Re: matches=0 still triggers action

[Brendan Strejcek]

Okay, after reading this message I decided to try a few processes
statements to look for and warn about processes. I don't want cfagent to
do anything in response to them, just to warn about them, but I can't
get it to behave in the way that I want. For example, I want to know if
more than 6 ssh-agent processes are running (but I don't want any mail
sent if the number is 6 or less). I'm using sleep rather than ssh-agent
for ease of testing. This is what I have:

    processes:
        "sleep" matches=<6 action=warn inform=off

However, this produces output summarizing all the running processes that
match the sleep regex even when there is less than six. When there are
more than six, I get an additional message like:

    a: 8 processes matched sleep (should be <=6)

so I know I have the logic right. So how do I get cfagent to shut up
unless the criteria is met?

I've tried this both with inform on and off. And I've tried with a
define= and an alert (which is much easier to read since it doesn't
stick the ps header in for every process cited but seems to have the
same problem).

Should I be using a filter here? It seems like overkill. Or do I want
action=bymatch ... the ref says: "If the option is set to bymatch, then
signals are only sent to the processes if the matches criteria fail" ...
which sounds like exactly what I want (that is the part about only doing
something if "the matches criteria fail") but I only want to warn, not
send signals.

Ah, that's the trick. So, if action=bymatch, and no signal is specified,
cfagent warns. Though I can't get it to produce the process listing as
with action=warn, all I get is the one line like:

    a: 11 processes matched sleep (should be <=6)

So in the process of writing this I (sort of) solved my own problem,
but it seems like this might be a common thing to want to do and it is
not clear in the ref, so I'm going to go ahead and send it anyways.

Oh, and the define= seems to be triggered if any processes are found,
not respecting the matches= parameter. So using alerts with processes
does not work very well.

Comments?

Sven Mueller wrote:

> David E. Nelson [u] wrote on 02/11/2004 14:57:
> >Hi All,
> >
> >I've the following stanza in my cfengine-2.1.10 cfagent.conf file:
> >
> >solaris.externalnets::
> >
> >         "lpsched$" # External systems do not run print services
> >             matches=0
> >             action=bymatch
> >             restart "/etc/init.d/lp stop"
> >
> >and even though 'lpsched' is not running, cfengine still attempts to stop 
> >printing services.
> 
> That's exactly what you are telling cfengine to do. "restart" is 
> executed whenever the number of processes is either 0 or you sent a 
> sigkill or sigterm to the process(es) via the signal option. Don't use 
> it to stop a process.
> 
> What you are trying to do is probably this:
> 
> solaris.externalnets::
>       "lpsched$"
>       matches=0 # warn if a process was found
>       signal=kill # it shouldn't be running at all,
>                   # so the "hard" kill is OK.
>       action=signal # the default, anyway: Send signal
>                       # action=warn wouldn't send a signal.
>       # if you list the "restart" option here, cfengine would
>         # do the following three things on each run:
>         # 1) warn if at least one process was found running
>       # 2) kill any running process
>       # 3) run whichever command you specify in the "restart"
>       #    option
> 
> Read the doc about the processes section again ;-)
> 
> cu,
> sven
> 
> 
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