What emits mounted event?

Grail Dane grail69 at hotmail.com
Thu May 26 00:41:54 UTC 2011


Shows you what a bit of reading can do :)
I added --no-wait and now the below scenario works.  Happy for feedback if this would be anincorrect approach?
cheers grail

From: grail69 at hotmail.com
To: upstart-devel at lists.ubuntu.com
Subject: RE: What emits mounted event?
Date: Thu, 26 May 2011 00:27:17 +0000








Hi James
Yes I did read the cookbook part about instance, but was still a little confused ... will probably wait till I need it :)
I do understand what you have said about adding mounting but not sure I can see an easy wayto implement as I try to keep my scripts fairly generic so as to not have a user required to edit later.This being said I may not know exactly what will be mounted so unable to add mounting priorto it occurring.  I do not however see this as a big issue (yet) as I see nothing that would currently requireto know when this is happening.
An issue I have run into with my approach is as follows:
I have altered the snippet below to look like - 
while read -r MOUNT C_TYPEdo    initctl emit mounted MOUNTPOINT=$MOUNT TYPE=$C_TYPEdone</proc/mounts
(This would also make it easy to add DEVICE and OPTIONS as all are contained here)
The issue that is being caused is that if I ask a script to do the following - 
start on ( mounted MOUNTPOINT=/dev TYPE=/devtmpfs       and mounted MOUNTPOINT=/sys )
This never runs. I am guessing as the emits happen sequentially and the clause is using 'and'that these 2 things are not true at the same time??
Now I noticed from the cookbook and the man page of upstart-events that mountall emits these asa hook, defined as:
Hook - Blocking. Waits for events  that  start on  or stop on this
Is there a way for me to emit mine in a similar fashion?
cheersgrail
PS. Thanks for all the information
> Date: Wed, 25 May 2011 14:24:39 +0100
> From: james.hunt at canonical.com
> To: grail69 at hotmail.com
> CC: upstart-devel at lists.ubuntu.com
> Subject: Re: What emits mounted event?
> 
> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
> 
> Hi Grail,
> 
> On 24/05/11 02:14, Grail Dane wrote:
> > Well that was a quick and easy test :)
> > 
> > I would like to add an additional question, if in my mountall.conf I
> > place a loop to go through all
> > mounted items, as per the output of mount, and issued a similar line to
> > below, would
> > I need to use 'anything' to tie the MOUNTPOINT and TYPE to the specific
> > call?
> > 
> > eg.
> > 
> > while read -r M T
> > do
> >     initctl emit mounted MOUNTPOINT=$M TYPE=$T
> > done< <(mount | awk '{print $3,$5}')
> > 
> > Will this be enough for anything listening or would MOUNTPOINT and TYPE
> > need to last longer and so
> > somehow be individual, maybe using instance? (not a full bottle on how
> > to use that just yet)
> You shouldn't need to use "instance" - /sbin/mountall doesn't. There is
> some info on the instance stanza in the cookbook if you're interested
> though:
> 
> http://upstart.ubuntu.com/cookbook/#instance
> 
> Bear in mind that if you want to provide an environment like that on
> Ubuntu, you should emit both a mounting(7) and a mounted(7) event. See:
> 
> http://manpages.ubuntu.com/manpages/natty/en/man7/mounting.7.html
> http://manpages.ubuntu.com/manpages/natty/en/man7/mounted.7.html
> 
> You might also want to set the DEVICE and OPTIONS variables.
> 
> The loop idea should work since by that stage all the devices will
> already be mounted, but of course that's not what /sbin/mountall does -
> it emits the events *as* the device is mounted. All that should mean for
> you though is that jobs that "start on mounting" / "start on mounted"
> will start slightly later than the possibly could do (but rather that
> than having them start too early :-)
> 
> Regards,
> 
> James.
> 
> > 
> > The idea I am shooting for is to allow others to potentially use 'start
> > on mounted' for anything within the system.
> > 
> > cheers
> > grail
> > 
> > ------------------------------------------------------------------------
> > From: grail69 at hotmail.com
> > To: upstart-devel at lists.ubuntu.com
> > Subject: RE: What emits mounted event?
> > Date: Tue, 24 May 2011 00:46:15 +0000
> > 
> > Hi James
> > 
> > Thank you very much for the suggestion below.  I did actually find
> > something on this in the Cookbook (like I said I think it is a great
> > piece of literature for those of us trying to learn :) )
> > 
> > I will definitely take your advice on raising examples
> > 
> > cheers
> > grail
> > 
> >> Date: Mon, 23 May 2011 20:14:22 +0100
> >> From: james.hunt at ubuntu.com
> >> To: grail69 at hotmail.com
> >> CC: upstart-devel at lists.ubuntu.com
> >> Subject: Re: What emits mounted event?
> >>
> >> Hi Grail,
> >>
> >> On 23/05/11 05:09, Grail Dane wrote:
> >> > Ahhh ... I thought it might have been ... hence my issue :(
> >> >
> >> > In that case, is there an alternative if you are using simple mount
> > command?
> >> Although a vanilla Upstart system won't provide you with the mounted
> >> event, you can of course emit such an event yourself:
> >>
> >> initctl emit mounted MOUNTPOINT=/var/run ...
> >>
> >> >
> >> > cheers
> >> > grail
> >> >
> >> > PS.
> >> > I have been recently reading through the Cookbook that was talked about
> >> > here a little while back.
> >> > Unfortunately it is Ubuntu centric and does not give the standard option
> >> > as well as the Ubuntu
> >> > version :( (maybe others would be interested in starting an upstart
> >> > cookbook)
> >> The cookbook is Ubuntu-centric in a sense, but we have gone to some
> >> pains to point out Ubuntu-specific differences:
> >>
> >> http://upstart.ubuntu.com/cookbook/#ubuntu-specific
> >> http://upstart.ubuntu.com/cookbook/#ubuntu-transient
> >>
> >> The fact that it does tend to cover Ubuntu more fully is because the
> >> authors are working with Upstart on Ubuntu and also the O/S most users
> >> are most likely to come across with Upstart installed is Ubuntu.
> >>
> >> That said, it makes a lot of sense to outline where appropriate the
> >> "generic" methodology so we'll try to bear this in mind for future
> >> updates. If you have concrete examples of where this would be helpful,
> >> please raise bugs on the cookbook itself:
> >>
> >> https://bugs.launchpad.net/upstart-cookbook/+filebug
> >>
> >> > So I have been struggling to find options to create scripts based on
> >> > standard applications (by
> >> > standard i am talking from an (C)LFS point of view and without any other
> >> > SysV reliance)
> >> Again, please raise bugs for specific scenarios.
> >>
> >> Regards,
> >>
> >> James
> >>
> >> >
> >> >> Date: Mon, 23 May 2011 13:40:59 +1000
> >> >> From: apollock at debian.org
> >> >> To: grail69 at hotmail.com
> >> >> CC: upstart-devel at lists.ubuntu.com
> >> >> Subject: Re: What emits mounted event?
> >> >>
> >> >> On Mon, May 23, 2011 at 03:28:57AM +0000, Grail Dane wrote:
> >> >> >
> >> >> > Hi All
> >> >> > I have been looking over some of the Ubuntu upstart scripts to see
> >> > what can help me.
> >> >> > I tried using the mounted-varrun.conf script but for some reason my
> >> > system doesn't seem to pass on thefact that /var/run is mounted. I have
> >> > found though that if after the system has started and I login, I am able
> >> > to enter the following:
> >> >> > start mounted-varrun
> >> >> > This does then successfully follow the script and perform the
> >> > actions as specified
> >> >> > Is anyone able to tell me why this is not captured during the
> >> > startup process?
> >> >> > cheersgrail
> >> >>
> >> >> I can't help with your specific problem, but the mountall program
> >> > (from the
> >> >> mountall package) emits the mounted event (at least in Ubuntu 10.04)
> >> >>
> >> >> regards
> >> >>
> >> >> Andrew
> >> >
> >>
> > 
> > -- upstart-devel mailing list upstart-devel at lists.ubuntu.com Modify
> > settings or unsubscribe at:
> > https://lists.ubuntu.com/mailman/listinfo/upstart-devel
> > 
> 
> 
> - -- 
> Cheers,
> 
> James.
> - --
> James Hunt
> ____________________________________
> Ubuntu Foundations Team, Canonical.
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