#!@@PERL@@
#
# Author: Christopher Browne
# Copyright 2004-2009 Afilias Canada

use Getopt::Long;

# Defaults
$CONFIG_FILE      = '@@SYSCONFDIR@@/slon_tools.conf';
$SHOW_USAGE       = 0;
$WATCHDOG_VERBOSE = 1;

# Read command-line options
GetOptions(
    "config=s" => \$CONFIG_FILE,
    "help"     => \$SHOW_USAGE
);

my $USAGE = "Usage: slon_watchdog [--config file] node# sleep_seconds

    --config file  Location of the slon_tools.conf file

    sleep_seconds  Number of seconds for the watchdog process to sleep
                   between checks

";

if ( $SHOW_USAGE or scalar(@ARGV) != 2 ) {
    die $USAGE;
}

require '@@PERLSHAREDIR@@/slon-tools.pm';
require $CONFIG_FILE;

$node  = $ARGV[0];
$sleep = $ARGV[1];

if ( $node =~ /^(?:node)?(\d+)$/ ) {
    $node    = "node$1";
    $nodenum = $1;
}
else {
    die $USAGE;
}

my $logfile     = "$LOGDIR/slon-watchdog.log";
my $logfile_err = "$LOGDIR/slon-$CLUSTER_NAME-$node.err";

log_to_file( $logfile,
"Invoking watchdog for $CLUSTER_NAME node $nodenum , sleep time = $sleep +/- "
      . int( $sleep / 2 )
      . " seconds" );

while (1) {
    $pid = get_pid($node);
    if ( !($pid) ) {
        my ( $dsn, $dbname ) = ( $DSN[$nodenum], $DBNAME[$nodenum] );
        my $message =
          qq{WATCHDOG: No Slon is running for $CLUSTER_NAME node $nodenum!
You ought to check the postmaster and slon for evidence of a crash!
I'm going to restart slon for $node...
};

        # log to error log as original routine
        log_to_file( $logfile_err, $message );

        # log to watchdog log
        log_to_file( $logfile,
            "No Slon running for $CLUSTER_NAME node $nodenum, restarting slon"
        );

        # First, restart the node using slonik
        if ( $CONFIG_FILE ne "" ) {
            system
"(@@TOOLSBIN@@/slonik_restart_node --config=${CONFIG_FILE} $node | @@SLONBINDIR@@/slonik) >> $logfile_err 2>> $logfile_err";
        }
        else {
            system
"(@@TOOLSBIN@@/slonik_restart_node $node | @@SLONBINDIR@@/slonik) >> $logfile_err 2>> $logfile_err";
        }

        # Next, restart the slon process to service the node
        start_slon($nodenum);
        $pid = get_pid($node);
        log_to_file( $logfile_err,
"WATCHDOG: Restarted slon for the $CLUSTER_NAME cluster $node, new PID $pid"
        );
    }
    else {
        if ($WATCHDOG_VERBOSE) {
            log_to_file( $logfile,
"Found slon daemon for $CLUSTER_NAME $node, PID $pid, Sleeping for $sleep +/- "
                  . int( $sleep / 2 )
                  . " seconds" );
        }
    }
    sleep $sleep + ( rand($sleep) - $sleep / 2 );
}

sub log_to_file {
    my ( $logfile, $message ) = @_;
    chomp $message;
    my $date = `date`;
    chomp $date;

    open( SLONLOG, ">>$logfile" );
    print SLONLOG $date, " | ", $message, "\n";
    close SLONLOG;
}