How to execute commands on Multiple Remote Server - pssh

Executable Commands on Multiple Remote Linux Servers Using Single Terminal &ndash pssh

This article gives information about the installation of pssh. PSSH tool comes in handy, python based application that allow us to execute commands on multiple hosts in parallel at the same time.

Some of the PSSH tools

pscp &ndash Copy/Transfer Files Two or More Remote Linux Servers
pslurp &ndash copies files from multiple remote hosts to a central host in parallel.
prsync &ndash is a program for efficiently copying files to multiple hosts in parallel.
pssh &ndash is a program for running ssh in parallel on a multiple remote hosts.
pscp &ndash is a program for copying files in parallel to a number of hosts.
pnuke &ndash kills processes on multiple remote hosts in parallel.

It can be work with large collections of nodes on a network.

To Install PSSH or Parallel SSH on Linux

Use pip command which is a small program to install and manage the Python software packages index.c. Before installing the packages, update your repositories.

root@linuxhelp:~# apt-get update 
Get:1 http://security.ubuntu.com wily-security InRelease [65.9 kB]
Hit http://in.archive.ubuntu.com wily InRelease          
Get:2 http://in.archive.ubuntu.com wily-updates InRelease [65.9 kB]            
Get:3 http://in.archive.ubuntu.com wily-backports InRelease [65.9 kB]          
Get:4 http://security.ubuntu.com wily-security/main Sources [48.9 kB]
.
.
.
Get:50 http://in.archive.ubuntu.com wily-backports/restricted Translation-en [28 B]
Get:51 http://in.archive.ubuntu.com wily-backports/universe Translation-en [1,390 B]
Fetched 1,789 kB in 1min 4s (27.8 kB/s)                                        
Reading package lists... Done

Now install the python-pip package.

root@linuxhelp:~# apt-get install python-pip -y
Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following packages were automatically installed and are no longer required:
  libavahi-client-dev libavahi-common-dev libavahi-compat-libdnssd1
.
.
.
Setting up python-requests (2.7.0-3) ...
Setting up python-setuptools (18.4-1) ...
Setting up python-pip (1.5.6-7ubuntu1.2) ...
Setting up python-wheel (0.26.0-1) ...

Then install PSSH using pip command.


root@linuxhelp:~# pip install pssh
Downloading/unpacking pssh
  Downloading pssh-2.3.1.tar.gz
  Running setup.py (path:/tmp/pip-build-lmMWO5/pssh/setup.py) egg_info for package pssh
    
Installing collected packages: pssh
  Running setup.py install for pssh
    changing mode of build/scripts-2.7/pssh from 644 to 755
    changing mode of build/scripts-2.7/pnuke from 644 to 755
    changing mode of build/scripts-2.7/prsync from 644 to 755
    changing mode of build/scripts-2.7/pslurp from 644 to 755
    changing mode of build/scripts-2.7/pscp from 644 to 755
    changing mode of build/scripts-2.7/pssh-askpass from 644 to 755
    
    changing mode of /usr/local/bin/pssh-askpass to 755
    changing mode of /usr/local/bin/pnuke to 755
    changing mode of /usr/local/bin/pssh to 755
    changing mode of /usr/local/bin/pscp to 755
    changing mode of /usr/local/bin/pslurp to 755
    changing mode of /usr/local/bin/prsync to 755
Successfully installed pssh
Cleaning up...

How to use pssh

Create a host “ node.txt” file with the number of hosts along with IP address and port number which is used to connect to remote systems using pssh

root@linuxhelp:~# vim node.txt

Now the node.txt file is created. Add the Following entries in the file.

Entry:
192.168.5.88:22

To execute single command on multiple server using pssh

There are many options to execute single command on multiple server using pssh. Some of them are,

To include a default username on all hosts that do not define a specific user, use the -l username or &ndash user username option.
We can also display standard output and standard error as each host completes. By using the -i or &ndash inline option.
To ask for a password and send to ssh, use the -A option.
To read hosts file, include the -h host_file-name or &ndash hosts host_file_name option.
We may wish to make connections time out after the given number of seconds by including the -t number_of_seconds option.
To save standard output to a given directory, you can use the -o /directory/path option.

Some examples and usage of pssh commands

Execute the ifconfig command by using PSSH over remote machines.

root@linuxhelp:~# pssh -h node.txt -l root -A -i " ifconfig" 
Warning: do not enter your password if anyone else has superuser
privileges or access to your account.
Password: 
[1] 09:40:05 [SUCCESS] 192.168.5.88:22
eno16777736: flags=4163< UP,BROADCAST,RUNNING,MULTICAST>   mtu 1500
        inet 192.168.5.88  netmask 255.255.255.0  broadcast 192.168.5.255
        inet6 fe80::20c:29ff:fe83:a038  prefixlen 64  scopeid 0x20
        ether 00:0c:29:83:a0:38  txqueuelen 1000  (Ethernet)
        RX packets 1926  bytes 171341 (167.3 KiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 157  bytes 20285 (19.8 KiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

lo: flags=73< UP,LOOPBACK,RUNNING>   mtu 65536
        inet 127.0.0.1  netmask 255.0.0.0
        inet6 ::1  prefixlen 128  scopeid 0x10
        loop  txqueuelen 0  (Local Loopback)
        RX packets 10  bytes 870 (870.0 B)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 10  bytes 870 (870.0 B)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

Run the below command to check the kernel version on remote machine.

root@linuxhelp:~# pssh -h node.txt -l root -A -i " uname -r" 
Warning: do not enter your password if anyone else has superuser
privileges or access to your account.
Password: 
[1] 09:51:06 [SUCCESS] 192.168.5.88:22
3.10.0-123.el7.x86_64

pssh help

root@linuxhelp:~# pssh --help
Usage: pssh [OPTIONS] command [...]

Options:
  --version             show program' s version number and exit
  --help                show this help message and exit
  -h HOST_FILE, --hosts=HOST_FILE
                        hosts file (each line " [user@]host[:port]" )
  -H HOST_STRING, --host=HOST_STRING
                        additional host entries (" [user@]host[:port]" )
  -l USER, --user=USER  username (OPTIONAL)
  -p PAR, --par=PAR     max number of parallel threads (OPTIONAL)
  -o OUTDIR, --outdir=OUTDIR
                        output directory for stdout files (OPTIONAL)
  -e ERRDIR, --errdir=ERRDIR
                        output directory for stderr files (OPTIONAL)
  -t TIMEOUT, --timeout=TIMEOUT
                        timeout (secs) (0 = no timeout) per host (OPTIONAL)
  -O OPTION, --option=OPTION
                        SSH option (OPTIONAL)
  -v, --verbose         turn on warning and diagnostic messages (OPTIONAL)
  -A, --askpass         Ask for a password (OPTIONAL)
  -x ARGS, --extra-args=ARGS
                        Extra command-line arguments, with processing for
                        spaces, quotes, and backslashes
  -X ARG, --extra-arg=ARG
                        Extra command-line argument
  -i, --inline          inline aggregated output and error for each server
  --inline-stdout       inline standard output for each server
  -I, --send-input      read from standard input and send as input to ssh
  -P, --print           print output as we get it

Tag : PSSH

FAQ

I see there is a " -l " option to pass userid. How do I pass password of the host pro-grammatically. That is, the password must be sent from a script based on password entered in some web pag

Check out the -A or – -askpass flag, it is used to prompt for a password and pass it to ssh.

I want to run multiple commands on servers instead of single command or is there any way that pssh read commands from a file one by one and print the output on terminal ?

Yes, you specify the commands in a shell script, eg. commands.sh and make it executable. Then use the -I flag to run commands from it

is it possible to execute a command on different server using root user but every server has got a different root password and I don’t want install a key on every servers?

That would be complicated, i suppose the easiest way to use Pssh is to install a key on every servers. I can not certainly tell if you can use it with different root passwords on the differen

is there any command like MPSSH?if there what is difference

yeap, there is a command called MPSSH the difference is PSSH is for execute commands on multiple servers in parallel at the same time. MPSSH – Mass Parallel Secure Shell executes multiple

is this available for windows ?

yes , there is a tool which is like PSSH called "IdeaConnect parallelSSH"