On Sep 5, 2007, at 6:48 PM, markd@macports.org wrote:
James Berry <jberry@macports.org> writes:
For those cases where startupitem.executable cannot be used, daemondo also supports the startupitem.pidfile commands that allow the process' pidfile to be monitored: daemondo will read the pidfile and watch for the death of that process.
So daemondo, and thus launchd, will be aware of the daemon process death (and be able to restart the daemon process) only under two circumstances:
(1) startupitem.executable was supplied (thus daemondo starts the process) (2) startupitem.pidfile was supplied (thus daemondo reads the process id)
Under all other circumstances, daemondo will not know that the daemon process has died, and will not exit when the process does die, and thus launchd won't restart the process since it doesn't know it died. Put another way, if daemondo can know the process has died, then launchd will know too, but not otherwise.
These statements seem incompatible with ....
The pidfile keyword is likely used only if executable is not.
This one.
I don't see the incompatibility of those statements, but then I again I know what i meant, not necessarily what it means to others ;). The later sentence, btw, is missing a word on the end. It should read: "the pidfile keyword is likely useful only if the executable keyword is not specified." Does that help any?
Looks to me like startupitem.pidfile must be set for a deamon to be tracked whether it is executable startupitem or not.
No, daemondo will track an "executable" in an case (and it doesn't need to know where their pidfile is, generally, since it launches the code and thus knows the pid). In the case of script code (non "executable") daemondo doesn't know the pid, since it doesn't know what the script code did. In this case, it has to rely on reading a pidfile to get the process id, or else simply not know.
And the man page says startupitem.pidfile is "particularly useful" for startupitem.executable. Can you explain this?
That was either garbage to begin with, or else got messed up in creation of the man page. Off the top of my head I can't see any particular reason to use a pidfile keyword in conjunction with the executable keyword, unless it's to specify that it should delete a pidfile created by the executable, and I'm not sure that even works for that case. Hope that helps. James