Subversion Repositories sysadmin_scripts

#! /usr/bin/env perl

use strict;

use warnings;

# Currently three types of tests

# type: lwp

# url: site to test

# timeout: optional integer, number of seconds. defaults to 'default timeout'

#

# type: ping

# url: site to test

# timeout: optional integer, number of seconds. defaults to 'default timeout'

#

# type: netcat

# url: site to test

# port: port to test on

# timeout: optional integer, number of seconds. defaults to 'default timeout'

use Data::Dumper;

use FindBin;

use File::Spec;

# name of script directory, no trailing slash

my $MY_DIR = $FindBin::Bin;

# name of currently executing file

my $MY_NAME = $FindBin::Script;

my $configName = $MY_DIR . '/' . $MY_NAME . '.yaml';

# hashref which holds configuration

my $config;

# simply read the contents of YAML file $filename into

# hashref and return the hashref

sub loadConf {

   use YAML::Tiny;

   my $filename = shift;

   my $conf = YAML::Tiny->read( $filename );

   return $conf->[0];

}

# not used. May use it later, who knows.

sub saveConf {

   use YAML::Tiny;

   my ( $filename, $config ) = @_;

   my $yaml = YAML::Tiny->new( $config );

   $yaml->write( $filename );

}

# check using netcat

sub checkNetCat {

   my ($url, $port, $timeout ) = @_;

   my $netcat = `which nc`;

   chomp $netcat;

   unless ( $netcat ) {

      warn "Netcat not found, not testing\n";

      return 0;

   }

   $netcat = join( ' ', ($netcat, "-z -w $timeout", $url, $port ) );

   `$netcat`;

   return not $? >> 8;

} 

# this has only been tested on http and https, but with a little work

# could do echo, ftp

# will NOT work with some WordPress sites since it goes into

# infinite redirect loop

sub checkHTTP {

   use LWP::UserAgent; # probably should eval this in case not loaded

   my ($url, $timeout) = @_;

   # just getting HEAD, so small amount of data

   my $r = HTTP::Request->new( 'HEAD', $url );

   # new agent, make the request, return success

   my $ua = LWP::UserAgent->new();

   my $res = $ua->request($r);

   return $res->is_success;

}

# we're only using icmp. Probably could extend to other things, but

# netcat and lwp do them also, I think.

# basically a ping. Must be run as root.

sub checkPing {

   my ($url,$type,$timeout) = @_;

   use Net::Ping;

   # verify running as root

   my $login = (getpwuid $>);

   if ( $login ne 'root' ) {

      warn "This script must be run as root for ping type\n";

      return 0;

   }

   my $p = Net::Ping->new('icmp');

   return $p->ping( $url ) ? 1 : 0;

}   

# determines which test to run, runs it and returns results

sub runTest {

   my $parameters = shift;

   #die Dumper( $parameters );

   my $result;

   if ( $parameters->{'type'} eq 'lwp' ) {

      $result = &checkHTTP( $parameters->{'url'}, $parameters->{'timeout'} );

   } elsif ( $parameters->{'type'} eq 'ping' ) {

      $result = checkPing( $parameters->{'url'}, $parameters->{'timeout'} );

   } elsif ( $parameters->{'type'} eq 'netcat' ) {

      $result = checkNetCat( $parameters->{'url'}, $parameters->{'port'}, $parameters->{'timeout'} );

   } else {

      warn "Unknown test type $parameters->{type}, aborting test\n";

      $result = 0;

   }

   return $result;

}

# just make up the flag file name in one place so we don't

# forget to do it everyplace it is needed

sub flagFileName {

   my $name = shift;

   return "/tmp/$name.down";

}

# Report outage via system mail

# your system must be able to send e-mail from 'report from'

# otherwise, you'll need to use something like sendemail.pl

# apt install libemail-sender-perl libemail-mime-perl

sub reportViaMail {

   my ( $name,$parameters ) = @_;

   use Email::MIME;

   my $message = Email::MIME->create(

     header_str => [

       From    => $parameters->{'report from'},

       To      => $parameters->{'report to'},

       Subject => "Outage on $name",

     ],

     attributes => {

       encoding => 'quoted-printable',

       charset  => 'ISO-8859-1',

     },

     body_str => "$name has been reported as current state down\n",

   );

   # send the message

   use Email::Sender::Simple qw(sendmail);

   sendmail($message);   

}   

# report the outage

sub reportOutage {

   my ( $name,$parameters ) = @_;

   if ( $parameters->{'report type'} eq 'mail' ) {

      &reportViaMail( $name,$parameters );

   } else {

      warn "Do not have a way of notifying outage for $name\n";

   }

}

# this will put a flag file in /tmp/monitorNetwork which will control

# countdown in case of failure

# if the countdown is exceeded, it will report the status 

sub processFailure {

   my ( $name, $parameters ) = @_;

   # temporary for testing

   print "Failed test for $name\n";

   my $flagFileName = &flagFileName( $name );

   my $remainingCounts = $parameters->{'failure count'};

   if ( -f $flagFileName ) {

      # open flag file, read the value into $remaingCounts

      return if $remainingCounts == -1;

   }

   if ( $remainingCounts-- == 0 ) {

      &reportOutage( $name, $parameters );

   }

   # open flag file, write new $remainingCounts to it

}

# we are up, so check for any flag file and unlink if found

sub cleanUp {

   my $name = shift;

   $name = &flagFileName( $name );

   unlink $name if -f $name;

}

#######################################################################

#                     Main Code

#######################################################################

# get the config file

$config = &loadConf( $configName );

# loop through each site to check

foreach my $testToRun( keys %{$config->{'sites to check'}} ) {

   # there is a faster way of doing this, but I don't remember it

   # you can merge two hashes, overwriting one with values if not existing in the other

   # I'll look it up, but for now

   foreach my $key ( keys %{$config->{'defaults'}} ) {

      $config->{'sites to check'}->{$testToRun}->{$key} = $config->{'defaults'}->{$key} unless defined $config->{'sites to check'}->{$testToRun}->{$key};

   }

   # run the test

   if ( &runTest( $config->{'sites to check'}->{$testToRun} ) ) {

      &cleanUp( $testToRun ); # success, clean up any old stuff

   } else { # failure, this is what we're here for

      &processFailure( $testToRun, $config->{'sites to check'}->{$testToRun} );

   }

}