execute remote perl script via ssh

vinoth.ree has asked for the wisdom of the Perl Monks concerning the following question:

Hello all,

I have a perl script on unix server and running it from windows machine. I have already synced the public key generated from windows machine to unix server so it does not ask for password.

ssh.exe username@xxx.xxx.xxx.xxx /fullpath/check_user_exists.pl userna
+me
[download]

The remote perl script does checks weather the username name exists in a csv file in the unix server that's it. If it exists it exits with 0 otherwise 1.

This is run by all the users in my team it works most of the users for particular user it does not works. When I run this command via command line manually it return 0, but when I call via perl script it returns 255.

What could be the issue? how to debug this issue?

This is how i call this command locally from a perl script on windows side.

sub executeCommand{
  my $command = join ' ', @_;
  $prot and print("Command: $command\n");
  my $response = qx($command 2>&1);
  my $status = $? >> 8;
  return ($status, $response);
}

my @src_cmd = ('ssh.exe ', $ssh_user.'@'.$hostname ." /fullpath/check_
+user_exists.pl " . "$user");
my ($status, $output) = &executeCommand(@src_cmd);
[download]

All is well. I learn by answering your questions...

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Re: execute remote perl script via ssh by haukex (Archbishop) on Jul 26, 2020 at 09:58 UTC
Have you looked at the values of `$ssh_user`, `$hostname`, and `$user` via e.g. Data::Dumper? Do you know whether `ssh.exe` is always in the `PATH`? Also, you should definitely be using a module to run external commands more safely, for example in this case I think IPC::Run3 might be appropriate (more info and sample code here). At the very least, use Win32::ShellQuote to build the command line.	[reply] [d/l] [select]
Re^2: execute remote perl script via ssh by vinoth.ree (Monsignor) on Jul 26, 2020 at 12:31 UTC
Hi haukex I can see the value of `$ssh_user, $hostname, and $user` for the particular user `I will try with IPC::Run3 instead of using qx().` *All is well. I learn by answering your questions...*	[reply] [d/l] [select]
Re^3: execute remote perl script via ssh by vinoth.ree (Monsignor) on Aug 10, 2020 at 19:48 UTC
Hi Monks, I have identified the issue for that particular user, As I already said we use public key method to auto login without asking for the password, there is the problem, his user account is being shared by another user, so his private key is not secure and ssh fails with below error `debug3: Bad permissions. Try removing permissions for user: XXXXX on f +ile C:\\Users\\XXXXXX/.ssh/id_rsa. @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ @ WARNING: UNPROTECTED PRIVATE KEY FILE! @ @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ Permissions for 'C:\\Users\\XXXXXX/.ssh/id_rsa' are too open. It is required that your private key files are NOT accessible by other +s. This private key will be ignored.` [download] After removing the permission for the other user, it works fine. *All is well. I learn by answering your questions...*	[reply] [d/l]
Re: execute remote perl script via ssh by jcb (Parson) on Jul 27, 2020 at 03:06 UTC
If it works for most users, but fails for one particular case, you probably have either a problem with that user's name containing shell metacharacters, or something is wrong with the `check_user_exists.pl` script on the server.	[reply] [d/l]
Re: execute remote perl script via ssh by karlgoethebier (Abbot) on Jul 26, 2020 at 18:32 UTC
ssh -v ŤThe Crux of the Biscuit is the Apostropheť `perl -MCrypt::CBC -E 'say Crypt::CBC->new(-key=>'kgb',-cipher=>"Blowfish")->decrypt_hex($ENV{KARL});'`Help	[reply] [d/l]
Re: execute remote perl script via ssh by perlfan (Vicar) on Jul 26, 2020 at 22:04 UTC
Make it easy on yourself and set up an ssh config. It might be worth using cygwin or even Docker and a super light alpine image running cron.	[reply]
Re^2: execute remote perl script via ssh by syphilis (Archbishop) on Jul 27, 2020 at 00:38 UTC
Make it easy on yourself and set up an ssh config. It might be worth using Cygwin On my Windows 7 box I use Cygwin in precisely that way for ssh connections to various nix machines. It works well. I envisage that it would also work equally well from an MSYS2 installation. For scripted communication between Windows and nix I usually use Net::SSH2 or Net::SSH::Any (which utilizes Net::SSH2 via a more user-friendly interface), run from a native Windows cmd.exe shell. Cheers, Rob	[reply]

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