Why does this not work? - Can't call method on an undefined value!!!

Batistuta_g_2000 has asked for the wisdom of the Perl Monks concerning the following question:

Hi, Am relatively new to perl scripting and am tring to write a script to get the vm names for certain ipaddresses on an ESXi host:


#!/usr/bin/perl -w
use strict;
use warnings;
use Data::Dumper;
use VMware::VIRuntime;

my %opts = (
   vm => {
      type => "=s",
      help => "Name for the VM",
      required => 1,
   },
   ip => {
      type => "=s",
      help => "Name for the IP",
      required => 1,
   },

);

Opts::add_options(%opts);
Opts::parse();
Opts::validate();
Util::connect();

my $ip_address = Opts::get_option('ip');
my $vmname = Opts::get_option('vm');
my %filter=(name=>$vmname);
my $vm = Vim::find_entity_view(view_type => 'VirtualMachine',filter=>\
+%filter);
  foreach my $ip (@{$vm->guest->net->ipConfig->ipAddress})
    {
      my $ip_address = Opts::get_option('ip');
      my $ipadd = ref $ip;
      if ($ipadd eq $ip_address)
      {
        print "Found $ip for $vmname \n";
      }
#  }
}
Util::disconnect();
[download]

Getting error: Can't call method ipConfig on and undefined value? Is referencing an MOB reference but I cant see a problem, are there any obvious "Perl" problems with it? Thanks

Comment on Why does this not work? - Can't call method on an undefined value!!! Download Code

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Re: Why does this not work? - Can't call method on an undefined value!!! by moritz (Cardinal) on May 06, 2013 at 17:16 UTC
The error message means that `$vm->guest->net` is undefined. I'm not familiar enough with the VMWare client API to tell when that is the case, but it seems it can happen. Perl 6 - the future is here, just unevenly distributed	[reply] [d/l]
Re: Why does this not work? - Can't call method on an undefined value!!! by graff (Chancellor) on May 07, 2013 at 02:31 UTC
VMware is a topic about which I know virtually nothing. But apart from that... Your code is using modules that don't currently exist on CPAN. Are you using home-grown modules? If so, then you'll have to look more closely at your own local code base for "VMware::VIRuntime" (assuming it's documented), to see whether that helps to figure out what the problem is. If you're using modules that used to exist on CPAN, then you should probably look for more recent modules that are currently supported (and might do a better job in terms of what you want to get done). Having just browsed CPAN for "VMware" and related things, I noticed that the "See Also" sections of some modules make reference to other modules (like "VMware::VmPerl") that seem to have gone missing, so this is probably a somewhat volatile domain in terms of CPAN module life-spans. But maybe the CPAN results for "VmWareESX" might be relevant? (I wouldn't have a clue whether they are or not.)	[reply]
Re: Why does this not work? - Can't call method on an undefined value!!! by LanX (Saint) on May 06, 2013 at 16:08 UTC
~~its `<code>` not `[code]`~~ done! =) Cheers Rolf ( addicted to the Perl Programming Language)	[reply] [d/l] [select]