#!/usr/bin/perl

################################################################################
#
# Perl implementation of rsync-backup.sh
#
# 2014-11-17 - MSL
#
################################################################################

use warnings;
use strict;
use v5.10;

use Log::Log4perl qw(:easy);
Log::Log4perl->easy_init(       {       level => $DEBUG, file  => ">>$0.log"},
                                                        {       level => $DEBUG, file  => "STDOUT"      }       );

INFO("$0 - Begin Program");

################################################################################
#
# Define backup volumnes
#
################################################################################

my %backup_vols;  # key = partition UUID

# entry 00
$backup_vols{'cc284958-7a1a-4519-b5f6-a068ff1397dc'}->{'EXCLUDES'}   = "/root/etc/rsync-backup/excludes.conf";

# Volume: /dev/sdb1, 8:17, 750126104576, 6f1a98f5-70ea-4870-ae51-53e52f0383af, ext2, backup001
$backup_vols{'6f1a98f5-70ea-4870-ae51-53e52f0383af'}->{'EXCLUDES'}   = "/root/etc/rsync-backup/excludes.conf";

# Volume: /dev/sdb1, 8:17, 1000203837440, 6720f72b-86ad-4568-b8dc-b22f69cf2923, btrfs, backup02
$backup_vols{'6720f72b-86ad-4568-b8dc-b22f69cf2923'}->{'EXCLUDES'}   = "/root/etc/rsync-backup/excludes-1tb.conf";

# Volume: /dev/sdb1, 8:17, 999500546048, ed4f4207-7ee5-4263-8b2e-4267a4abf1f9, btrfs, backup03
$backup_vols{'ed4f4207-7ee5-4263-8b2e-4267a4abf1f9'}->{'EXCLUDES'}   = "/root/etc/rsync-backup/excludes-1tb.conf";


##############################################################################################
#
#  Occasionally changed system configuration variables
#
##############################################################################################

# bin  boot  cgroup  dev  etc  home  lib  lost+found  media  mnt  opt  proc  root  run  sbin  selinux  srv  storage  sys  tmp  usr  var
my $SOURCES="/bin /boot /etc /home /lib /opt /root /sbin /storage /usr /var";

my $FS_MOUNTPOINT = q{/mnt};

my $VERBOSE = q{-v};

################################################################################
#
# Utility Paths and options.
#
################################################################################

my $BIN_LSBLK = qx{ which lsblk };
chomp $BIN_LSBLK;
INFO ("lsblk=$BIN_LSBLK");

my $LSBLKOPTS = q{ -bnp -o KNAME,MAJ:MIN,SIZE,UUID,FSTYPE,LABEL };

my $LSBLK_CMD = qq{ $BIN_LSBLK $LSBLKOPTS };


################################################################################
#
# Step 1:  Let's find out what backup volume ( if any ) is mounted.
# 
################################################################################


#  Initialize Target variables
my ( $T_KNAME, $T_MAJ_MIN, $T_SIZE, $T_UUID, $T_FSTYPE, $T_LABEL ) = ();


#  Loop through lsblk
foreach my $line ( qx{ $LSBLK_CMD } ) {

        #  while we don't have a T_UUID
        if ( not $T_UUID ) { 

                #  Extract data from lsblk row
                my      ($KNAME, $MAJ_MIN, $SIZE, $UUID, $FSTYPE, $LABEL) = split(/\s+/,$line);

                # if we match one of the UUIDs on our list
                if ( grep (/$UUID/, sort keys %backup_vols) ) {  

                        #  save off the device information
                        ($T_KNAME, $T_MAJ_MIN, $T_SIZE, $T_UUID, $T_FSTYPE, $T_LABEL ) = split(/\s+/,$line);

                };  # if

        }; # if not T_UUID

} # foreach $line


#  Check to make sure we have a device attached

if ( not $T_UUID ) { 
        FATAL("Fatal Error:  Could not find a drive to use.");
        FATAL qx{ echo "Output of: $LSBLK_CMD"; $LSBLK_CMD };
        FATAL "$0 - End Program";
        exit 1;
}


INFO "Volume: $T_KNAME, $T_MAJ_MIN, $T_SIZE, $T_UUID, $T_FSTYPE, $T_LABEL";

################################################################################
#
# Utility Paths and options (continued)
#
################################################################################

my $BIN_MOUNT = qx{ which mount };
chomp $BIN_MOUNT;
INFO ("mount=$BIN_MOUNT");

my $MOUNTOPTS = qq{-o context="system_u:object_r:removable_t:s0" };

my $CMD_MOUNT = qq{ $BIN_MOUNT $VERBOSE -t $T_FSTYPE -U $T_UUID $FS_MOUNTPOINT $MOUNTOPTS };

################################################################################

my $BIN_RSYNC = qx{ which rsync };
chomp $BIN_RSYNC;
INFO ("rsync=$BIN_RSYNC");

my $RSYNCOPTS = qq{-a $VERBOSE --delete --delete-excluded --exclude-from=$backup_vols{$T_UUID}->{'EXCLUDES'} };

my $CMD_RSYNC = qq{ $BIN_RSYNC $RSYNCOPTS $SOURCES $FS_MOUNTPOINT };

################################################################################

my $BIN_UMOUNT = qx{ which umount };
chomp $BIN_UMOUNT;
INFO ("umount=$BIN_UMOUNT");

my $UMOUNTOPTS = qq{}; 

my $CMD_UMOUNT = qq{ $BIN_UMOUNT $VERBOSE $FS_MOUNTPOINT }; 


##############################################################################################
#
# Subroutine: execute_cmd( qq{ some command text $variable } );
#
##############################################################################################
sub execute_cmd {

        my $cmd = shift;
        INFO "    Command='$cmd'";

        my $retval = qx{$cmd 2>&1}; # || sad_trombone
        DEBUG "CHILD_ERROR_NATIVE=${^CHILD_ERROR_NATIVE}";

        DEBUG "----  Command Output  ----";
        DEBUG "$retval";
        DEBUG "--------------------------";

        return ${^CHILD_ERROR_NATIVE};

}; # sub execute_cmd


##############################################################################################
#
#  Begin
#
##############################################################################################

INFO "Beginning rsync backup of data to portable drive.";
INFO "--------------------------------------------------------------------------------";
INFO "    Backup up directories: $SOURCES";
INFO "    to: $FS_MOUNTPOINT";
INFO "    with rsync options: $RSYNCOPTS";

INFO "----  Mounting Portable Drive  ---";
my $rtn_code = execute_cmd ( $CMD_MOUNT );

if ( $rtn_code == 0 ) {
        INFO "----  Beginning Sync Operation  ---";
        execute_cmd ( $CMD_RSYNC );
};

INFO "----  Unmounting Portable Drive  ---";
execute_cmd ( $CMD_UMOUNT ); 

INFO("$0 - End Program");


##############################################################################################
__END__