mysqldump output to log4perl

Question

I have a Perl script that uses log4perl to log everything to file. The config for log4perl is stored in an external file.

This script runs the mysqldump command using qx. The output of the mysqldump command is printed to screen (i assume STDERR), but not to log file.

I would like to direct the output of mysqldump (and any other stmt that prints to screen) to log4perl log file.

I am not sure if this involves using something other than qx, or changing the log4perl config.

Note: i have seen some online examples of this, but they all use log4perl easy-config.

Here is the log4perl config file -

log4perl.rootLogger              = DEBUG, SCREEN, file
log4perl.appender.SCREEN         = Log::Log4perl::Appender::Screen
log4perl.appender.SCREEN.stderr  = 0
log4perl.appender.SCREEN.layout  = Log::Log4perl::Layout::PatternLayout
log4perl.appender.SCREEN.layout.ConversionPattern = %d %r %p %F{1} %M{1}.%L - %m%n
log4perl.appender.file          = Log::Log4perl::Appender::File
log4perl.appender.file.filename = log/mbackup.log
log4perl.appender.file.mode     = append
log4perl.appender.file.layout   = Log::Log4perl::Layout::PatternLayout
log4perl.appender.file.layout.ConversionPattern = %d %r %p{5} %F{1} %M{1}.%L - %m%n

Here is the perl script -

use strict;
use warnings 'FATAL' => 'all';
use Sys::Hostname;
use Log::Log4perl;

my $log_conf = "log4perl.conf";
Log::Log4perl::init($log_conf);
my $logp        = Log::Log4perl->get_logger();
my $dirTemp     = "temp";
my $fileTemp    = "temp_backup.gz";
my $dbSchema = 'test';
my $dbToken01 = 'root';
my $dbToken02 = 'haha';

sub create_backup {
    $logp->info("creating temp mysqldump...");
    my $backupCmd = "mysqldump -R --triggers -u $dbToken01 -p$dbToken02 -v --quick --single-transaction $dbSchema | gzip > $dirTemp/$fileTemp";
    qx($backupCmd);
}

#main
$logp->info("start backup script");
eval {
    create_backup();
};
if ($@) {
    $logp->error( 'error: ', $@ );
}
$logp->info("end backup script");

Here is the script output -

[root@localhost perl]# perl test.pl
2013/04/24 16:35:33 3 INFO test.pl main::.22 - start backup script
2013/04/24 16:35:33 4 INFO test.pl create_backup.16 - creating temp mysqldump...
-- Connecting to localhost...
-- Disconnecting from localhost...
2013/04/24 16:35:33 22 INFO test.pl main::.29 - end backup script

Clarification - When i said output, i meant the stderr output of the mysqldump command. I want all the text output of the mysqldump command, that is written on the screen, to be sent to the log4perl log file.

Answer 1

If you want to do both: Log the mysqldump and gzip you can do something like this:

By modifying sub create_backup

sub create_backup {
    my $sqlDumpFile = "$dirTemp/$fileTemp";
    $logp->info("creating temp mysqldump...");

    my $backupCmd = "mysqldump -R --triggers -u $dbToken01 -p$dbToken02 -v --quick --single-transaction $dbSchema 2>&1 | tee $sqlDumpFile";
    my $dumpOutput = `$backupCmd`;
    $logp->info($dumpOutput);
    `gzip $sqlDumpFile`; # note you will have renamed this file to "filename".gz
}

Update

If you want to only log Error then you can do something like this.

IPC::Run can make your life easier here.

sub create_backup {
    require IPC::Run qw(run); # or load this at the top of you script...
    my ($in, $out, $err);
    my $backupCmd = "mysqldump";
    my $sqlDumpFile = "$dirTemp/$fileTemp";

    $logp->info("creating temp mysqldump...");

    run([$backupCmd, '-R', '--triggers', '-u', $dbToken01, '-p', $dbToken02, 
      '-v', '--quick', '--single-transaction', $dbSchema, '>', $sqlDumpFile],
      \$in, \$out, \$err);

    if( $err ) {
        $logp->info($err);
        # do other stuff?
        # Eg. `unlink($sqlDumpFile);            
    } else {
        `gzip $sqlDumpFile`; # note you will have renamed this file to "filename".gz
    }
}