libvirt users - Dec 2012 - Need help regarding perl sys::virt

Hi,
                I wanted to use perl Sys::Virt (which uses libvirt) to remotely
connect KVM hypervisor. As a start I tried following simple script(KVM.pl) but I
am getting following error.
First it will ask for authentication which I am providing to it manually then it
fails. Do I need to do some configuration on KVM hypervisor before executing
this script? Any help is appreciated.

bash-3.2$ perl KVM.pl
root at 10.238.132.125's password:
Unable to open connection to qemu+ssh://root at
10.238.132.125/system?no_verify=1: End of file while reading data: Warning:
Perm: Input/output error8.132.125' (RSA) to the list of known hosts.
Can't call method "list_domains" on an undefined value at KVM.pl
line 21.
bash-3.2$

bash-3.2$ cat KVM.pl

use strict;
use warnings;
use Sys::Virt;
use Data::Dump qw(dump);

my $user = "root";
my $host = <some_host>;

my $uri = "qemu+ssh://root\@$host/system?no_verify=1";

my $vmm;
eval {
  $vmm = Sys::Virt->new(uri => $uri, readonly => 1);
};
if ($@) {
    print "Unable to open connection to $uri: " . $@->message .
"\n";
}

for my $dom ($vmm->list_domains, $vmm->list_defined_domains) {
  ## see perldoc Sys::Virt::Domain
  print "name: ", $dom->get_name, "\n";
  print "uuid: ", $dom->get_uuid_string(), "\n";
  ## $dom->get_info returns a hash reference
  dump $dom->get_info;
  print "\n";
}

Regards,
Rawat
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On Tue, Dec 11, 2012 at 12:46:55PM +0000, Rawat, Vishwanath
wrote:
> Hi,
>                 I wanted to use perl Sys::Virt (which uses libvirt) to
remotely connect KVM hypervisor. As a start I tried following simple
script(KVM.pl) but I am getting following error.
> First it will ask for authentication which I am providing to it manually
then it fails. Do I need to do some configuration on KVM hypervisor before
executing this script? Any help is appreciated.
> 
> bash-3.2$ perl KVM.pl
> root at 10.238.132.125's password:
> Unable to open connection to qemu+ssh://root at
10.238.132.125/system?no_verify=1: End of file while reading data: Warning:
Perm: Input/output error8.132.125' (RSA) to the list of known hosts.

This is showing that libvirt failed to connect to the remote host.
This is not likely to be related to the Perl bindings. You should
check the same conection using virsh. eg

  virsh -c qemu+ssh://root at 10.238.132.125/system?no_verify=1 uri
> Can't call method "list_domains" on an undefined value at
KVM.pl line 21.
This error is because you failed to connect, but your script ignored
the error and carried on running, instead of exiting.
> bash-3.2$
> 
> bash-3.2$ cat KVM.pl
> 
> use strict;
> use warnings;
> use Sys::Virt;
> use Data::Dump qw(dump);
> 
> my $user = "root";
> my $host = <some_host>;
> 
> my $uri = "qemu+ssh://root\@$host/system?no_verify=1";
> 
> my $vmm;
> eval {
>   $vmm = Sys::Virt->new(uri => $uri, readonly => 1);
> };
> if ($@) {
>     print "Unable to open connection to $uri: " . $@->message
. "\n";
You need to exit at this point, since you have no valid connection
> }
> 
> for my $dom ($vmm->list_domains, $vmm->list_defined_domains) {
>   ## see perldoc Sys::Virt::Domain
>   print "name: ", $dom->get_name, "\n";
>   print "uuid: ", $dom->get_uuid_string(), "\n";
>   ## $dom->get_info returns a hash reference
>   dump $dom->get_info;
>   print "\n";
> }
> 

Daniel
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