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

Hi Monks, Found that this link for asking any doubts regarding perl. I have automated a verifying processes are runing or not on a server by below code

use strict;
my @pslist = ("ps -ef|grep psname=abc","ps -ef|grep psname=def",...,);
foreach my $ps(@pslist) {
    print "Checking for the Process,";
    my $ps1 = `$ps`;
    if($ps1 =~ /psname=abc/) {
          print "\"abc\" is running Fine\n";
         }
    elsif($ps1 =~ /psnameame=def/) {
          print "\"def\" is running fine\n";
        }
    elsif($ps1 =~ /psname=xyz/) {
         print "\xyz\" is running Fine\n";
        }
    else { print "None of the processes are running\n"; }
   }

[download]
This is working as expected, i just wanted to check different processes on different servers, i use to login to server by putty via ssh for verifying processes for a single server.in order to verify different processes on different unix servers, please suggest me the way to do this.
  • Comment on How to automate login to different servers via ssh and check is some specific processes are running or not.
  • Download Code

Replies are listed 'Best First'.
Re: How to automate login to different servers via ssh and check is some specific processes are running or not.
by keszler (Priest) on Dec 12, 2014 at 15:37 UTC
    You might want to look into Rex, and specifically Rex HowTo: Listing all running processes. 
    use Rex::Commands::Process;

user "my-user";
password "my-password";
pass_auth;

group myserver => "mywebserver", "mymailserver", "myfileserver";

desc "List all running processes";
task "ps", group => "myserver", sub {

   for my $process ( ps() ) {
      say "command: " . $process->{"command"};
      say "pid    : " . $process->{"pid"};
      say "user   : " . $process->{"user"};
   }

};

    [download]
[reply]
[d/l]
Re: How to automate login to different servers via ssh and check is some specific processes are running or not.
by Anonymous Monk on Dec 12, 2014 at 12:46 UTC

    To clarify, do you want to know how to log on to remote servers to execute the code that you have posted?

[reply]
      Thanks for the reply, for executing command on remote host we can use ssh user@server path/script or unix command,but i don't want to type a command each time. For verifying diff processes on diff servers, i just wanted to write a script to do that. For ex: if in server1 i need to check 10 processes and in server 2 i need to check for 20 processes and for server 3, for this i wanted to include whole thing in a script to do this.
[reply]

        To avoid supplying ssh password, use a ssh key with a key-agent. Also, do a search around these parts related to logging on to a ssh host & running commands.

[reply]

        Use some kind of configuration -- hash, external files, __DATA__, etc -- to associate processes to a server ... 

        # Untested, incomplete code.

my %map =
  ( 'host-p' => [qw[ cron apache ]]
  , 'host-q' => [qw[ ntpd ]]
  );

for my $host ( sort keys %map )
{
  #  Log on $host at this point.

  #  Check processes.
  foreach my $proc ( @{ $map{ $host } } )
  {
    printf qq[%s: %3s running]
      , $proc
      , check_proc( $proc ) ? '' : 'not' ;
  }

  #  Log off.
}

sub check_proc
{
  my ( $proc ) = @_;

  my $ps = make_ps( $proc );
  my $res = qx[ $ps ];
  # Check $? for cause of failure if you care.

  return
    defined $res && $res =~ m{ \b psname = $proc \b }x;
}

sub make_ps
{
  return sprintf q[ps -ef | grep psname=%s] , $_[0] ;
}

        [download]

        Your process checking looks too complicated; there might be OS specific commands/options that won't require filtering of ps run itself. Perhaps some native Perl module may be in existence for the purpose.

[reply]
[d/l]
[select]

Back to Seekers of Perl Wisdom