100%    /net/192.168.1.200/usr
trigger                      0Bi    0Bi    0Bi   100%    /net/192.168.1.200/usr/export
192.168.1.200:/usr/export  2.0Gi  461Mi  1.4Gi    25%    /net/192.168.1.200/usr/export

Ah, everything works this time. Now, let's make a test file just to be sure.

Step 6: Creating a test file

$ touch mycommondir.txt
$ ls -lan   
total 16
drwxr-xr-x  2 30003  513  4096 Nov  5 14:50 .
drwxr-xr-x  3 30003  513  4096 Nov  5 13:36 ..
-rw-r--r--  1 30003  513     0 Nov  5 15:10 mycommondir.txt

When we login to the Linux machine, we should see this same file and have access to it because the uid/gid are the same between the systems. Before we do that though, let's use fast user switching to login to this NFS mounted network account. After all this is a Mac, not just a command line only Operating System.

Step 7: Use fast user switching to login to the mactech account, and verify it works. (Note, using fast user switching is important because you need to keep your virtual machine running).

Your Mac should take a few seconds, and then you should get a home directory that looks like this:


Figure 1: NFS Mounted Mac Home Directory

What is cool about this, is that it automatically created "Mac stuff" for us, including the Desktop, Pictures, Downloads, and Library folder, yet kept the test file we created mycommondir.txt. Now when you are ready to log out of this account, we can test what happens when we ssh into our virtual machine as the mactech user. Want to guess what we see?

Step 8: ssh into Virtual Machine as mactech user

$ ssh mactech@192.168.1.200
mactech@py4sa:~$ pwd
/export/home/mactech
mactech@py4sa:~$ ls -lan
total 144
drwxr-xr-x  8 30003 513  4096 2008-11-05 15:28 .
drwxr-xr-x  3 30003 513  4096 2008-11-05 13:36 ..
drwx------  2 30003 513  4096 2008-11-05 15:14 Desktop
drwx------  2 30003 513  4096 2008-11-05 15:12 Downloads
-rw-r--r--  1 30003 513  6148 2008-11-05 15:14 .DS_Store
drwx------ 12 30003 513  4096 2008-11-05 15:15 Library
-rw-r--r--  1 30003 513  4096 2008-11-05 15:14 ._mactech_home_dir.png
-rw-r--r--  1 30003 513 98015 2008-11-05 15:14 mactech_home_dir.png
-rw-r--r--  1 30003 513     0 2008-11-05 15:10 mycommondir.txt
drwxr-xr-x  3 30003 513  4096 2008-11-05 15:13 Pictures
drwx------  3 30003 513  4096 2008-11-05 15:12 .Spotlight-V100
drwx------  2 30003 513  4096 2008-11-05 15:28 .ssh
mactech@py4sa:~$ 

Awesome! We have a common NFS mounted home directory that "just works" on OS X and Linux, and we did it all with a virtual machine.

Conclusion

In this third of a four-part series, we created a common NFS mounted home directory by leveraging the power of LDAP, Linux, NFS and the automount daemon. As a result, we now have a recipe for a complete cross platform authentication and network home directories.

Because we used an LDAP/Samba configuration that was configured to work together, we are able to create Samba shares that work with Linux, OS X, or Windows. These could be home directories, and common mount points via Samba, or you could do as we demonstrated in this article, and share out the same directory via Samba and NFS.

The beauty of this configuration is its flexibility, as we can use this one virtual machine to accomplish several different, yet robust configurations. In addition, due to the use of symbolic links, and the automounter, we didn't need to touch LDAP on OS X, other then our initial work in the second article. One thing we didn't cover in detail that bares a mention though, is that NFS requires a thorough understanding of Unix permissions. If you run into problems deploying this in a wider environment, remember to review that you have intentionally configured a proper umask, and group and user permissions. This is the most common problem when first dealing with common NFS home directories for first-timers.

In the final article, we will close the gaps of dealing with LDAP and Samba on OS X. We will briefly talk about OS X's extended attributes and Managed Preferences, and then get into configuring a project management and version control tool, trac, to work with LDAP. We will also briefly talk about how LDAP works with Apache authentication, and how the PHP LDAP admin tool can make dealing with LDAP much easier. Remember, all of this works with the exact same username and password, too, and that is the fun part of setting up centralized authentication.

BIBLIOGRAPHY AND REFERENCES

Noah Gift. "How To Build A Dirt Easy NAS with Samba". Red Hat Magazine, http://www.redhatmagazine.com/2007/06/26/how-to-build-a-dirt-easy-home-nas-server-using-samba/.

Noah Gift and Grig Gheorghiu "LDAP Crud". IBM Developerworks, http://www.ibm.com/developerworks/aix/library/au-ldap_crud/.

Noah Gift. "Getting Started With Open Directory". O'Reilly. http://www.macdevcenter.com/pub/a/mac/2007/06/01/discover-the-power-of-open-directory.html

Noah Gift and Jeremy Jones. "Python For Unix and Linux Systems Administration". O'Reilly . ISBN: 0596515820


Noah Gift has been a Mac user since his family bought a Macintosh Performa 6300 in 1992, and started connected to BBS networks immediately and then eventually the World Wide Web in 1993 when it become open to the public. He is the co-author of "Python For Unix and Linux System Administration" by O'Reilly, and the upcoming "Google App Engine In Action" by Manning.

Noah has a couple of decades of experience in the Television and Film industry starting off as an editor for ABC Network News as a teenager. He contributed to the first feature animated film for Disney Feature Animation and Sony Imageworks. He also had stints at Turner Studios and Caltech, where he worked for the Nobel Prize-winning President as a Mac expert. He has a Master's degree in CIS, and is LPI and ACSA certified. He currently works for WetaDigital in New Zealand. Many of his projects and writing are available at www.noahgift.com. He can be contacted at noah.gift@giftcs.com

 

Community Search:
MacTech Search:

Software Updates via MacUpdate

BBEdit 11.6.4 - Powerful text and HTML e...
BBEdit is the leading professional HTML and text editor for the Mac. Specifically crafted in response to the needs of Web authors and software developers, this award-winning product provides a... Read more
beaTunes 4.6.12 - Organize your music co...
beaTunes is a full-featured music player and organizational tool for music collections. How well organized is your music Library? Are your artists always spelled the same way? Any R.E.M. vs REM?... Read more
Tinderbox 7.0.1 - Store and organize you...
Tinderbox is a personal content management assistant. It stores your notes, ideas, and plans. It can help you organize and understand them. And Tinderbox helps you share ideas through Web journals... Read more
FotoMagico 5.4 - Powerful slideshow crea...
FotoMagico lets you create professional slideshows from your photos and music with just a few, simple mouse clicks. It sports a very clean and intuitive yet powerful user interface. High image... Read more
Direct Mail 4.3.9 - Create and send grea...
Direct Mail is an easy-to-use, fully-featured email marketing app purpose-built for OS X. It lets you create and send great looking email campaigns. Start your newsletter by selecting from a gallery... Read more
Tinderbox 7.0.1 - Store and organize you...
Tinderbox is a personal content management assistant. It stores your notes, ideas, and plans. It can help you organize and understand them. And Tinderbox helps you share ideas through Web journals... Read more
Direct Mail 4.3.9 - Create and send grea...
Direct Mail is an easy-to-use, fully-featured email marketing app purpose-built for OS X. It lets you create and send great looking email campaigns. Start your newsletter by selecting from a gallery... Read more
FotoMagico 5.4 - Powerful slideshow crea...
FotoMagico lets you create professional slideshows from your photos and music with just a few, simple mouse clicks. It sports a very clean and intuitive yet powerful user interface. High image... Read more
beaTunes 4.6.12 - Organize your music co...
beaTunes is a full-featured music player and organizational tool for music collections. How well organized is your music Library? Are your artists always spelled the same way? Any R.E.M. vs REM?... Read more
Spotify 1.0.49.125. - 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

The best sales on the App Store this wee...
The App Store has quite an exciting lineup of discount games this week that range across a variety of genres. It's a great opportunity to catch up on some of the premium games you may have been holding off on -- and some you can even grab for free... | Read more »
The best new games we played this week
Ah, here we are again at the close of another busy week. Don't rest too easy, though. We had a lot of great new releases in mobile games this week, and now you're going to have to spend all weekend playing them. That shouldn't be too much of a... | Read more »
Rollercoaster Tycoon Touch Guide: How to...
| Read more »
Rabbids Crazy Rush Guide: How to unlock...
The Rabbids are back in a new endless running adventure, Rabbids Crazy Rush. It's more ridiculous cartoon craziness as you help the little furballs gather enough fuel (soda) to get to the moon. Sure, it's a silly idea, but everyone has dreams --... | Read more »
Tavern Guardians (Games)
Tavern Guardians 1.0 Device: iOS Universal Category: Games Price: $2.99, Version: 1.0 (iTunes) Description: Tavern Guardians is a Hack-and-Slash action game played in the style of a match-three. You can experience high pace action... | Read more »
Slay your way to glory in idle RPG Endle...
It’s a golden age for idle games on the mobile market, and those addictive little clickers have a new best friend. South Korean developer Ekkorr released Endless Frontier last year, and players have been idling away the hours in the company of its... | Read more »
Tiny Striker: World Football Guide - How...
| Read more »
Good news everyone! Futurama: Worlds of...
Futurama is finding a new home on mobile in TinyCo and Fox Interactive's new game, Futurama: Worlds of Tomorrow. They're really doing it up, bringing on board Futurama creator Matt Groening along with the original cast and writers. TinyCo wants... | Read more »
MUL.MASH.TAB.BA.GAL.GAL (Games)
MUL.MASH.TAB.BA.GAL.GAL 1.0 Device: iOS Universal Category: Games Price: $2.99, Version: 1.0 (iTunes) Description: ENDLESS UPGRADES. CONSTANT DANGER. ANCIENT WISDOM. BOUNCY BALLS. Launch Sale, 40% OFF for a very limited time!!! MUL.... | Read more »
Dungeon Rushers (Games)
Dungeon Rushers 1.0 Device: iOS Universal Category: Games Price: $4.99, Version: 1.0 (iTunes) Description: Dungeon Rushers is a 2D tactical RPG combining dungeon crawler’s gameplay and turn based fights. Manage your team, loot dusty... | Read more »

Price Scanner via MacPrices.net

13-inch 2.0GHz Apple MacBook Pros on sale for...
B&H has the non-Touch Bar 13″ 2.0GHz MacBook Pros in stock today and on sale for $100 off MSRP. Shipping is free, and B&H charges NY sales tax only: - 13″ 2.0GHz MacBook Pro Space Gray (... Read more
15-inch Touch Bar MacBook Pros on sale for up...
B&H Photo has the new 2016 15″ Apple Touch Bar MacBook Pros in stock today and on sale for up to $150 off MSRP. Shipping is free, and B&H charges NY sales tax only: - 15″ 2.7GHz Touch Bar... Read more
12-inch Retina MacBooks on sale for $1150, $1...
B&H has 12″ 1.1GHz Retina MacBooks on sale for $150 off MSRP. Shipping is free, and B&H charges NY sales tax only: - 12″ 1.1GHz Space Gray Retina MacBook: $1149 $150 off MSRP - 12″ 1.1GHz... Read more
Apple restocks refurbished 11-inch MacBook Ai...
Apple has Certified Refurbished 11″ MacBook Airs (the latest models recently discontinued by Apple), available for up to $170 off original MSRP. An Apple one-year warranty is included with each... Read more
Apple Park Opens to Employees in April With T...
Apple has announced that Apple Park, the company’s new 175-acre campus, will be ready for employees to begin occupying in April. The process of moving more than 12,000 people will take over six... Read more
Manhattan Neighbors for Safer Telecommunicati...
A new education and advocacy group focused on cell phone and wireless risks, Manhattan Neighbors for Safer Telecommunications, launched today at http://www.ManhattanNeighbors.org. Manhattan... Read more
Portable Dual DisplayPort Monitor Dock Enable...
IOGEAR has announced the launch of its USB-C Dual DisplayPort Monitor Portable Dock (GUC3CMST). The dock enables users to easily connect two DisplayPort monitors to a USB-C or Thunderbolt 3 laptop to... Read more
13-inch 2.7GHz Retina MacBook Pro on sale for...
Amazon.com has restocked the 13″ 2.7GHz/128GB Retina MacBook Pro (MF839LL/A) for $200 off MSRP including free shipping: - 13″ 2.7GHz/128GB Retina MacBook Pro: $1099 $200 off MSRP This model tends to... Read more
Apple’s New iPad Ads Don’t Address Pro Users’...
Apple launched a new tranche of iPad Pro TV ads last week addressing actual queries and challenges from the Twitterverse, albeit using actors for the visuals. That’s great. As an iPad fan and heavy... Read more
Free Verbum Catholic Bible Study App For iOS
The Verbum mobile app runs on Logos’ powerful Bible software and is an advanced resource for mobile Catholic study. The Verbum app surrounds the Bible with the Tradition. Verbum comes with 15 free... Read more

Jobs Board

*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
*Apple* Retail - Multiple Positions- Chicago...
SalesSpecialist - Retail Customer Service and SalesTransform Apple Store visitors into loyal Apple customers. When customers enter the store, you're also the Read more
Manager *Apple* Systems Administration - Pu...
Req ID 3315BR Position Title Manager, Apple Systems Administration Job Description The Manager of Apple Systems Administration oversees the administration and 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
Manager *Apple* Systems Administration - Pu...
Req ID 3315BR Position Title Manager, Apple Systems Administration Job Description The Manager of Apple Systems Administration oversees the administration and Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.