NAME

Net::PDSH - Perl extension for parallel distributed shell

SYNOPSIS

 use Net::PDSH;

 my $pdsh = Net::PDSH->new;

 $pdsh->pdsh("remotehost", "/bin/ls");

 cmd( [
  { 
   user => 'user',
   host => 'host.name,host.name,...',
   command => 'command',
   args => [ '-arg1', '-arg2' ],
   stdin_string => "string\n",
  },
  { 
   user => 'user',
   host => 'host.name,host.name,...',
   command => 'command',
   args => [ '-arg1', '-arg2' ],
   stdin_string => "string\n",
  }
  ]
);

DESCRIPTION

Simple wrappers around pdsh commands.

cmd

Calls pdsh in batch mode. Throws a fatal error if data occurs on the command's STDERR. Returns any data from the command's STDOUT.

If using the hashref-style of passing arguments, possible keys are:

host (requried)
command (required)
args (optional, arrayref)
stdin_string (optional) - written to the command's STDIN

set_batch_mode

Executes pdsh in batchmode

Input: 0/1

set_credentials

Executes pdsh under a given user. All the further commands would be executed as that user.

Input: username

EXAMPLE

my @cmd_arr = (
{ "hostname" => "remotehost1,remotehost2",
  "command" =>  ["/bin/cat", "/tmp/fsck.log", "/etc/hosts", ],
},
{ "hostname" => "remotehost3",
  "command" =>  ["/bin/cat", "/etc/sysconfig/network",],
},
);
my %pids = $pdsh->cmd(@cmd_arr);

This would execute "cat /tmp/fsck.log /etc/hosts" on remotehost1 and remotehost2
and it would execute "cat /etc/sysconfig/network" on remotehost3

It would return the output in %pids hash table where keys are pids and values are
output contents

FREQUENTLY ASKED QUESTIONS

Q: How do you supply a password to connect with pdsh within a perl script using the Net::PDSH module?

A: You don't (at least not with this module). Use RSA or DSA keys. See the quick help in the next section and the ssh-keygen(1) manpage.

A #2: See Net::SSH::Expect instead.

GENERATING AND USING SSH KEYS

1 Generate keys

Type:

ssh-keygen -t rsa

And do not enter a passphrase unless you wanted to be prompted for one during file copying.

Here is what you will see:

$ ssh-keygen -t rsa
Generating public/private rsa key pair.
Enter file in which to save the key (/home/User/.pdsh/id_rsa):
Enter passphrase (empty for no passphrase):
Enter same passphrase again:

Your identification will be saved in /home/User/.ssh/id_rsa
Your public key will be saved in /home/User/.ssh/id_rsa.pub

2 Copy public to machines you want to upload to

id_rsa.pub is your public key. Copy it to ~/.ssh on target machine.

Put a copy of the public key file on each machine you want to log into. Name the copy authorized_keys (some implementations name this file authorized_keys2)

Then type:

chmod 600 authorized_keys

Then make sure your home dir on the remote machine is not group or world writeable.

AUTHORS

Aditya Pandit <adityaspandit@gmail.com>

COPYRIGHT

This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

SEE ALSO

Net::SSH::Perl, Net::SSH::Expect, Net::SSH2, IPC::PerlSSH, pdsh(1)