#!/usr/bin/perl

# Housekeeping program, started by cron, loncontrol and loncron.pl
#
# $Id: loncron,v 1.49 2004/05/11 21:08:55 albertel Exp $
#
# Copyright Michigan State University Board of Trustees
#
# This file is part of the LearningOnline Network with CAPA (LON-CAPA).
#
# LON-CAPA is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# LON-CAPA is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with LON-CAPA; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
#
# /home/httpd/html/adm/gpl.txt
#
# http://www.lon-capa.org/
#

$|=1;
use strict;

use lib '/home/httpd/lib/perl/';
use LONCAPA::Configuration;

use IO::File;
use IO::Socket;
use HTML::Entities;
use Getopt::Long;
#globals
use vars qw (%perlvar %simplestatus $errors $warnings $notices $totalcount);

my $statusdir="/home/httpd/html/lon-status";


# -------------------------------------------------- Non-critical communication
sub reply {
    my ($cmd,$server)=@_;
    my $peerfile="$perlvar{'lonSockDir'}/$server";
    my $client=IO::Socket::UNIX->new(Peer    =>"$peerfile",
                                     Type    => SOCK_STREAM,
                                     Timeout => 10)
       or return "con_lost";
    print $client "$cmd\n";
    my $answer=<$client>;
    chomp($answer);
    if (!$answer) { $answer="con_lost"; }
    return $answer;
}

# --------------------------------------------------------- Output error status

sub log {
    my $fh=shift;
    if ($fh) {	print $fh @_  }
}

sub errout {
   my $fh=shift;
   &log($fh,(<<ENDERROUT));
     <table border="2" bgcolor="#CCCCCC">
     <tr><td>Notices</td><td>$notices</td></tr>
     <tr><td>Warnings</td><td>$warnings</td></tr>
     <tr><td>Errors</td><td>$errors</td></tr>
     </table><p><a href="#top">Top</a></p>
ENDERROUT
}

sub start_daemon {
    my ($fh,$daemon,$pidfile) = @_;
    my $progname=$daemon;
    if ($daemon eq 'lonc' && $ARGV[0] eq 'new') {
	$progname='loncnew'; 
	print "new ";
    }
    system("$perlvar{'lonDaemons'}/$progname 2>>$perlvar{'lonDaemons'}/logs/${daemon}_errors");
    sleep 2;
    if (-e $pidfile) {
	&log($fh,"<p>Seems like it started ...</p>");
	my $lfh=IO::File->new("$pidfile");
	my $daemonpid=<$lfh>;
	chomp($daemonpid);
	sleep 2;
	if (kill 0 => $daemonpid) {
	    return 1;
	} else {
	    return 0;
	}
    }
    &log($fh,"<p>Seems like that did not work!</p>");
    $errors++;
    return 0;
}

sub checkon_daemon {
    my ($fh,$daemon,$maxsize,$sendusr1)=@_;

    &log($fh,'<hr /><a name="'.$daemon.'" /><h2>'.$daemon.'</h2><h3>Log</h3><p style="white-space: pre;"><tt>');
    printf("%-10s ",$daemon);
    if (-e "$perlvar{'lonDaemons'}/logs/$daemon.log"){
	open (DFH,"tail -n25 $perlvar{'lonDaemons'}/logs/$daemon.log|");
	while (my $line=<DFH>) { 
	    &log($fh,"$line");
	    if ($line=~/INFO/) { $notices++; }
	    if ($line=~/WARNING/) { $notices++; }
	    if ($line=~/CRITICAL/) { $warnings++; }
	};
	close (DFH);
    }
    &log($fh,"</tt></p>");
    
    my $pidfile="$perlvar{'lonDaemons'}/logs/$daemon.pid";
    
    my $restartflag=1;
    my $daemonpid;
    if (-e $pidfile) {
	my $lfh=IO::File->new("$pidfile");
	$daemonpid=<$lfh>;
	chomp($daemonpid);
	if (kill 0 => $daemonpid) {
	    &log($fh,"<h3>$daemon at pid $daemonpid responding");
	    if ($sendusr1) { &log($fh,", sending USR1"); }
	    &log($fh,"</h3>");
	    if ($sendusr1) { kill USR1 => $daemonpid; }
	    $restartflag=0;
	    print "running\n";
	} else {
	    $errors++;
	    &log($fh,"<h3>$daemon at pid $daemonpid not responding</h3>");
	    $restartflag=1;
	    &log($fh,"<h3>Decided to clean up stale .pid file and restart $daemon</h3>");
	}
    }
    if ($restartflag==1) {
	$simplestatus{$daemon}='off';
	$errors++;
	&log($fh,'<br><font color="red">Killall '.$daemon.': '.
	    `killall $daemon 2>&1`.' - ');
	sleep 2;
	&log($fh,unlink($pidfile).' - '.
	    `killall -9 $daemon 2>&1`.
	    '</font><br>');
	&log($fh,"<h3>$daemon not running, trying to start</h3>");
	
	if (&start_daemon($fh,$daemon,$pidfile)) {
	    &log($fh,"<h3>$daemon at pid $daemonpid responding</h3>");
	    $simplestatus{$daemon}='restarted';
	    print "started\n";
	} else {
	    $errors++;
	    &log($fh,"<h3>$daemon at pid $daemonpid not responding</h3>");
	    &log($fh,"<p>Give it one more try ...</p>");
	    print " ";
	    if (&start_daemon($fh,$daemon,$pidfile)) {
		&log($fh,"<h3>$daemon at pid $daemonpid responding</h3>");
		$simplestatus{$daemon}='restarted';
		print "started\n";
	    } else {
		print " failed\n";
		$simplestatus{$daemon}='failed';
		$errors++; $errors++;
		&log($fh,"<h3>$daemon at pid $daemonpid not responding</h3>");
		&log($fh,"<p>Unable to start $daemon</p>");
	    }
	}

	if (-e "$perlvar{'lonDaemons'}/logs/$daemon.log"){
	    &log($fh,"<p><pre>");
	    open (DFH,"tail -n100 $perlvar{'lonDaemons'}/logs/$daemon.log|");
	    while (my $line=<DFH>) { 
		&log($fh,"$line");
		if ($line=~/WARNING/) { $notices++; }
		if ($line=~/CRITICAL/) { $notices++; }
	    };
	    close (DFH);
	    &log($fh,"</pre></p>");
	}
    }
    
    my $fname="$perlvar{'lonDaemons'}/logs/$daemon.log";
    
    my ($dev,$ino,$mode,$nlink,
	$uid,$gid,$rdev,$size,
	$atime,$mtime,$ctime,
	$blksize,$blocks)=stat($fname);
    
    if ($size>$maxsize) {
	&log($fh,"<p>Rotating logs ...</p>");
	rename("$fname.2","$fname.3");
	rename("$fname.1","$fname.2");
	rename("$fname","$fname.1");
    }

    &errout($fh);
}

# --------------------------------------------------------------------- Machine
sub log_machine_info {
    my ($fh)=@_;
    &log($fh,'<hr /><a name="machine" /><h2>Machine Information</h2>');
    &log($fh,"<h3>loadavg</h3>");
	
    open (LOADAVGH,"/proc/loadavg");
    my $loadavg=<LOADAVGH>;
    close (LOADAVGH);
    
    &log($fh,"<tt>$loadavg</tt>");
    
    my @parts=split(/\s+/,$loadavg);
    if ($parts[1]>4.0) {
	$errors++;
    } elsif ($parts[1]>2.0) {
	$warnings++;
    } elsif ($parts[1]>1.0) {
	$notices++;
    }

    &log($fh,"<h3>df</h3>");
    &log($fh,"<pre>");

    open (DFH,"df|");
    while (my $line=<DFH>) { 
	&log($fh,&encode_entities($line,'<>&"')); 
	@parts=split(/\s+/,$line);
	my $usage=$parts[4];
	$usage=~s/\W//g;
	if ($usage>90) { 
	    $warnings++;
	    $notices++; 
	} elsif ($usage>80) {
	    $warnings++;
	} elsif ($usage>60) {
	    $notices++;
	}
	if ($usage>95) { $warnings++; $warnings++; $simplestatus{'diskfull'}++; }
    }
    close (DFH);
    &log($fh,"</pre>");


    &log($fh,"<h3>ps</h3>");
    &log($fh,"<pre>");
    my $psproc=0;

    open (PSH,"ps -aux --cols 140 |");
    while (my $line=<PSH>) { 
	&log($fh,&encode_entities($line,'<>&"')); 
	$psproc++;
    }
    close (PSH);
    &log($fh,"</pre>");

    if ($psproc>200) { $notices++; }
    if ($psproc>250) { $notices++; }

    &errout($fh);
}

sub start_logging {
    my ($hostdom,$hostrole,$hostname,$spareid)=@_;
    my $fh=IO::File->new(">$statusdir/newstatus.html");
    my %simplestatus=();
    my $now=time;
    my $date=localtime($now);
    

    &log($fh,(<<ENDHEADERS));
<html>
<head>
<title>LON Status Report $perlvar{'lonHostID'}</title>
</head>
<body bgcolor="#AAAAAA">
<a name="top" />
<h1>LON Status Report $perlvar{'lonHostID'}</h1>
<h2>$date ($now)</h2>
<ol>
<li><a href="#configuration">Configuration</a></li>
<li><a href="#machine">Machine Information</a></li>
<li><a href="#tmp">Temporary Files</a></li>
<li><a href="#tokens">Session Tokens</a></li>
<li><a href="#httpd">httpd</a></li>
<li><a href="#lonsql">lonsql</a></li>
<li><a href="#lond">lond</a></li>
<li><a href="#lonc">lonc</a></li>
<li><a href="#lonhttpd">lonhttpd</a></li>
<li><a href="#lonnet">lonnet</a></li>
<li><a href="#connections">Connections</a></li>
<li><a href="#delayed">Delayed Messages</a></li>
<li><a href="#errcount">Error Count</a></li>
</ol>
<hr />
<a name="configuration" />
<h2>Configuration</h2>
<h3>PerlVars</h3>
<table border="2">
ENDHEADERS

    foreach my $varname (sort(keys(%perlvar))) {
	&log($fh,"<tr><td>$varname</td><td>".
	     &encode_entities($perlvar{$varname},'<>&"')."</td></tr>\n");
    }
    &log($fh,"</table><h3>Hosts</h3><table border='2'>");
    foreach my $id (sort(keys(%{$hostname}))) {
	&log($fh,
	    "<tr><td>$id</td><td>".$hostdom->{$id}.
	    "</td><td>".$hostrole->{$id}.
	    "</td><td>".$hostname->{$id}."</td></tr>\n");
    }
    &log($fh,"</table><h3>Spare Hosts</h3><ol>");
    foreach my $id (sort(keys(%{$spareid}))) {
	&log($fh,"<li>$id\n</li>");
    }
    &log($fh,"</ol>\n");
    return $fh;
}

# --------------------------------------------------------------- clean out tmp
sub clean_tmp {
    my ($fh)=@_;
    &log($fh,'<hr /><a name="tmp" /><h2>Temporary Files</h2>');
    my $cleaned=0;
    my $old=0;
    while (my $fname=<$perlvar{'lonDaemons'}/tmp/*>) {
	my ($dev,$ino,$mode,$nlink,
	    $uid,$gid,$rdev,$size,
	    $atime,$mtime,$ctime,
	    $blksize,$blocks)=stat($fname);
	my $now=time;
	my $since=$now-$mtime;
	if ($since>$perlvar{'lonExpire'}) {
	    my $line='';
	    if (open(PROBE,$fname)) {
		$line=<PROBE>;
		close(PROBE);
	    }
	    unless ($line=~/^CHECKOUTTOKEN\&/) {
		$cleaned++;
		unlink("$fname");
	    } else {
		if ($since>365*$perlvar{'lonExpire'}) {
		    $cleaned++;
		    unlink("$fname");
		} else { $old++; }
	    }
	}
    }
    &log($fh,"Cleaned up ".$cleaned." files (".$old." old checkout tokens).");
}

# ------------------------------------------------------------ clean out lonIDs
sub clean_lonIDs {
    my ($fh)=@_;
    &log($fh,'<hr /><a name="tokens" /><h2>Session Tokens</h2>');
    my $cleaned=0;
    my $active=0;
    while (my $fname=<$perlvar{'lonIDsDir'}/*>) {
	my ($dev,$ino,$mode,$nlink,
	    $uid,$gid,$rdev,$size,
	    $atime,$mtime,$ctime,
	    $blksize,$blocks)=stat($fname);
	my $now=time;
	my $since=$now-$mtime;
	if ($since>$perlvar{'lonExpire'}) {
	    $cleaned++;
	    &log($fh,"Unlinking $fname<br>");
	    unlink("$fname");
	} else {
	    $active++;
	}
    }
    &log($fh,"<p>Cleaned up ".$cleaned." stale session token(s).</p>");
    &log($fh,"<h3>$active open session(s)</h3>");
}


# ----------------------------------------------------------------------- httpd
sub check_httpd_logs {
    my ($fh)=@_;
    &log($fh,'<hr /><a name="httpd" /><h2>httpd</h2><h3>Access Log</h3><pre>');
    
    open (DFH,"tail -n25 /etc/httpd/logs/access_log|");
    while (my $line=<DFH>) { &log($fh,&encode_entities($line,'<>&"')) };
    close (DFH);
	
    &log($fh,"</pre><h3>Error Log</h3><pre>");
	
    open (DFH,"tail -n25 /etc/httpd/logs/error_log|");
    while (my $line=<DFH>) { 
	&log($fh,"$line");
	if ($line=~/\[error\]/) { $notices++; } 
    }
    close (DFH);
    &log($fh,"</pre>");
    &errout($fh);
}

# ---------------------------------------------------------------------- lonnet

sub rotate_lonnet_logs {
    my ($fh)=@_;
    &log($fh,'<hr /><a name="lonnet" /><h2>lonnet</h2><h3>Temp Log</h3><pre>');
    print "checking logs\n";
    if (-e "$perlvar{'lonDaemons'}/logs/lonnet.log"){
	open (DFH,"tail -n50 $perlvar{'lonDaemons'}/logs/lonnet.log|");
	while (my $line=<DFH>) { 
	    &log($fh,&encode_entities($line,'<>&"'));
	}
	close (DFH);
    }
    &log($fh,"</pre><h3>Perm Log</h3><pre>");
    
    if (-e "$perlvar{'lonDaemons'}/logs/lonnet.perm.log") {
	open(DFH,"tail -n10 $perlvar{'lonDaemons'}/logs/lonnet.perm.log|");
	while (my $line=<DFH>) { 
	    &log($fh,&encode_entities($line,'<>&"'));
	}
	close (DFH);
    } else { &log($fh,"No perm log\n") }

    my $fname="$perlvar{'lonDaemons'}/logs/lonnet.log";

    my ($dev,$ino,$mode,$nlink,
	$uid,$gid,$rdev,$size,
	$atime,$mtime,$ctime,
	$blksize,$blocks)=stat($fname);

    if ($size>40000) {
	&log($fh,"<p>Rotating logs ...</p>");
	rename("$fname.2","$fname.3");
	rename("$fname.1","$fname.2");
	rename("$fname","$fname.1");
    }

    &log($fh,"</pre>");
    &errout($fh);
}

# ----------------------------------------------------------------- Connections
sub test_connections {
    my ($fh,$hostname)=@_;
    &log($fh,'<hr /><a name="connections" /><h2>Connections</h2>');
    print "testing connections\n";
    &log($fh,"<table border='2'>");
    my ($good,$bad)=(0,0);
    foreach my $tryserver (sort(keys(%{$hostname}))) {
	print(".");
	my $result;
	my $answer=reply("pong",$tryserver);
	if ($answer eq "$tryserver:$perlvar{'lonHostID'}") {
	    $result="<b>ok</b>";
	    $good++;
	} else {
	    $result=$answer;
	    $warnings++;
	    if ($answer eq 'con_lost') {
		$bad++;
		$warnings++;
	    }
	}
	if ($answer =~ /con_lost/) { print(" $tryserver down\n"); }
	&log($fh,"<tr><td>$tryserver</td><td>$result</td></tr>\n");
    }
    &log($fh,"</table>");
    print "\n$good good, $bad bad connections\n";
    &errout($fh);
}


# ------------------------------------------------------------ Delayed messages
sub check_delayed_msg {
    my ($fh)=@_;
    &log($fh,'<hr /><a name="delayed" /><h2>Delayed Messages</h2>');
    print "checking buffers\n";
    
    &log($fh,'<h3>Scanning Permanent Log</h3>');

    my $unsend=0;

    my $dfh=IO::File->new("$perlvar{'lonDaemons'}/logs/lonnet.perm.log");
    while (my $line=<$dfh>) {
	my ($time,$sdf,$dserv,$dcmd)=split(/:/,$line);
	if ($sdf eq 'F') { 
	    my $local=localtime($time);
	    &log($fh,"<b>Failed: $time, $dserv, $dcmd</b><br>");
	    $warnings++;
	}
	if ($sdf eq 'S') { $unsend--; }
	if ($sdf eq 'D') { $unsend++; }
    }

    &log($fh,"<p>Total unsend messages: <b>$unsend</b></p>\n");
    $warnings=$warnings+5*$unsend;

    if ($unsend) { $simplestatus{'unsend'}=$unsend; }
    &log($fh,"<h3>Outgoing Buffer</h3>\n<pre>");

    open (DFH,"ls -lF $perlvar{'lonSockDir'}/delayed|");
    while (my $line=<DFH>) { 
	&log($fh,&encode_entities($line,'<>&"'));
    }
    &log($fh,"</pre>\n");
    close (DFH);
}

sub finish_logging {
    my ($fh)=@_;
    &log($fh,"<a name='errcount' />\n");
    $totalcount=$notices+4*$warnings+100*$errors;
    &errout($fh);
    &log($fh,"<h1>Total Error Count: $totalcount</h1>");
    my $now=time;
    my $date=localtime($now);
    &log($fh,"<hr />$date ($now)</body></html>\n");
    print "lon-status webpage updated\n";
    $fh->close();

    if ($errors) { $simplestatus{'errors'}=$errors; }
    if ($warnings) { $simplestatus{'warnings'}=$warnings; }
    if ($notices) { $simplestatus{'notices'}=$notices; }
    $simplestatus{'time'}=time;
}

sub log_simplestatus {
    rename ("$statusdir/newstatus.html","$statusdir/index.html");
    
    my $sfh=IO::File->new(">$statusdir/loncron_simple.txt");
    foreach (keys %simplestatus) {
	print $sfh $_.'='.$simplestatus{$_}.'&';
    }
    print $sfh "\n";
    $sfh->close();
}

sub send_mail {
    print "sending mail\n";
    my $emailto="$perlvar{'lonAdmEMail'}";
    if ($totalcount>1000) {
	$emailto.=",$perlvar{'lonSysEMail'}";
    }
    my $subj="LON: $perlvar{'lonHostID'} E:$errors W:$warnings N:$notices"; 
    system("metasend -b -t $emailto -s '$subj' -f $statusdir/index.html -m text/html");
}

sub usage {
    print(<<USAGE);
loncron - housekeeping program that checks up on various parts of Lon-CAPA

Options:
   --help     Display help
   --oldlonc  When starting the lonc daemon use 'lonc' not 'loncnew'
   --noemail  Do not send the status email
   --justcheckconnections  Only check the current status of the lonc/d
                                connections, do not send emails do not
                                check if the daemons are running, do not
                                generate lon-status
   --justcheckdaemons      Only check that all of the Lon-CAPA daemons are
                                running, do not send emails do not
                                check the lonc/d connections, do not
                                generate lon-status
                           
USAGE
}

# ================================================================ Main Program
sub main () {
    my ($oldlonc,$help,$justcheckdaemons,$noemail,$justcheckconnections);
    &GetOptions("help"                 => \$help,
		"oldlonc"              => \$oldlonc,
		"justcheckdaemons"     => \$justcheckdaemons,
		"noemail"              => \$noemail,
		"justcheckconnections" => \$justcheckconnections
		);
    if ($help) { &usage(); return; }
# --------------------------------- Read loncapa_apache.conf and loncapa.conf
    my $perlvarref=LONCAPA::Configuration::read_conf('loncapa.conf');
    %perlvar=%{$perlvarref};
    undef $perlvarref;
    delete $perlvar{'lonReceipt'}; # remove since sensitive and not needed
    delete $perlvar{'lonSqlAccess'}; # remove since sensitive and not needed

# --------------------------------------- Make sure that LON-CAPA is configured
# I only test for one thing here (lonHostID).  This is just a safeguard.
    if ('{[[[[lonHostID]]]]}' eq $perlvar{'lonHostID'}) {
	print("Unconfigured machine.\n");
	my $emailto=$perlvar{'lonSysEMail'};
	my $hostname=`/bin/hostname`;
	chop $hostname;
	$hostname=~s/[^\w\.]//g; # make sure is safe to pass through shell
	my $subj="LON: Unconfigured machine $hostname";
	system("echo 'Unconfigured machine $hostname.' |\
 mailto $emailto -s '$subj' > /dev/null");
	exit 1;
    }

# ----------------------------- Make sure this process is running from user=www
    my $wwwid=getpwnam('www');
    if ($wwwid!=$<) {
	print("User ID mismatch.  This program must be run as user 'www'\n");
	my $emailto="$perlvar{'lonAdmEMail'},$perlvar{'lonSysEMail'}";
	my $subj="LON: $perlvar{'lonHostID'} User ID mismatch";
	system("echo 'User ID mismatch.  loncron must be run as user www.' |\
 mailto $emailto -s '$subj' > /dev/null");
	exit 1;
    }

# ------------------------------------------------------------- Read hosts file
    my $config=IO::File->new("$perlvar{'lonTabDir'}/hosts.tab");
    
    my (%hostname,%hostdom,%hostrole,%spareid);
    while (my $configline=<$config>) {
	next if ($configline =~ /^(\#|\s*\$)/);
	my ($id,$domain,$role,$name,$ip,$domdescr)=split(/:/,$configline);
	if ($id && $domain && $role && $name && $ip) {
	    $hostname{$id}=$name;
	    $hostdom{$id}=$domain;
	    $hostrole{$id}=$role;
	}
    }
    undef $config;

# ------------------------------------------------------ Read spare server file
    $config=IO::File->new("$perlvar{'lonTabDir'}/spare.tab");
    
    while (my $configline=<$config>) {
	chomp($configline);
	if (($configline) && ($configline ne $perlvar{'lonHostID'})) {
	    $spareid{$configline}=1;
	}
    }
    undef $config;

# ---------------------------------------------------------------- Start report

    $errors=0;
    $warnings=0;
    $notices=0;

	
    my $fh;
    if (!$justcheckdaemons && !$justcheckconnections) {
	$fh=&start_logging(\%hostdom,\%hostrole,\%hostname,\%spareid);

	&log_machine_info($fh);
	&clean_tmp($fh);
	&clean_lonIDs($fh);
	&check_httpd_logs($fh);
	&rotate_lonnet_logs($fh);
    }
    if (!$justcheckconnections) {
	&checkon_daemon($fh,'lonsql',200000);
	&checkon_daemon($fh,'lond',40000,1);
	&checkon_daemon($fh,'lonc',40000,1);
	&checkon_daemon($fh,'lonhttpd',40000);
    }
    if (!$justcheckdaemons) {
	&test_connections($fh,\%hostname);
    }
    if (!$justcheckdaemons && !$justcheckconnections) {
	&check_delayed_msg($fh);
	&finish_logging($fh);
	&log_simplestatus();
	
	if ($totalcount>200 && !$noemail) { &send_mail(); }
    }
}

&main();
1;