sshpass

sshpass is used to non interactively log in to remote SSH server and execute commands. It can use a password from a file, environment variable, or from a command-line argument.

To install sshpass on RHEL/CentOS, run

yum install sshpass

On Debian/Ubuntu

apt install sshpass

Example

boby@sok-01:~$ sshpass ssh -o StrictHostKeyChecking=no -p 3333 [email protected] "uptime"
 02:16:14 up 470 days, 10:41,  0 users,  load average: 0.07, 0.04, 0.04
boby@sok-01:~$ 

Take MySQL backup on a remote server

sshpass ssh -o StrictHostKeyChecking=no -p 3333 [email protected] "mysqldump serverok_wp > /root/serverok_wp.sql"

Command-line options for sshpass are

root@sok-01:~# sshpass
Usage: sshpass [-f|-d|-p|-e] [-hV] command parameters
   -f filename   Take password to use from file
   -d number     Use number as file descriptor for getting password
   -p password   Provide password as argument (security unwise)
   -e            Password is passed as env-var "SSHPASS"
   With no parameters - password will be taken from stdin

   -P prompt     Which string should sshpass search for to detect a password prompt
   -v            Be verbose about what you're doing
   -h            Show help (this screen)
   -V            Print version information
At most one of -f, -d, -p or -e should be used
root@sok-01:~#

To login to password using a password in the command line, use

sshpass -p PASSWORD_HERE ssh USER@SERVER_IP

To use a password from a file, use

echo 'PASSWORD_HERE' > pw_file
chmod 0400 pw_file
sshpass -f pw_file ssh USER@SERVER_IP

Using password-less authentication using an RSA key is much more secure. But sshpass can be used in places where you can’t use RSA key.

See SSH