codeautopilot[bot]
commented
2 months ago Potential solution
The plan to solve the bug involves verifying and correcting the parsing and handling of the criticalthreshold option within the check_logfiles.pl script and ensuring that the logic for applying this threshold is correctly implemented in the Nagios::CheckLogfiles module. The issue appears to be that the criticalthreshold is either not being parsed correctly or not being applied correctly, leading to a CRITICAL status being reported even when the number of error lines is below the threshold.
What is causing this bug?
The bug is likely caused by either incorrect parsing of the criticalthreshold option from the configuration file or flawed logic in the Nagios::CheckLogfiles module that handles this threshold. The criticalthreshold option should dictate the number of error lines required to trigger a CRITICAL status, but it seems that this threshold is not being respected, causing premature CRITICAL alerts.
Code
To address this issue, we need to:
- Verify that the
criticalthresholdoption is correctly parsed from the configuration file. - Ensure that the
criticalthresholdis correctly applied in theNagios::CheckLogfilesmodule. - Add debugging statements to trace the flow and application of the
criticalthresholdlogic.
Step 1: Verify Parsing
Ensure that the criticalthreshold option is correctly parsed and passed to the Nagios::CheckLogfiles object in check_logfiles.pl.
# check_logfiles.pl
# Add debugging statement after parsing command-line options
print STDERR "Parsed criticalthreshold: $commandline{criticalthreshold}\n" if exists $commandline{criticalthreshold};
# Ensure criticalthreshold is included in the options passed to Nagios::CheckLogfiles
if (my $cl = Nagios::CheckLogfiles->new({
...
options => join(',', grep { $_ }
...
$commandline{criticalthreshold} ? "criticalthreshold=".$commandline{criticalthreshold} : undef,
...
),
...
})) {
...
}Step 2: Ensure Correct Application
Review and correct the logic within the Nagios::CheckLogfiles module to ensure that the criticalthreshold is correctly applied.
# Nagios/CheckLogfiles.pm
# Add debugging statement to trace the application of criticalthreshold
sub check_thresholds {
my ($self, $count) = @_;
print STDERR "Checking thresholds with count: $count and criticalthreshold: $self->{criticalthreshold}\n";
if ($count >= $self->{criticalthreshold}) {
return 'CRITICAL';
} elsif ($count >= $self->{warningthreshold}) {
return 'WARNING';
} else {
return 'OK';
}
}Step 3: Add Detailed Debugging Statements
Add more detailed debugging statements to trace the internal states and threshold counts more precisely.
# Nagios/CheckLogfiles.pm
# Add debugging statements around threshold checks
sub analyze_logfile {
my ($self, $logfile) = @_;
my $count = 0;
while (my $line = <$logfile>) {
if ($line =~ /$self->{criticalpattern}/) {
$count++;
}
}
print STDERR "Total critical pattern matches: $count\n";
return $self->check_thresholds($count);
}How to replicate the bug
To replicate the bug, follow these steps:
- Create a configuration file with the
criticalthresholdoption set to a specific value (e.g., 10). - Run the
check_logfilesplugin with the configuration file and a log file containing fewer error lines than thecriticalthreshold. - Observe that the plugin reports a CRITICAL status even though the number of error lines is below the threshold.
Example configuration file (logfile_icinga.cfg):
$seekfilesdir = '/var/tmp/check_logfiles';
$protocolsdir = '/var/tmp/check_logfiles';
$scriptpath = '/usr/lib64/nagios/plugins';
@searches = (
{
tag => 'icinga2_client_handshake_errors',
logfile => '/var/log/icinga2/icinga2.log',
criticalpatterns => [
'Client TLS handshake failed'
],
options => 'noprotocol,nosticky,nosavethresholdcount,nosavestate,criticalthreshold=10,warningthreshold=5,maxage=15m',
}
);Command to run the plugin:
'/usr/bin/sudo' '/usr/lib64/nagios/plugins/check_logfiles' '--config' '/etc/nagios/logfile_icinga.cfg' '--tag' 'icinga2_client_handshake_errors'By following these steps, you should be able to observe the bug and verify that the solution correctly addresses the issue.
Click here to create a Pull Request with the proposed solution
Files used for this task:
Napsty
Seen a weird problem today where
check_logfilescorrectly identifies error patterns in a log file. The config file sets multiple options, includingcriticalthreshold=10, yet the plugin reports a CRITICAL status when finding a number of error lines below the threshold.Config file:
Command line usage would be:
'/usr/bin/sudo' '/usr/lib64/nagios/plugins/check_logfiles' '--config' '/etc/nagios/logfile_icinga.cfg' '--tag' 'icinga2_client_handshake_errors'.The Icinga2 alert history shows that the status of this service check switches to critical already after finding just a single error line within the run.
To my understanding this should only be the case if 10 or more error lines were found for this run? Or am I misunderstanding something or potentially breaking things with one of the other options?