#!/usr/bin/env perl
use warnings;
use strict;  

# Description: get information on lvm2 partitions

our $VERSION = '1.0';

# Linux lvm2
# Author: R. W. Rodolico
# Date:  2017-11-24

# get some information on lvm2

BEGIN {
   push @INC, shift;
}

use library;

# category we will use for all values found
# see sysinfo for a list of valid categories
my $CATEGORY = 'diskinfo';

# run the commands necessary to do whatever you want to do
# The library entered above has some helper routines
# validCommandOnSystem -- passed a name, returns the fully qualified path or '' if it does not exist
# cleanUp - passed a delimiter and a string, does the following (delimiter can be '')
#           chomps the string (removes trailing newlines)
#           removes all text BEFORE the delimiter, the delimiter, and any whitespace
#           thus, the string 'xxI Am x  a weird string' with a newline will become
#           'a weird string' with no newline

# now, return the tab delimited output (to STDOUT). $CATEGORY is the first
# item, name as recognized by sysinfo is the second and the value is
# the last one. For multiple entries, place on separate lines (ie, newline separated)

# check for commands we want to run
my %commands = ( 
                  'vgs' => '',
                  'pvs' => '',
                  'lvs' => ''
               );

# check the commands for validity
foreach my $command ( keys %commands ) {
   $commands{$command} = &validCommandOnSystem( $command );
}

# bail if we don't have the commands we need
exit 1 unless $commands{'lvs'};

my @output;
my @temp;
my $line;

my %pv;
my %vg;
my %lv;
my $name;

@output = qx( $commands{pvs} --units k --noheadings );
# this outputs several lines like the following
#  /dev/md0   vg-md0 lvm2 a--  5860147200.00k 6995968.00k
chomp @output;
foreach $line ( @output ) {
   @temp = split( /\s+/, $line );
   $name = $temp[1];
   $pv{$name}{'vg'} = $temp[2];
   $pv{$name}{'size'} = $temp[5];
   $pv{$name}{'size'} =~ s/k//;
   $pv{$name}{'size'} = int( $pv{$name}{'size'} );
   $pv{$name}{'free'} = $temp[5];
   $pv{$name}{'free'} =~ s/k//;
   $pv{$name}{'free'} = int( $pv{$name}{'free'} );
}

# following outputs something like this
#  vg-md0   1   9   0 wz--n- 5860147200.00k 6995968.00k
@output = qx( $commands{'vgs'} --units k --noheadings );
chomp @output;
foreach $line ( @output ) {
   @temp = split( /\s+/, $line );
   $name = $temp[1];
   $vg{$name}{'size'} = $temp[6];
   $vg{$name}{'size'} =~ s/k//;
   $vg{$name}{'size'} = int( $vg{$name}{'size'} );
   $vg{$name}{'free'} = $temp[7];
   $vg{$name}{'free'} =~ s/k//;
   $vg{$name}{'free'} = int( $vg{$name}{'free'} );
}

# outputs something like this
#  centos                      vg-md0 -wi-ao--   10485760.00k                                           
@output = qx( $commands{lvs} --units k --noheadings );
chomp @output;
foreach $line ( @output ) {
   @temp = split( /\s+/, $line );
   $name = $temp[1];
   $lv{$name}{'vg'} = $temp[2];
   $lv{$name}{'size'} = $temp[4];
   $lv{$name}{'size'} =~ s/k//;
   $lv{$name}{'size'} = int( $lv{$name}{'size'} );
}

my @results;

foreach $line ( keys %lv ) {
   push @results, "$CATEGORY\t$line\tsize\t" . $lv{$line}{'size'};
   push @results, "$CATEGORY\t$line\tfstype\tlvm2 lv";
   push @results, "$CATEGORY\t$line\tvg\t" . $lv{$line}{'vg'};
}

foreach $line ( keys %vg ) {
   push @results, "$CATEGORY\t$line\tsize\t" . $vg{$line}{'size'};
   push @results, "$CATEGORY\t$line\tused\t" . ( $vg{$line}{'size'} - $vg{$line}{'free'}) ;
   push @results, "$CATEGORY\t$line\tfstype\tlvm2 vg";
   my @components;
   foreach my $pv ( keys %pv ) {
      if ( $pv{$pv}{'vg'} eq $line ) {
         push @components, $pv;
      }
   }
   push @results, "$CATEGORY\t$line\tcomponents\t" . join( ' ', @components );
}

foreach $line ( keys %pv ) {
   push @results, "$CATEGORY\t$line\tsize\t" . $pv{$line}{'size'};
   push @results, "$CATEGORY\t$line\tfstype\tlvm2 pv";
}


print join( "\n", @results ) . "\n";

exit 0;