added cpu-overload.pl

Author: Grauwolf

cpu-overload.pl

@@ -0,0 +1,77 @@
+#!/usr/bin/env perl
+
+use strict;
+use warnings;
+use v5.10;
+use Storable qw/store retrieve/;
+
+my $limit     = 0.75;
+my $statefile = '/tmp/icinga-cpu-overload.state';
+
+my %data_diff;
+my $data_old;
+my $data_new = parse_data();
+
+eval { $data_old = retrieve( $statefile ); };
+# on first run there won't be a state file
+if ( $@ ) {
+    store $data_new, $statefile or die "Can't store %data_new to $statefile!\n";
+    exit 1;
+}
+store $data_new, $statefile or die "Can't store %data_new to $statefile!\n";
+
+my $alert;
+for my $cpu ( sort keys %{ $data_new } ) {
+    for my $key ( keys %{ $data_new->{ $cpu } } ) {
+        $data_diff{ $cpu }{ $key } = $data_new->{ $cpu }->{ $key } - $data_old->{ $cpu }->{ $key };
+    }
+
+    my $user     = $data_new->{ $cpu }->{user};
+    my $irq      = $data_new->{ $cpu }->{irq};
+    my $softirq  = $data_new->{ $cpu }->{softirq};
+    my $system   = $data_new->{ $cpu }->{system};
+    my $nice     = $data_new->{ $cpu }->{nice};
+    my $iowait   = $data_new->{ $cpu }->{iowait};
+    my $idle     = $data_new->{ $cpu }->{idle};
+
+    if ( (($system + $irq + $softirq) / ($user + $nice + $iowait + $idle)) > $limit ) {
+        $alert .= " $cpu";
+    }
+}
+
+if ( $alert ) { say "CRITICAL - following cpus are overloaded $alert"; exit 2; }
+else { say 'OK - all CPUs seem to be fine.'; }
+
+################################################################################
+sub parse_data {
+################################################################################
+    my $stat_ref = read_file( '/proc/stat' );
+    my @raw_data = grep( /^cpu\d+/, @{ $stat_ref });
+    my %data_tmp;
+
+    for my $line ( @raw_data ) {
+        chomp $line;
+        my ( $cpu, $user, $nice, $system, $idle, $iowait, $irq, $softirq, $steal ) = split( /\s+/, $line );
+        $data_tmp{$cpu} = {
+            user    => $user,
+            nice    => $nice,
+            system  => $system,
+            idle    => $idle,
+            iowait  => $iowait,
+            irq     => $irq,
+            softirq => $softirq
+        };
+    }
+
+    return \%data_tmp;
+}
+
+################################################################################
+sub read_file {
+################################################################################
+    my $filename = shift;
+    open(my $fh, '<:encoding(UTF-8)', $filename)
+        or die "Could not open file '$filename' $!";
+    my @content = <$fh>;
+    return \@content;
+}