From 2415dea5aa5ecc1542b3da7795c0b7c49b98f259 Mon Sep 17 00:00:00 2001
From: James Davidson <james.davidson@vyatta.com>
Date: Thu, 5 Apr 2012 17:52:08 -0700
Subject: Use rsyslog to trigger log rotation

The previous implementation of log rotation used an hourly cron job to
check log file size and possibly perform a rotation. If the logging
rate is high, this interval may allow for root file system space
exhustion.

Utilizing rsyslog's outchannel mechanism enables log rotation to be
initiated as soon as the log file becomes larger than its configured
size.

Fixes Bug 7807.
---
 scripts/system/vyatta_update_syslog.pl | 86 +++++++++++++++++++++++++++-------
 1 file changed, 69 insertions(+), 17 deletions(-)

(limited to 'scripts/system/vyatta_update_syslog.pl')

diff --git a/scripts/system/vyatta_update_syslog.pl b/scripts/system/vyatta_update_syslog.pl
index 1c4c6d46..3421d61a 100755
--- a/scripts/system/vyatta_update_syslog.pl
+++ b/scripts/system/vyatta_update_syslog.pl
@@ -23,22 +23,42 @@
 use strict;
 use lib "/opt/vyatta/share/perl5";
 use Vyatta::Config;
+use File::Basename;
 use File::Compare;
+use File::Temp qw/ tempfile /;
 
 my $SYSLOG_CONF  = '/etc/rsyslog.d/vyatta-log.conf';
-my $SYSLOG_TMP   = "/tmp/rsyslog.conf.$$";
-my $MESSAGES     = '-/var/log/messages';
+my $SYSLOG_TMPL  = "/tmp/rsyslog.conf.XXXXXX";
+my $MESSAGES     = '/var/log/messages';
 my $CONSOLE      = '/dev/console';
+my $LOGROTATE_CFG_DIR = '/opt/vyatta/etc/logrotate';
 
 my %entries = ();
 
 die "$0 expects no arguments\n" if (@ARGV);
 
-sub add_entry {
+sub add_target_selector {
     my ( $selector, $target ) = @_;
 
-    $entries{$target} = [] unless $entries{$target};
-    push @{ $entries{$target} }, $selector;
+    $entries{$target}{selector} = [] unless $entries{$target}{selector};
+    push @{ $entries{$target}{selector} }, $selector;
+}
+
+sub set_target_param {
+    my ( $config, $level, $target, $param ) = @_;
+    my $path = "$level archive $param";
+
+    if (! $config->exists($path)) {
+        my @tmpl = $config->parseTmpl($path);
+        $entries{$target}{$param} = $tmpl[2];
+    } else {
+        $entries{$target}{$param} = $config->returnValue($path);
+    }
+}
+
+sub get_target_param {
+    my ( $target, $param ) = @_;
+    return $entries{$target}{$param};
 }
 
 # This allows overloading local values in CLI
@@ -57,10 +77,25 @@ sub read_config {
         $facility = $facmap{$facility} if ( $facmap{$facility} );
         $loglevel = '*' if ( $loglevel eq 'all' );
 
-        add_entry( $facility . '.' . $loglevel, $target );
+        $entries{$target} = {} unless $entries{$target};
+        add_target_selector( $facility . '.' . $loglevel, $target );
+    }
+
+    # This is a file target so we set size and files
+    if ($target =~ m:^/var/log/:) {
+        set_target_param($config, $level, $target, 'size');
+        set_target_param($config, $level, $target, 'files');
     }
 }
 
+sub print_outchannel {
+    my ( $fh, $channel, $target, $size ) = @_;
+    # Force outchannel size to be 1k more than logrotate config to guarantee rotation
+    $size = ($size + 5) * 1024;
+    print $fh "\$outchannel $channel,$target,$size,/usr/sbin/logrotate ${LOGROTATE_CFG_DIR}/$channel\n";
+    print $fh join( ';', @{ $entries{$target}{selector} } ), " \$$channel\n";
+}
+
 my $config = new Vyatta::Config;
 $config->setLevel("system syslog");
 
@@ -68,8 +103,8 @@ read_config( $config, 'global', $MESSAGES );
 
 # Default syslog.conf if no global entry
 unless (%entries) {
-    add_entry( '*.notice', $MESSAGES );
-    add_entry( 'local7.*', $MESSAGES );
+    add_target_selector( '*.notice', $MESSAGES );
+    add_target_selector( 'local7.*', $MESSAGES );
 }
 
 read_config( $config, 'console', $CONSOLE );
@@ -86,23 +121,40 @@ foreach my $user ( $config->listNodes('user') ) {
     read_config( $config, 'user $user', $user );
 }
 
-open my $out, '>', $SYSLOG_TMP
-  or die "Can't open $SYSLOG_TMP: $!";
+my ($out, $tempname) = tempfile($SYSLOG_TMPL, UNLINK => 1)
+  or die "Can't create temp file: $!";
 
+my $files;
+my $size;
 foreach my $target ( keys %entries ) {
-    print $out join( ';', @{ $entries{$target} } ), "\t$target\n";
+    if ($target eq $MESSAGES) {
+        $size = get_target_param($target, 'size');
+        $files = get_target_param($target, 'files');
+        print_outchannel($out, 'global', $target, $size);
+        system("sudo /opt/vyatta/sbin/vyatta_update_logrotate.pl $files $size 1") == 0
+            or die "Can't genrate global log rotation config: $!";
+    } elsif ($target =~ m:^/var/log/user/:) {
+        my $file = basename($target);
+        $size = get_target_param($target, 'size');
+        $files = get_target_param($target, 'files');
+        print_outchannel($out, 'file_' . $file, $target, $size);
+        system("sudo /opt/vyatta/sbin/vyatta_update_logrotate.pl $file $files $size 1") == 0
+            or die "Can't genrate global log rotation config: $!";
+    } else {
+        print $out join( ';', @{ $entries{$target}{selector} } ), "\t$target\n";
+    }
 }
 close $out
-  or die "Can't output $SYSLOG_TMP: $!";
+  or die "Can't output $tempname: $!";
 
 # Don't need to do anything, save time on boot
-if ( -e $SYSLOG_CONF && compare( $SYSLOG_CONF, $SYSLOG_TMP ) == 0 ) {
-    unlink($SYSLOG_TMP);
+if ( -e $SYSLOG_CONF && compare( $SYSLOG_CONF, $tempname ) == 0 ) {
+    unlink($tempname);
     exit 1;
 }
 
-system("sudo cp $SYSLOG_TMP $SYSLOG_CONF") == 0
-  or die "Can't copy $SYSLOG_TMP to $SYSLOG_CONF";
+system("sudo cp $tempname $SYSLOG_CONF") == 0
+  or die "Can't copy $tempname to $SYSLOG_CONF: $!";
 
-unlink($SYSLOG_TMP);
+unlink($tempname);
 exit 0;
-- 
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