Launchd Starting LaunchAgents as a specific user.

Question

Launchd Starting LaunchAgents as a specific user.

Greetings.... I've gotten into the practice of using LaunchD and plists to create launch items, but I am having a unique issue I am hoping we can resolve.

I have a couple of launch items that I need to show up in root's launchd list because I have them run as other users on startup. For example, I have a user called "backups" that uses rsync to pull information form some servers I manage out in the world. Because of how I have set up permissions, I need it to run as that user. However, when I log in, it shows up in MY list of jobs.

This fails because even though I am an administrator, it appears that I do not have the capability (I'm a unix guy, so this makes sense to me) to reset a job as a user.

It is easily remedied after boot by unloading it from my queue, and loading it into root's queue.

The files are located in /Library/LaunchAgents, and are owned by root.

Anyone have a suggestion to fix this?

Mac Pro (2008), Mac OS X (10.5.2)

Posted on Mar 18, 2008 10:14 AM

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Answer 1

Mar 18, 2008 2:08 PM in response to Branden Williams

Maybe they should be in /Users/backups/Library/LaunchAgents, the LaunchAgents directory of the user you want to run them? -LS

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Answer 2

Mar 18, 2008 5:09 PM in response to LordSmoke

It appears this would only work if the "backups" user logged into the machine. It does not physically log in.

Any other suggestions?

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Answer 3

Mar 19, 2008 4:34 AM in response to Branden Williams

Beats me. I'm a Mac noob, and I've only just gotten my local daily, weekly, and monthly backups running via launchd. There I specifically wanted them to run as root.

Maybe create a "backups" acct. with proper UID and GID?

-LS

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Answer 4

Mar 19, 2008 8:06 AM in response to LordSmoke

That exists... and when I run launchctl load XXX as root, it works fine under that user. My problem is when I log in, it loads those two jobs under MY username.

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Answer 5

V.K.

Level 9

56,192 points

Mar 19, 2008 8:28 AM in response to Branden Williams

I don't know what the correct way to do it by hand but I do know that
[Lingon|http://lingon.sourceforge.net> lets you create users daemons that run as root and even run at the login window when no one is logged in. Perhaps you should check it out.

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Answer 6

Mar 19, 2008 8:54 AM in response to V.K.

I actually used Lingon to create the plist files 🙂 But for whatever reason, it is running these under my launchctl queue, not root's.

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Answer 7

Mar 19, 2008 9:03 AM in response to Branden Williams

The apple website at http://developer.apple.com/macosx/launchd.html has a good intro to launchd, and some googling turned up info on specific parameters I needed to modify the cron example to do my bidding (the Weekday and Day keys under StartCalendarInterval). That is pretty much where my research ended.

That said, I understood that the user of whatever was run by launchd was determined by the location of the .plist file - /Library/LaunchDaemons, LaunchAgents = root, /User/username/Library/LaunchDaemon, LaunchAgent = user.

Why do you say launchd or launchctl is loading jobs for "backups" when you log in as "you"? This doesn't make sense on two fronts: the use of the "backups" user and the loading of anything when you log in. I would think only your local .plist jobs would be loaded.

The blind has spoken! -LS

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Answer 8

Mar 19, 2008 9:08 AM in response to Branden Williams

Branden Williams wrote:
I actually used Lingon to create the plist files 🙂 But for whatever reason, it is running these under my launchctl queue, not root's.

IIRC, Lingon (which I tried initially, but the .plist files didn't work due to my use of command-line parameters, so I had to figure out how to roll my own) puts the scripts only in the root or local user directories. Did you do this as "backups" or while logged in as yourself? Maybe check the /Users/you/Library/LaunchDaemons directory? -LS

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Answer 9

Mar 19, 2008 9:14 AM in response to LordSmoke

Ahh, so here's some fun. The scripts are owned by root, and are in /Library/LaunchAgents. But then run as ME when I log in.

Think of the backups user as just a background "service account." So I could have it run under that user specifically, not a problem, but I would never log into the machine under that user, so I need it to run at startup without logging in.

Maybe /Users/backups/Library/LaunchDaemons?

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Answer 10

Mar 19, 2008 9:31 AM in response to Branden Williams

Ahh yep.. there we go.

/Library/LaunchAgents will run for every user that logs in, AS that user.
/Library/LaunchDaemons run on boot.

Working great now!

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Answer 11

Mar 19, 2008 9:32 AM in response to Branden Williams

Branden Williams wrote:

Maybe /Users/backups/Library/LaunchDaemons?

Yes, see my first reply.

I can't recall the difference just now of LaunchAgents vs. LaunchDaemons. The apple link may discuss this.

Also, ownership of the file might matter, but I don't know. All of my run-as-root files are in /Library/LaunchDaemons and are owned by "root" with group "wheel". Maybe yours should be owned by "backups".

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