Re: Run Once

[Jerry Christopher]

To expand on that a little, an example from earlier this month where 
Brian explains how he tests whether a system has sysstat, defines a 
class based on this test, and later runs a shellcommand if the class is 
not defined for a system.  You might be able to use the same method.

--
Jerry Christopher
AMCC

Brian Youngstrom wrote:

* Pur A. Lux <puralux@yahoo.com> [030212 10:06]:

> > What techniques have people used to do this
> > within cfengine?
>  

Here is what I currently use:

-----
classes:
       HasSYSSTAT              = ( FileExists(/usr/bin/sar) )
       HasUP2DATE              = ( FileExists(/usr/sbin/up2date) )
[...]
shellcommands:
       redhat.!HasSYSSTAT::
               "/bin/rpm -U http://hagrid/rpms/sysstat-4.0.5-1.i386.rpm";
                       useshell=false
                       timeout=60

       HasUP2DATE::
               '/bin/rpm -e up2date'
                       useshell=false
                       timeout=10
-----

The FileExists checks look for a file that is included in a particuar
package that I care to watch for.  Then I either install or remove the
package depending on which package is present.

I have a script that checks for updates daily, so I don't check for a
version specific file here.  I just have to remember to update the rpm
-i line when I have a new rpm. :)

One could use a module to define classes for each rpm installed, then
have appropriate shellcommands to install/remove as you wish.

-- Brian Youngstrom byoung@cs.washington.edu University of Washington 
Computer Science & Engineering



Jamie Wilkinson wrote:

> This one time, at band camp, Nathan Hubbard wrote:
>  
>
> > So, does anyone know of the easiest way to guarantee a task will run once?  
> > I'm looking to make sure every  machine runs a command one time...it 
> > doesn't matter when, just that it does it once.  Any ideas?  
> >    
>
> You need to set some flag to indicate that the command has been run, and
> test for it.  For example, on my Red Hat boxes, I need to run chkconfig only
> if the service hasn't already been enabled (or disabled, depending) on some
> systems.  So I do some funky stuff in shellcommands to do the test and set
> a class, and then if the class is defined run chkconfig to turn on or off
> the service.
>
>