$ssh{$host} = Net::OpenSSH->new($host, master_opts => [-i => "/path/to/key"]);
    if(defined $ssh{$host}) {
      print STDOUT "SSHD is back up. Continuing...\n";
    }
    else {
      print STDOUT "Still waiting for SSH. Retrying in 5 seconds...\n";
      sleep 5;
    }