proper way to sudo over ssh

Question

I have a script which runs another script via SSH on a remote server using sudo. However, when I type the password, it shows up on the terminal. (Otherwise it works fine)

ssh user@server "sudo script"

What's the proper way to do this so I can type the password for sudo over SSH without the password appearing as I type?

Answer 1

Depending on your usage, I had success with the following:

ssh root@server "script"

This will prompt for the root password and then execute the command correctly.

Answer 2

The best way is ssh -t user@server "sudo <scriptname>", for example ssh -t user@server "sudo reboot". It will prompt for password for user first and then root(since we are running the script or command with root privilege.

I hope it helped and cleared your doubt.

Answer 3

echo $VAR_REMOTEROOTPASS | ssh -tt -i $PATH_TO_KEY/id_mykey $VAR_REMOTEUSER@$varRemoteHost 
echo \"$varCommand\" | sudo bash

Answer 4

I was able to fully automate it with the following command:

echo pass | ssh -tt user@server "sudo script"

Advantages:

• no password prompt
• won't show password in remote machine bash history

Regarding security: as Kurt said, running this command will show your password on your local bash history, and it's better to save the password in a different file or save the all command in a .sh file and execute it. NOTE: The file need to have the correct permissions so that only the allowed users can access it.

Answer 5

Another way is to use the -t switch to ssh:

ssh -t user@server "sudo script"

See man ssh:

 -t      Force pseudo-tty allocation.  This can be used to execute arbi-
         trary 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.

Answer 6

I faced a problem,

user1@server1$ ssh -q user1@server2 sudo -u user2 rm -f /some/file/location.txt

Output:
sudo: no tty present and no askpass program specified

Then I tried with

#1
vim /etc/sudoers
Defaults:user1    !requiretty

didn't work

#2
user1   ALL=(user2)         NOPASSWD: ALL

that worked properly!