Pssh exited with error code 255

pssh(1) — Linux man page

pssh — parallel ssh program

Synopsis

Description

pssh is a program for executing ssh in parallel on a number of hosts. It provides features such as sending input to all of the processes, passing a password to ssh, saving output to files, and timing out.

The PSSH_NODENUM and PSSH_HOST environment variables are sent to the remote host. The PSSH_NODENUM variable is assigned a unique number for each ssh connection, starting with 0 and counting up. The PSSH_HOST variable is assigned the name of the host as specified in the hosts list. Note that sshd drops environment variables by default, so sshd_config on the remote host must include the line: AcceptEnv PSSH_NODENUM PSSH_HOST

Options

-h host_file —hosts host_file Read hosts from the given host_file. Lines in the host file are of the form [user@]host[:port] and can include blank lines and comments (lines beginning with «#»). If multiple host files are given (the -h option is used more than once), then pssh behaves as though these files were concatenated together. If a host is specified multiple times, then pssh will connect the given number of times. -H

«[user@]host[:port] [ [user@]host[:port ] . ]» Add the given host strings to the list of hosts. This option may be given multiple times, and may be used in conjunction with the -h option. -l user —user user Use the given username as the default for any host entries that don’t specifically specify a user. -p parallelism —par parallelism Use the given number as the maximum number of concurrent connections. -t timeout —timeout timeout Make connections time out after the given number of seconds. With a value of 0, pssh will not timeout any connections. -o outdir —outdir outdir Save standard output to files in the given directory. Filenames are of the form [user@]host[:port][.num] where the user and port are only included for hosts that explicitly specify them. The number is a counter that is incremented each time for hosts that are specified more than once. -e errdir —errdir errdir Save standard error to files in the given directory. Filenames are of the same form as with the -o option. -x args —extra-args args Passes extra SSH command-line arguments (see the ssh(1) man page for more information about SSH arguments). This option may be specified multiple times. The arguments are processed to split on whitespace, protect text within quotes, and escape with backslashes. To pass arguments without such processing, use the -X option instead. -X arg —extra-arg arg Passes a single SSH command-line argument (see the ssh(1) man page for more information about SSH arguments). Unlike the -x option, no processing is performed on the argument, including word splitting. To pass multiple command-line arguments, use the option once for each argument. -O options —options options SSH options in the format used in the SSH configuration file (see the ssh_config(5) man page for more information). This option may be specified multiple times. -A —askpass Prompt for a password and pass it to ssh. The password may be used for either to unlock a key or for password authentication. The password is transferred in a fairly secure manner (e.g., it will not show up in argument lists). However, be aware that a root user on your system could potentially intercept the password. -i —inline Display standard output and standard error as each host completes. —inline-stdout Display standard output (but not standard error) as each host completes. -v —verbose Include error messages from ssh with the -i and options. -I —send-input Read input and send to each ssh process. Since ssh allows a command script to be sent on standard input, the -I option may be used in lieu of the command argument. -P —print Display output as it arrives. This option is of limited usefulness because output from different hosts are interleaved.

Examples

Connect to host1 and host2, and print «hello, world» from each: pssh -i -H «host1 host2» echo «hello, world» Print «hello, world» from each host specified in the file hosts.txt: pssh -i -h hosts.txt echo «hello, world» Run a command as root with a prompt for the root password: pssh -i -h hosts.txt -A -l root echo hi Run a long command without timing out: pssh -i -h hosts.txt -t 0 sleep 10000 If the file hosts.txt has a large number of entries, say 100, then the parallelism option may also be set to 100 to ensure that the commands are run concurrently: pssh -i -h hosts.txt -p 100 -t 0 sleep 10000 Run a command without checking or saving host keys: pssh -i -H host1 -H host2 -x «-O StrictHostKeyChecking=no -O UserKnownHostsFile=/dev/null -O GlobalKnownHostsFile=/dev/null» echo hi Print the node number for each connection (this will print 0, 1, and 2): pssh -i -H host1 -H host1 -H host2 ‘echo $PSSH_NODENUM’

If you have a set of hosts that you connect to frequently with specific options, it may be helpful to create an alias such as: alias pssh_servers=»pssh -h /path/to/server_list.txt -l root -A» The ssh_config file can include an arbitrary number of Host sections. Each host entry specifies ssh options which apply only to the given host. Host definitions can even behave like aliases if the HostName option is included. This ssh feature, in combination with pssh host files, provides a tremendous amount of flexibility.

Exit Status

The exit status codes from pssh are as follows:

Syntax or usage error

At least one process was killed by a signal or timed out.

All processes completed, but at least one ssh process reported an error (exit status 255).

There were no ssh errors, but at least one remote command had a non-zero exit status.

Written by Brent N. Chun and Andrew McNabb .

Источник

PSSH error 255

Here’s what I’m trying to do. I’ve a number of Ubuntu servers (version 18 and 20), and I’m wanting to run the same script against several of them.

It’s my understanding that parallel-ssh will do the trick for me.

Here’s what I’ve done.

First things I did was install parallel-ssh using sudo apt-get install pssh

next I create to files. The first I created using sudo nano

I copied and pasted the following in and saved it:

# show system uptime

I saved that, and then created another using nano

This is text file that consists of several IP addresses set up as:

username IP_Address ​ with the username being our admin account and ip address being the Ubuntu servers.

then I an it using parallel-ssh -h pssh-hosts -A -P -I local_offer Tagged Items

Ensure AV Gear Plays Nice on the Corporate Network

Double checked that. IP address’s are correct.

Could also be a permission issue. You could follow this guide to get it working using key generation technique. https://www.cyberciti.biz/cloud-computing/how-to-use-pssh-parallel-ssh-program-on-linux-unix/ Opens a new window

nano is safe, but cut and paste might be your problem.

You may have introduced CR/LF into your files on Linux, which expects to see LF only as its end of line.

Maybe the issue is with the password. I’m guessing successful logins are NOT logged on the target machines.

You might try allocating a tty by passing the » -t » ssh option in your pssh command. If that doesn’t work try » -tt «.

From the ssh man page:

«-t Force pseudo-tty allocation. This can be used to execute arbitrary screen-based programs on a remote machine, which can be very useful, e.g. when implementing menu services. Multiple -t options force tty allocation, even if ssh has no local tty.»

I’d like to use my passphrase protected SSH key when performing tasks with parallel-ssh (and related tools). However, I can’t get this to work.

All the documentation, regarding parallel-ssh, show that I should be able to use --askpass or -A to do this:

-A
--askpass
      Prompt  for  a  password  and pass it to ssh.  The password may be 
      used for either to unlock a key or for password authentication.  The 
      password is transferred in a fairly secure manner (e.g., it will not 
      show up in argument lists).  However, be aware that a root user on 
      your system could potentially intercept the password.

However, when I enter the passphrase of my key, it doesn’t work:

$ parallel-ssh --hosts=machines --user=my_user --askpass 
    --timeout=0 --inline -v 'sudo apt-get update'
Warning: do not enter your password if anyone else has superuser
privileges or access to your account.
Password: 
[1] 09:59:36 [FAILURE] amritiii Exited with error code 255
Stderr: Enter passphrase for key '/home/nhaigh/.ssh/id_rsa': 
Permission denied (publickey,password).
[2] 09:59:37 [FAILURE] gbdev Exited with error code 255
Stderr: Enter passphrase for key '/home/nhaigh/.ssh/id_rsa': 
Permission denied (publickey,password).
[3] 09:59:37 [FAILURE] code Exited with error code 255
Stderr: Enter passphrase for key '/home/nhaigh/.ssh/id_rsa': 
Permission denied (publickey,password).
[4] 09:59:37 [FAILURE] apollo Exited with error code 255
Stderr: Enter passphrase for key '/home/nhaigh/.ssh/id_rsa': 
Permission denied (publickey,password).
[5] 09:59:37 [FAILURE] odin Exited with error code 255
Stderr: Enter passphrase for key '/home/nhaigh/.ssh/id_rsa': 
Permission denied (publickey,password).
[6] 09:59:37 [FAILURE] hathor Exited with error code 255
Stderr: Enter passphrase for key '/home/nhaigh/.ssh/id_rsa': 
Permission denied (publickey,password).
[7] 09:59:37 [FAILURE] ldap Exited with error code 255
Stderr: Enter passphrase for key '/home/nhaigh/.ssh/id_rsa': 
Permission denied (publickey,password).
[8] 09:59:37 [FAILURE] thor Exited with error code 255
Stderr: Enter passphrase for key '/home/nhaigh/.ssh/id_rsa': 
Permission denied (publickey,password).
[9] 09:59:37 [FAILURE] bioserver Exited with error code 255
Stderr: Enter passphrase for key '/home/nhaigh/.ssh/id_rsa': 
Permission denied (publickey,password).

I’ve confirmed that my SSH key and passphrase work on each of the machines so I have no idea how to get this working.