dockutil 1.0 released

As a Mac sysadmin, I’ve had the need to manipulate the dock on hundreds of systems at a time.

I used to cobble together terrible shell scripts to do the job, but now thanks to plistlib and python, plist manipulation is really easy. I am releasing this utility free under the Apache 2.0 license. Hopefully some other sysadmins will find it useful.

dockutil is a command line utility for managing Mac OS X dock items.
It can add, replace, list, move, find, and delete dock items. It supports Applications, Folders, Stacks, and URLs. It can act on a specific dock plist or every dock plist in a folder of home directories.
It is compatible with Mac OS X Tiger and Leopard.

Download dockutil here.

Here is the usage information:

usage: dockutil -h
usage: dockutil –add (path to item) | (url) [--label (label)] [ folder_options ] [ position_options ] [ plist_location_specification ]
usage: dockutil –remove (dock item label) [ plist_location_specification ]
usage: dockutil –move (dock item label) position_options [ plist_location_specification ]
usage: dockutil –find (dock item label) [ plist_location_specification ]
usage: dockutil –list [ plist_location_specification ]

position_options:
–replacing (dock item label name) replaces the item with the given dock label or adds the item to the end if item to replace is not found
–position [ index_number | beginning | end | middle ] inserts the item at a fixed position: can be an position by index number or keyword
–after (dock item label name) inserts the item immediately after the given dock label or at the end if the item is not found
–before (dock item label name) inserts the item immediately before the given dock label or at the end if the item is not found
–section [ apps | others ] specifies whether the item should be added to the apps or others section

plist_location_specifications:
(path to a specific plist) default is the dock plist for current user
(path to a home directory)
–allhomes attempts to locate all home directories and perform the operation on each of them
–homeloc overrides the default /Users location for home directories

folder_options:
–view [grid|fan|list|automatic] stack view option
–display [folder|stack] how to display a folder’s icon
–sort [name|dateadded|datemodified|datecreated|kind] sets sorting option for a folder view

Examples:
The following adds TextEdit.app to the end of the current user’s dock:
dockutil –add /Applications/TextEdit.app

The following replaces Time Machine with TextEdit.app in the current user’s dock:
dockutil –add /Applications/TextEdit.app –replacing ‘Time Machine’

The following adds TextEdit.app after the item Time Machine in every user’s dock on that machine:
dockutil –add /Applications/TextEdit.app –after ‘Time Machine’ –allhomes

The following adds ~/Downloads as a grid stack displayed as a folder for every user’s dock on that machine:
dockutil –add ‘~/Downloads’ –view grid –display folder –allhomes

The following adds a url dock item after the Downloads dock item for every user’s dock on that machine:
dockutil –add vnc://miniserver.local –label ‘Mini VNC’ –after Downloads –allhomes

The following removes System Preferences from every user’s dock on that machine:
dockutil –remove ‘System Preferences’ –allhomes

The following moves System Preferences to the second slot on every user’s dock on that machine:
dockutil –move ‘System Preferences’ –position 2 –allhomes

The following finds any instance of iTunes in the specified home directory’s dock:
dockutil –find iTunes /Users/jsmith

The following lists all dock items for all home directories at homeloc in the form: item(tab)path(tab)(section)tab(plist)
dockutil –list –homeloc /Volumes/RAID/Homes –allhomes

Notes:
When specifying a relative path like ~/Documents with the –allhomes option, ~/Documents must be quoted like ‘~/Documents’ to get the item relative to each home

Bugs:
Names containing special characters like accent marks will fail

Contact:
Send bug reports and comments to kcrwfrd at gmail.

Shell Injection with AppleScript’s do shell script

AppleScript’s do shell script capability is immensely useful, but if you are sending variable data to do shell script, always validate input and use quoted form of variableName. See the following example:

set dialogResult to (display dialog "Enter a directory name to pass to ls:" default answer ";say boo" buttons {"Cancel", "Quoted Form", "Raw"})

if button returned of dialogResult is “Quoted Form” then
try
set theCommand to “ls ~/” & quoted form of text returned of dialogResult
display dialog “Will execute:” & return & theCommand & return & “Proceed?”
do shell script theCommand
end try
else
try
set theCommand to “ls ~/” & text returned of dialogResult
display dialog “Will execute:” & return & theCommand & return & “Proceed?”
do shell script theCommand
end try
end if

Note you’ll have to fix the quotes to standard double quotes to get this to compile. I couldn’t get wordpress to cooperate.

Unix Environment Variable Scope/Security

I recently encountered a command line tool which exposed passwords in the process listing.

The command would also also accept a password as an environment variable. I was concerned with the security of storing a password in an environment variable.

This article at itworld.com does a nice job explaining environment variable scope.

Environment variables are only accessible in the shell in which they are set.

If you export the variable, it is accessible to any subshell of the shell in which it is exported. Simply logging in as another user on the system or even the same user does not allow access to the exported variable.

So, until someone corrects me, I believe that setting and exporting environment variables containing passwords in a script does protect the password from exposure. As soon as the command requiring the password has completed, the variable can be reset to an empty string to prevent any further access to the password.

PyAverager tutorial error with Cocoa Bindings

this class is not key value coding-compliant for the key numbersInput

If you are getting this error after doing the PyObjC averager tutorial called Using PyObjC for Developing Cocoa Applications with Python , import your class in main.py.

After the line:
import PyAveragerAppDelegate

add:
import Averager

This should allow the numbersInput variable to be properly bound to Interface Builder.

I found the solution on macosxhints forum here.

10.5 AD plugin slow logins related to macAddress query

The slow login times in the Leopard AD plugin seem to be related to a search by macAddress.  If you killall -USR1 DirectoryService, and login on a Leopard machine bound to AD, you’ll notice a query on macAddress in the /Library/Logs/DirectoryService/DirectoryService.debug.log. I am not sure the purpose of this query, but our computer objects don’t even use the macAddress attribute, so the query always results in no records found.

I can manually execute the same query and the time almost perfectly matches the delay I see with logins; about 45 seconds.

time ldapsearch -v -w password -x -h domaincontroller.domain.forest.com -D username@domain.forest.com -b "DC=domain,DC=forest,DC=com" "(&(objectCategory=cn=computer,cn=schema,cn=configuration,dc=forest,dc=com)
(macAddress=00:1a:22:ee:31:ac))”

Just substitute your own domain, forest, domain controller, username, password, and mac address etc to test.

I’ve tried manually mapping macAddress to another attribute, but it didn’t make a difference, so I don’t have any workaround to offer. Adding the macAddress attribute to your computer objects in AD might speed things up, but I have not tested this.  I’ve notified Apple of the issue in radar 5752763, which is marked as a Duplicate of 5679705.  If you see this macAddress query taking a long time, please report this to Apple so it can get fixed sooner rather than later.  Actually, this same query is used during the join process, which may explain the long join times while it searches for an existing computer.

rsync 3 report update

I’ve posted about my rsync experiences in the past.  And results of a prerelease of rsync 3. Anyway I’ve been doing some testing with the final release versions of rsync 3.

It does a good job.  With a couple of patches, it will even preserve file flags and creation times to pass every backup bouncer metadata test.

Unfortunately it is slow compared to the old rsyncx.  A job that took 1.5 hours with rsyncx takes about 6 hours with rsync 3 with extended attribute support turned on.   But that time is for syncing a couple terabytes of data, so if you aren’t comparing that much data, the performance hit won’t be as dramatic.

For a backup that passes the backup bouncer tests, we’ll have to deal with the speed trade off.  Plus rsync 3 is being actively updated and is already much more stable than any previous version of rsync for Mac OS X.

Bombich has already integrated it into Carbon Copy Cloner, and he has a nice updated guide for compiling it with the required patches.

Play mp3 from python on Mac

This site has a few nice little PyObjC samples.
One of them shows how to play a sound using AppKit’s NSSound. This is exactly what I was trying to do today.

And since PyObjC is built-in in 10.5, no addtional software is required.

Python is already batteries included, with PyObjC, you’ve got batteries galore.

ipython output:

In [1]: from AppKit import NSSound
In [2]: sound = NSSound.alloc()
In [3]: sound.initWithContentsOfFile_byReference_(’/System/Library/CoreServices/Setup Assistant.app/Contents/Resources/TransitionSection.bundle/Contents/Resources/intro-sound.mp3′, True)
Out[3]:
In [4]: sound.play()
Out[4]: True
In [5]: sound.stop()
Out[5]: True

waiting for root device: could be duplicate UUIDs

If you run into waiting for root device when booting in verbose mode or you get a flashing question mark, etc, it could be that your volumes have duplicate UUIDs. The UUID is the primary means that is used to locate the boot volume to root from. If you have duplicate UUIDs, your Mac may not be able to determine which volume to boot from. If you suspect this may be the case, boot from another disk or CD and run diskutil list to get a list of all volumes. Then run diskutil info on each to get the UUIDs. Check for duplicates.

kserver:~ pbuffer$ diskutil list
/dev/disk0
#: TYPE NAME SIZE IDENTIFIER
0: GUID_partition_scheme *74.5 Gi disk0
1: EFI 200.0 Mi disk0s1
2: Apple_HFS int_1 19.8 Gi disk0s2
3: Apple_HFS int_2 19.8 Gi disk0s3
4: Apple_HFS int_3 34.5 Gi disk0s4

kserver:~ pbuffer $ diskutil info disk0s2 | grep UUID
Volume UUID: A1F5866F-8286-359A-B19F-58910918AC5A
kserver:~ pbuffer$ diskutil info disk0s3 | grep UUID
Volume UUID: A1F5866F-8286-359A-B19F-58910918AC5A
kserver:~ pbuffer $ diskutil info disk0s4 | grep UUID
Volume UUID: CBB0B1F8-07D5-3BFC-9B50-4F99033B01D6

If you do find a duplicate, you can generate a new UUID and set it using the following command:

unmount the disk first

diskutil unmountDisk disk0

/System/Library/Filesystems/hfs.fs/hfs.util -s disk0s2

substitute your own device for disk0s2

Once you’ve done this, re-bless the volume.

Duplicate UUIDs shouldn’t happen, but somehow it happened to one of our Xserves with a hardware raid card.

No creation dates from stat

I was surprised to learn that creation dates are not included in stat output. I really thought stat would include something so basic. You get time of last access, time of last data modification, and time of last file status change, but creation date isn’t in there.

On the Mac, this info is stored in the resource fork. You can get it from the command line using GetFileInfo which is installed when you install Apple’s free Developer Tools.

/Developer/Tools/GetFileInfo -d path/to/file

In Applescript you can use info for:

creation date of (info for (choose file))

Notes on Leopard AD Plugin 10.5.2

The Active Directory plugin is finally usable in 10.5.2, but some environments require workarounds.

1.) Your domain must resolve to the ip address of a domain controller. This was not a requirement in previous versions, but Apple is apparently making it a requirement as they closed my bug stating that it was a configuration issue with Active Directory since creation of a domain sets up this dns info by default. If your domain does not resolve to an ip, you need to fix it, or as a workaround, edit your /etc/hosts file to point the ip of one of your domain controllers.

for example if you know you have a domain controller at 10.3.1.23 and your fully qualified domain is domain.forest.com, you’d add this line to /etc/hosts

10.3.1.23 domain.forest.com

2.) Allow Authentication from any domain in forest does not work. Uncheck this box in Directory Utility or using the corresponding flag in dsconfigad. If you don’t do this, the join may succeed, but you won’t be able to lookup or authenticate users or even use dscl on Active Directory. When you uncheck this option, just be sure to add the correct domains to your authentication search path in Search Policy of Directory Utiltity.

3.) Allow Administration by Active Directory Groups does not seem to work. In 10.4, this option seems to nest the AD group you want to allow for administration into the local admin group, so the workaround is to do the same in 10.5 manually using dseditgroup.

sudo dseditgroup -o edit -a “DOMAIN\group name” -t group admin

replacing DOMAIN\group name with your domain and group that you want to give admin access.

This group nesting method gives members of your AD group admin access for both Apple’s Authorization APIs and sudo.

These workarounds got me working, logins are painfully slow, but that may be due to the hosts hack.