August 2008 - launchd-dev - lists.macosforge.org

SampleD failure with dynamic SockServiceName
by David Anderson 13 Aug '09

13 Aug '09

My intention is have launchd start a daemon on a dynamic port, publish the port number via bonjour, and then connect to this port after determining the port number using CFNetService (Bonjour). Starting from SampleD (and using the included client.pl), I can advertise the service on a hard-coded port via bonjour, lookup the port number using Bonjour Browser, modify client.pl to use this port, and connect using client.pl. The SampleD binary starts correctly in an OnDemand fashion correctly. If I change <key>SockServiceName</key> <string>12345</string> to <key>SockServiceName</key> <string>0</string> then lookup the dynamic port number using Bonjour Browser and configure client.pl to use this port, client.pl will NOT connect to this port and outputs this error: connect: Connection refused at ./client.pl line 77. With a dynamic port, I am unable to connect to this port using a modified client.pl. I can find no evidence that the SampleD binary is starting in an OnDemand fashion. Adding <key>OnDemand</key> <false/> has no effect. Is there anything different about the default configuration of a dynamic port vs a hard-coded port that would impeded the ability to connect to the dynamically assigned port? Thanks, Dave

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can i do this with launchd? (on-demand auto-restart daemons)
by Ian 29 Aug '08

29 Aug '08

i am interested in writing a cocoa front end to hellanzb. it is a python program that has a daemon mode. you interact with it via a tcp socket. i want to use launchd to control the daemon. 1. it should start when the cocoa GUI is started (either manually or via a startup item) 2. if the daemon dies for whatever reason, launchd should restart it 3. if the GUI is closed, the daemon should be shut off without having it restart. thank you for your help. ian

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No pboard server?
by Dave Dribin 29 Aug '08

29 Aug '08

Hi all, This is sort of a last ditch effort before I re-install.... A few hours ago, copy and paste stopped working on my MBP (running 10.5.4). Sure enough pboard was dead. I decided to reboot, just in case anything else got messed up. Now it will not start at all. Running "launchctl list" does not show it, and if I try and explicitly list it, I get the following error message: % launchctl list com.apple.pboard launch_msg(): Socket is not connected I get the same error message if I try to load com.apple.pboard.plist. I've also noticed that Apache and ssh-agent also are no longer starting, either, so something is definitely wonky with some of the system daemons. There are probably other critical daemons not starting, I imagine, too. Note: there's plenty of free disk space (32 GB). Any other idea? I'm nearly ready to re-install at this point. Thanks, -Dave

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Restrict so only one instance runs
by Crawford Kyle 28 Aug '08

28 Aug '08

Hello, I often need to schedule scripts to run at an interval, but I don't know how long that script will take to complete and I don't want the script to run again at its normal interval unless the script isn't running. I've done this with pid files and grepping through ps lists to exit the script if another instance is running, but I was wondering if there is something built into launchd to handle this. I tried combining LaunchOnlyOnce with StartInterval, but with LaunchOnlyOnce, it seems that the job gets unloaded as soon as it runs, so the interval becomes pretty meaningless. Is there a way to do this with launchd? Should there be a way to do this with launchd? Thanks, Kyle

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Re: [launchd-dev] Stopping and uninstalling a LaunchDaemon job
by Shawn Erickson 27 Aug '08

27 Aug '08

On Wed, Aug 27, 2008 at 8:36 AM, Quinn <eskimo1(a)apple.com> wrote: > At 8:24 -0700 27/8/08, Shawn Erickson wrote: >>Sorry the guy that has been playing around with this isn't in just yet >>so I don't know the exact specifics but... It is my understanding he >>is using authorization services to run a script and that script is >>removing files, etc. just fine but launchctl running from under that >>script cannot see the top level launchctl instance to remove the >>launch daemon job. I believe he used id in the script as it logged the >>current user. > > OK, this sounds like one of the standard gotchas with > AuthorizationExecutionWithPrivileges; it runs the resulting program > with EUID == 0 but RUID inherited from the process that called AEWP > <rdar://problem/4098710>, and launchctl is getting confused by the > RUID. Ah that likely explains what he saw. Thanks > If you were writing real code I would recommend: > > 1. don't use a script, use a C-based tool > > 2. in that tool call setuid(0) to force the RUID to 0 > > However, given that you're just putting in a temporary hack then I'll > recommend the following trick: > > $ chroot -u 0 / launchctl <args> > > which converts an EUID == 0 / RUID != 0 context into a EUID == RUID > == 0. Sneaky huh? Interesting. Thanks again. > IMPORTANT: Please don't leave these hacks in your production code. > In my experience "temporary + work == permanent". Yup they have a way of doing that luckily this component is throw away, at least in this form. -Shawn

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Re: [launchd-dev] Stopping and uninstalling a LaunchDaemon job
by Shawn Erickson 27 Aug '08

27 Aug '08

On Wed, Aug 27, 2008 at 8:15 AM, Quinn <eskimo1(a)apple.com> wrote: > At 8:08 -0700 27/8/08, Shawn Erickson wrote: >>We have no issues using the rights we are granted to remove files >>owned by root, etc. but we cannot use launchctl to stop the >>LaunchDaemon because the uninstall task runs as the current user and >>not as root (aka doesn't see the top level launchd instance). > > I'm confused. To remove a file from /Library/LaunchDaemons you have > to be running as root. Why can't you sublaunch launchctl from that > context? Sorry the guy that has been playing around with this isn't in just yet so I don't know the exact specifics but... It is my understanding he is using authorization services to run a script and that script is removing files, etc. just fine but launchctl running from under that script cannot see the top level launchctl instance to remove the launch daemon job. I believe he used id in the script as it logged the current user. I will pull up the code he is playing with, if I can find it, or wait until he gets in... -Shawn

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Stopping and uninstalling a LaunchDaemon job
by Shawn Erickson 27 Aug '08

27 Aug '08

Looking for opinion on the best way to manage the uninstall of a launchd job that lives under /Library/LaunchDaemon. The uninstall process is currently planned to be triggered by an button/option displayed on one of the tabs of our system preferences plug-in. If the user clicks this we get authorization rights and attempt to do the uninstall that is needed. We have no issues using the rights we are granted to remove files owned by root, etc. but we cannot use launchctl to stop the LaunchDaemon because the uninstall task runs as the current user and not as root (aka doesn't see the top level launchd instance). Note this is a temporary issue in an alpha version of our product since we plan to begin utilizing an IPC mechanism to have our preference plug-in, etc. connect with our launch daemon. When this is up an going we can message the daemon directly to get it to do aspects of the uninstall and shutdown (since it is running as root). In other words this is just a quick uninstall solution for alpha and something that will be replaced... so not looking for something to fancy. -Shawn

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make sure process starts before login window
by Blake Garner 20 Aug '08

20 Aug '08

I'm looking for suggestions or examples on how to make sure a script runs before login window starts. Any ideas on how to make that happen within launchd? Thanks, Blake

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Re: [launchd-dev] LaunchAgent causing bug message in logs?
by Tim Schooley 20 Aug '08

20 Aug '08

Hi Dave, On Wed, 20 Aug 2008 08:11:12 -0700, Dave Zarzycki wrote: > The above contains a typo. SuccessfulExit contains one 'l', not two. > Also, please note that by setting OnDemand to false, that makes > RunAtLoad to true redundant. The same is true of the conditional > KeepAlive (it also is redundant). Please also note that OnDemand was > deprecated in favor of KeepAlive == true (and therefore making launchd > more consistent about the default value of boolean keys). Thanks for the comments - I've updated the plist accordingly. > If you want to file a bug on this, we'd appreciate it. I'll get on the case. Kind regards, Tim

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LaunchAgent causing bug message in logs?
by Tim Schooley 20 Aug '08

20 Aug '08

Hi all, My LaunchAgent appears to cause the following message to be displayed in the log file when it is loaded via launchctl (also note that the agent is for Aqua sessions only): com.apple.launchd[553] (com.company.agent): Bug: launchd_core_logic.c:5025 (23585):22: false Normally, I would pull the source from the site, and grep for stuff to hunt down the cause of this. But I can't find a way of pulling the SVN source :( I did have a look through the source browser, but without knowing which version of the code I'm using, I'm a little bit stuck. Should this message worry me/you? Kind regards, Tim

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