#!/usr/bin/perl -w
# parse_bblogs.pl
# Darren - 15th Feb 2006
#
# Simple script to parse and summarise Big Brother logs
# Would generally be invoked via crond
# Will produce a summary of all logs found in $logs_dir
#  and write to $outfile in the following format:
#
#  hostname:test:status:duration
#

use strict;
use Fcntl qw(:DEFAULT :flock);
use Readonly;
use Log::Trivial;

#################################
#
# Adjust the following to suit

# regex to match the filename format of the bb logs
Readonly my $LOGFILE_MATCH => qr/-\d\./;

my $logs_dir = qw( /home/bb/bbvar/logs );
my $outfile = qw( /home/bb/bb/www/bbstatus.current );
my $debug = 0;

#################################
#
# Should be no need to change anything below here

# Create a new logfile each day
chomp(my $today = `date +%Y-%m-%d`);
my $logfile = qq(/var/log/bb/$0-$today);

my $logger = Log::Trivial->new(
        log_file => "$logfile",
        log_mode => "single"
        );

opendir(DIR, $logs_dir)
   or die "Cannot opendir $logs_dir:$!";

my @files = grep { /$LOGFILE_MATCH/ && -f "$logs_dir/$_" } readdir DIR;
closedir DIR;

# Need an exclusive lock on the output file
# (Assuming of course, that everybody else is playing by the rules :)

sysopen(OUT, $outfile, O_WRONLY | O_CREAT)
   or die "Cannot open $outfile for writing:$!\n";
flock(OUT, LOCK_EX)
   or die "Cannot get a lock on $outfile:$!\n";
truncate(OUT, 0)
   or die "Cannot truncate $outfile:$!\n";

FILE:
for my $file (@files) {

    debug("Processing $file") if $debug;

    # Because the logs are automagically created by BB,
    # we can be quite strict about the format we expect to see
    # ie: hostname.test

    my ($host, $test) = split(/\./, $file, 2)
        or $logger->write("WARNING: Skipping unrecognised logfile: $file")
        and next FILE;

    open BBLOG, "<", "$logs_dir/$file"
        or $logger->write("ERROR: I could not open $file: $!")
        and next FILE;

    chomp(my @lines = <BBLOG>);

    # The test status should ALWAYS be the first "word" on the first line
    # And the status duration should ALWAYS be contained on the 2nd last line

    debug($lines[0], $lines[-2]) if $debug;

    my ($status) = ($lines[0] =~ /^([a-z]+)/);
    my ($dur) = ($lines[-2] =~ /Status unchanged in (.*)$/);

    if (!defined $status && !defined $dur) {
        $logger->write("WARNING: Skipping malformed logfile: $file");
        next FILE;
    }

    close BBLOG;

    # If we get to here, all is good and so we write to the output file

    print OUT "$host:$test:$status:$dur\n";
}

close OUT;

sub debug {
    $logger->write("DEBUG: $_") for @_;
}