#!/usr/bin/perl

# Housekeeping program, started by cron, loncontrol and loncron.pl
#
# $Id: loncron,v 1.99 2013/05/29 18:10:54 raeburn 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 LONCAPA::Checksumming;
use LONCAPA;
use Apache::lonnet;
use Apache::loncommon;

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";


# --------------------------------------------------------- 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 rotate_logfile {
    my ($file,$fh,$description) = @_;
    my $size=(stat($file))[7];
    if ($size>40000) {
	&log($fh,"<p>Rotating $description ...</p>");
	rename("$file.2","$file.3");
	rename("$file.1","$file.2");
	rename("$file","$file.1");
    } 
}

sub start_daemon {
    my ($fh,$daemon,$pidfile,$args) = @_;
    my $progname=$daemon;
    if ($daemon eq 'lonc') {
	$progname='loncnew'; 
    }
    my $error_fname="$perlvar{'lonDaemons'}/logs/${daemon}_errors";
    &rotate_logfile($error_fname,$fh,'error logs');
    if ($daemon eq 'lonc') {
	&clean_sockets($fh);
    }
    system("$perlvar{'lonDaemons'}/$progname 2>$perlvar{'lonDaemons'}/logs/${daemon}_errors");
    sleep 1;
    if (-e $pidfile) {
	&log($fh,"<p>Seems like it started ...</p>");
	my $lfh=IO::File->new("$pidfile");
	my $daemonpid=<$lfh>;
	chomp($daemonpid);
	if ($daemonpid =~ /^\d+$/ && 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,$maxsize,$send,$args)=@_;

    my $result;
    &log($fh,'<hr /><a name="'.$daemon.'" /><h2>'.$daemon.'</h2><h3>Log</h3><p style="white-space: pre;"><tt>');
    printf("%-15s ",$daemon);
    if (-e "$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($daemonpid);
	if ($daemonpid =~ /^\d+$/ && kill 0 => $daemonpid) {
	    &log($fh,"<h3>$daemon at pid $daemonpid responding");
	    if ($send) { &log($fh,", sending $send"); }
	    &log($fh,"</h3>");
	    if ($send eq 'USR1') { kill USR1 => $daemonpid; }
	    if ($send eq 'USR2') { kill USR2 => $daemonpid; }
	    $restartflag=0;
	    if ($send eq 'USR2') {
		$result = 'reloaded';
		print "reloaded\n";
	    } else {
		$result = 'running';
		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++;
	my $kadaemon=$daemon;
	if ($kadaemon eq 'lonmemcached') { $kadaemon='memcached'; }
	&log($fh,'<br><font color="red">Killall '.$daemon.': '.
	    `killall $kadaemon 2>&1`.' - ');
	sleep 1;
	&log($fh,unlink($pidfile).' - '.
	    `killall -9 $kadaemon 2>&1`.
	    '</font><br>');
	&log($fh,"<h3>$daemon not running, trying to start</h3>");
	
	if (&start_daemon($fh,$daemon,$pidfile,$args)) {
	    &log($fh,"<h3>$daemon at pid $daemonpid responding</h3>");
	    $simplestatus{$daemon}='restarted';
	    $result = 'started';
	    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,$pidfile,$args)) {
		&log($fh,"<h3>$daemon at pid $daemonpid responding</h3>");
		$simplestatus{$daemon}='restarted';
		$result = 'started';
		print "started\n";
	    } else {
		$result = 'failed';
		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/$daemon.log";
    &rotate_logfile($fname,$fh,'logs');

    &errout($fh);
    return $result;
}

# --------------------------------------------------------------------- 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++; }

    &log($fh,"<h3>distprobe</h3>");
    &log($fh,"<pre>");
    &log($fh,&encode_entities(&LONCAPA::distro(),'<>&"'));
    &log($fh,"</pre>");

    &errout($fh);
}

sub start_logging {
    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="#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'>");
    my %hostname = &Apache::lonnet::all_hostnames();
    foreach my $id (sort(keys(%hostname))) {
	my $role = (&Apache::lonnet::is_library($id) ? 'library'
		                                     : 'access');
	&log($fh,
	    "<tr><td>$id</td><td>".&Apache::lonnet::host_domain($id).
	    "</td><td>".$role.
	    "</td><td>".&Apache::lonnet::hostname($id)."</td></tr>\n");
    }
    &log($fh,"</table><h3>Spare Hosts</h3><ul>");
    foreach my $type (sort(keys(%Apache::lonnet::spareid))) {
	&log($fh,"<li>$type\n<ol>");
	foreach my $id (@{ $Apache::lonnet::spareid{$type} }) {
	    &log($fh,"<li>$id</li>\n");
	}
	&log($fh,"</ol>\n</li>\n");
    }
    &log($fh,"</ul>\n");
    return $fh;
}

# --------------------------------------------------------------- clean out tmp
sub clean_tmp {
    my ($fh)=@_;
    &log($fh,'<hr /><a name="tmp" /><h2>Temporary Files</h2>');
    my ($cleaned,$old,$removed) = (0,0,0);
    my %errors = (
                     dir       => [],
                     file      => [],
                     failopen  => [],
                 );
    my %error_titles = (
                         dir       => 'failed to remove empty directory:',
                         file      => 'failed to unlike stale file',
                         failopen  => 'failed to open file or directory'
                       );
    ($cleaned,$old,$removed) = &recursive_clean_tmp('',$cleaned,$old,$removed,\%errors);
    &log($fh,"Cleaned up: ".$cleaned." files; removed: $removed empty directories; (found: $old old checkout tokens)");
    foreach my $key (sort(keys(%errors))) {
        if (ref($errors{$key}) eq 'ARRAY') {
            if (@{$errors{$key}} > 0) {
                &log($fh,"Error during cleanup ($error_titles{$key}):<ul><li>".
                     join('</li><li><tt>',@{$errors{$key}}).'</tt></li></ul><br />');
            }
        }
    }
}

sub recursive_clean_tmp {
    my ($subdir,$cleaned,$old,$removed,$errors) = @_;
    my $base = "$perlvar{'lonDaemons'}/tmp";
    my $path = $base;
    next if ($subdir =~ m{\.\./});
    next unless (ref($errors) eq 'HASH');
    unless ($subdir eq '') {
        $path .= '/'.$subdir;
    }
    if (opendir(my $dh,"$path")) {
        while (my $file = readdir($dh)) {
            next if ($file =~ /^\.\.?$/);
            my $fname = "$path/$file";
            if (-d $fname) {
                my $innerdir;
                if ($subdir eq '') {
                    $innerdir = $file;
                } else {
                    $innerdir = $subdir.'/'.$file;
                }
                ($cleaned,$old,$removed) = 
                     &recursive_clean_tmp($innerdir,$cleaned,$old,$removed,$errors);
                my @doms = &Apache::lonnet::current_machine_domains();
                
                if (open(my $dirhandle,$fname)) {
                    unless (($innerdir eq 'helprequests') ||
                            (($innerdir =~ /^addcourse/) && ($innerdir !~ m{/\d+$}))) {
                        my @contents = grep {!/^\.\.?$/} readdir($dirhandle);
                                      join('&&',@contents)."\n";    
                        if (scalar(grep {!/^\.\.?$/} readdir($dirhandle)) == 0) {
                            closedir($dirhandle);
                            if ($fname =~ m{^\Q$perlvar{'lonDaemons'}\E/tmp/}) {
                                if (rmdir($fname)) {
                                    $removed ++;
                                } elsif (ref($errors->{dir}) eq 'ARRAY') {
                                    push(@{$errors->{dir}},$fname);
                                }
                            }
                        }
                    } else {
                        closedir($dirhandle);
                    }
                }
            } else {
                my ($dev,$ino,$mode,$nlink,
                    $uid,$gid,$rdev,$size,
                    $atime,$mtime,$ctime,
                    $blksize,$blocks)=stat($fname);
                my $now=time;
                my $since=$now-$mtime;
                if ($since>$perlvar{'lonExpire'}) {
                    if ($subdir eq '') {
                        my $line='';
                        if ($fname =~ /\.db$/) {
                            if (unlink($fname)) {
                                $cleaned++;
                            } elsif (ref($errors->{file}) eq 'ARRAY') {
                                push(@{$errors->{file}},$fname);
                            }
                        } elsif (open(PROBE,$fname)) {
                            my $line='';
                            $line=<PROBE>;
                            close(PROBE);
                            if ($line=~/^CHECKOUTTOKEN\&/) {
                                if ($since>365*$perlvar{'lonExpire'}) {
                                    if (unlink($fname)) {
                                        $cleaned++; 
                                    } elsif (ref($errors->{file}) eq 'ARRAY') {
                                        push(@{$errors->{file}},$fname);
                                    }
                                } else {
                                    $old++;
                                }
                            } else {
                                if (unlink($fname)) {
                                    $cleaned++;
                                } elsif (ref($errors->{file}) eq 'ARRAY') {
                                    push(@{$errors->{file}},$fname);
                                }
                            }
                        } elsif (ref($errors->{failopen}) eq 'ARRAY') {
                            push(@{$errors->{failopen}},$fname); 
                        }
                    } else {
                        if (unlink($fname)) {
                            $cleaned++;
                        } elsif (ref($errors->{file}) eq 'ARRAY') {
                            push(@{$errors->{file}},$fname);
                        }
                    }
                }
            }
        }
        closedir($dh);
    } elsif (ref($errors->{failopen}) eq 'ARRAY') {
        push(@{$errors->{failopen}},$path);
    }
    return ($cleaned,$old,$removed);
}

# ------------------------------------------------------------ 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>");
}

# ----------------------------------------------------------- clean out sockets
sub clean_sockets {
    my ($fh)=@_;
    my $cleaned=0;
    opendir(SOCKETS,$perlvar{'lonSockDir'});
    while (my $fname=readdir(SOCKETS)) {
	next if (-d $fname 
		 || $fname=~/(mysqlsock|maximasock|rsock|\Q$perlvar{'lonSockDir'}\E)/);
	$cleaned++;
	&log($fh,"Unlinking $fname<br />");
	unlink("/home/httpd/sockets/$fname");
    }
    &log($fh,"<p>Cleaned up ".$cleaned." stale sockets.</p>");
}


# ----------------------------------------------------------------------- httpd
sub check_httpd_logs {
    my ($fh)=@_;
    if (open(PIPE,"./lchttpdlogs|")) {
        while (my $line=<PIPE>) {
            &log($fh,$line);
            if ($line=~/\[error\]/) { $notices++; }
        }
        close(PIPE);
    }
    &errout($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";
    &rotate_logfile($fname,$fh,'lonnet log');

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

sub rotate_other_logs {
    my ($fh) = @_;
    my %logs = (
                  autoenroll          => 'Auto Enroll log',
                  autocreate          => 'Create Course log',
                  searchcat           => 'Search Cataloguing log',
                  autoupdate          => 'Auto Update log',
                  refreshcourseids_db => 'Refresh CourseIDs db log',
               );
    foreach my $item (keys(%logs)) {
        my $fname=$perlvar{'lonDaemons'}.'/logs/'.$item.'.log';
        &rotate_logfile($fname,$fh,$logs{$item});
    }
}

# ----------------------------------------------------------------- Connections
sub test_connections {
    my ($fh)=@_;
    &log($fh,'<hr /><a name="connections" /><h2>Connections</h2>');
    print "testing connections\n";
    &log($fh,"<table border='2'>");
    my ($good,$bad)=(0,0);
    my %hostname = &Apache::lonnet::all_hostnames();
    foreach my $tryserver (sort(keys(%hostname))) {
	print(".");
	my $result;
	my $answer=&Apache::lonnet::reply("ping",$tryserver);
	if ($answer eq "$tryserver:$perlvar{'lonHostID'}") {
	    $result="<b>ok</b>";
	    $good++;
	} else {
	    $result=$answer;
	    $warnings++;
	    if ($answer eq 'con_lost') {
		$bad++;
		$warnings++;
	    } else {
		$good++; #self connection
	    }
	}
	if ($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");
    if ($unsend > 0) {
        $warnings=$warnings+5*$unsend;
    }

    if ($unsend) { $simplestatus{'unsend'}=$unsend; }
    &log($fh,"<h3>Outgoing Buffer</h3>\n<pre>");
# list directory with delayed messages and remember offline servers
    my %servers=();
    open (DFH,"ls -lF $perlvar{'lonSockDir'}/delayed|");
    while (my $line=<DFH>) {
        my ($server)=($line=~/\.(\w+)$/);
        if ($server) { $servers{$server}=1; }
	&log($fh,&encode_entities($line,'<>&"'));
    }
    &log($fh,"</pre>\n");
    close (DFH);
    my %hostname = &Apache::lonnet::all_hostnames();
    my $numhosts = scalar(keys(%hostname));
# pong to all servers that have delayed messages
# this will trigger a reverse connection, which should flush the buffers
    foreach my $tryserver (sort(keys(%servers))) {
        if ($hostname{$tryserver} || !$numhosts) {
            my $answer;
            eval {
                local $SIG{ ALRM } = sub { die "TIMEOUT" };
                alarm(20);
                $answer = &Apache::lonnet::reply("pong",$tryserver);
                alarm(0);
            };
            if ($@ && $@ =~ m/TIMEOUT/) {
                &log($fh,"Attempted pong to $tryserver timed out<br />");
                print "time out while contacting: $tryserver for pong\n";
            } else {
                &log($fh,"Pong to $tryserver: $answer<br />");
            }
        } else {
            &log($fh,"$tryserver has delayed messages, but is not part of the cluster -- skipping 'Pong'.<br />");
        }
    }
}

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 write_loncaparevs {
    print "Retrieving LON-CAPA version information\n";
    my %hostname = &Apache::lonnet::all_hostnames();
    my $output;
    foreach my $id (sort(keys(%hostname))) {
        if ($id ne '') {
            my $loncaparev;
            eval {
                local $SIG{ ALRM } = sub { die "TIMEOUT" };
                alarm(10);
                $loncaparev =
                    &Apache::lonnet::get_server_loncaparev('',$id,1,'loncron');
                alarm(0);
            };
            if ($@ && $@ =~ m/TIMEOUT/) {
                print "time out while contacting lonHost: $id for version\n";   
            }
            if ($loncaparev =~ /^[\w.\-]+$/) {
                $output .= $id.':'.$loncaparev."\n";
            }
        }
    }
    if ($output) {
        if (open(my $fh,">$perlvar{'lonTabDir'}/loncaparevs.tab")) {
            print $fh $output;
            close($fh);
            &Apache::lonnet::load_loncaparevs();
        }
    }
    return;
}

sub write_serverhomeIDs {
    print "Retrieving LON-CAPA lonHostID information\n";
    my %name_to_host = &Apache::lonnet::all_names();
    my $output;
    foreach my $name (sort(keys(%name_to_host))) {
        if ($name ne '') {
            if (ref($name_to_host{$name}) eq 'ARRAY') {
                my $serverhomeID;
                eval {
                    local $SIG{ ALRM } = sub { die "TIMEOUT" };
                    alarm(10);
                    $serverhomeID = 
                        &Apache::lonnet::get_server_homeID($name,1,'loncron');
                    alarm(0);
                };
                if ($@ && $@ =~ m/TIMEOUT/) {
                    print "Time out while contacting server: $name\n"; 
                }
                if ($serverhomeID ne '') {
                    $output .= $name.':'.$serverhomeID."\n";
                } else {
                    $output .= $name.':'.$name_to_host{$name}->[0]."\n";
                }
            }
        }
    }
    if ($output) {
        if (open(my $fh,">$perlvar{'lonTabDir'}/serverhomeIDs.tab")) {
            print $fh $output;
            close($fh);
            &Apache::lonnet::load_serverhomeIDs();
        }
    }
    return;
}

sub write_checksums {
    my $distro = &LONCAPA::distro();
    if ($distro) {
        print "Retrieving file version and checksumming.\n";
        my $numchksums = 0;
        my ($chksumsref,$versionsref) =
            &LONCAPA::Checksumming::get_checksums($distro,$perlvar{'lonDaemons'},
                                                  $perlvar{'lonLib'},
                                                  $perlvar{'lonIncludes'},
                                                  $perlvar{'lonTabDir'});
        if (ref($chksumsref) eq 'HASH') {
            $numchksums = scalar(keys(%{$chksumsref}));
        }
        print "File version retrieved and checksumming completed for $numchksums files.\n";
    } else {
        print "File version retrieval and checksumming skipped - could not determine Linux distro.\n"; 
    }
    return;
}

sub send_mail {
    print "sending mail\n";
    my $defdom = $perlvar{'lonDefDomain'};
    my $origmail = $perlvar{'lonAdmEMail'};
    my $emailto = &Apache::loncommon::build_recipient_list(undef,
                                   'lonstatusmail',$defdom,$origmail);
    if ($totalcount>2500) {
	$emailto.=",$perlvar{'lonSysEMail'}";
    }
    my $subj="LON: $perlvar{'lonHostID'} E:$errors W:$warnings N:$notices"; 

    my $result=system("metasend -b -S 4000000 -t $emailto -s '$subj' -f $statusdir/index.html -m text/html >& /dev/null");
    if ($result != 0) {
	$result=system("mail -s '$subj' $emailto < $statusdir/index.html");
    }
}

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

Options:
   --help     Display 
   --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
   --justreload            Only tell the daemons to reload the config files,
				do not send emails do not
                                check if the daemons are running, do not
                                generate lon-status
                           
USAGE
}

# ================================================================ Main Program
sub main () {
    my ($help,$justcheckdaemons,$noemail,$justcheckconnections,
	$justreload);
    &GetOptions("help"                 => \$help,
		"justcheckdaemons"     => \$justcheckdaemons,
		"noemail"              => \$noemail,
		"justcheckconnections" => \$justcheckconnections,
		"justreload"           => \$justreload
		);
    if ($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 $perlvar{'lonSqlAccess'}; # remove since sensitive and not needed
    chdir($perlvar{'lonDaemons'});
# --------------------------------------- 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;
    }

# -------------------------------------------- Force reload of host information
    &Apache::lonnet::load_hosts_tab(1);
    &Apache::lonnet::load_domain_tab(1);
    &Apache::lonnet::get_iphost(1);

# ----------------------------------------- Force firewall update for lond port  

    if ((!$justcheckdaemons) && (!$justreload)) {
        my $now = time;
        my $tmpfile = $perlvar{'lonDaemons'}.'/tmp/lciptables_iphost_'.
                      $now.$$.int(rand(10000));
        if (open(my $fh,">$tmpfile")) {
            my %iphosts = &Apache::lonnet::get_iphost();
            foreach my $key (keys(%iphosts)) {
                print $fh "$key\n";
            }
            close($fh);
            if (&LONCAPA::try_to_lock('/tmp/lock_lciptables')) {
                my $execpath = $perlvar{'lonDaemons'}.'/lciptables';
                system("$execpath $tmpfile");
                unlink('/tmp/lock_lciptables');  # Remove the lock file. 
            }
            unlink($tmpfile);
        }
    }

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

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

	
    my $fh;
    if (!$justcheckdaemons && !$justcheckconnections && !$justreload) {
	$fh=&start_logging();

	&log_machine_info($fh);
	&clean_tmp($fh);
	&clean_lonIDs($fh);
	&check_httpd_logs($fh);
	&rotate_lonnet_logs($fh);
	&rotate_other_logs($fh);
    }
    if (!$justcheckconnections && !$justreload) {
	&checkon_daemon($fh,'lonmemcached',40000);
	&checkon_daemon($fh,'lonsql',200000);
	if ( &checkon_daemon($fh,'lond',40000,'USR1') eq 'running') {
	    &checkon_daemon($fh,'lond',40000,'USR2');
	}
	&checkon_daemon($fh,'lonc',40000,'USR1');
        &checkon_daemon($fh,'lonmaxima',40000);
        &checkon_daemon($fh,'lonr',40000);
    }
    if ($justreload) {
	&checkon_daemon($fh,'lond',40000,'USR2');
	&checkon_daemon($fh,'lonc',40000,'USR2');
    }
    if ($justcheckconnections) {
	&test_connections($fh);
    }
    if (!$justcheckdaemons && !$justcheckconnections && !$justreload) {
	&check_delayed_msg($fh);
	&finish_logging($fh);
	&log_simplestatus();
        &write_loncaparevs();
        &write_serverhomeIDs();
	&write_checksums();
	if ($totalcount>200 && !$noemail) { &send_mail(); }
    }
}

&main();
1;