How could I shutdown a remote host, in my network thru ssh, with a local host?

ssh shutdown openssh wakeonlan

30,382

For the following I am assuming that the user you are going to use in remote-host is the same you use in local-host.

In order to do what you want, you have to first authorize your local-host to connect to you remote-host with no password. To do that you have to (as described here):

Install ssh:
```
sudo apt-get install ssh
```

Create public and private keys using ssh-key-gen on local-host by entering this command in your localhost:

ssh-keygen

You should save the generated key in:

/home/yourusername/.ssh/id_rsa

Press enter twice to leave the passphrase empty.

Your identification has been saved in /home/yourusername/.ssh/id_rsa.
Your public key has been saved in /home/yourusername/.ssh/id_rsa.pub.
The key fingerprint is:
XX:XX:XX:xX:XX:xX:XX:XX:XX:XX:XX:XX:XX:XX yourusername@local-host

Copy the public key to the remote-host using ssh-copy-id:
```
yourusername@local-host$ ssh-copy-id -i ~/.ssh/id_rsa.pub remote-host
yourusername@remote-host's password:

Now try logging into the machine, with:

ssh remote-host
```
and check in .ssh/authorized_keys to make sure we haven't added extra keys that you weren't expecting.

Note: ssh-copy-id appends the keys to the remote-host’s /home/yourusername/.ssh/authorized_key.
Login to remote-host without entering the password:
```
ssh remote-host
yourusername@remote-host:~$
```
Access to remote-host with no password. Success!

Now you have to be able to execute sudo shutdown -P 0 with no password. You can do that by modifying /etc/sudoers on remote-host with visudo. That way, user yourusername can execute the shutdown command with no password asked.

Login to the remote-host:
```
ssh remote.host
```
Run:
```
sudo visudo
```
By running visudo, you edit /etc/sudoers in a safe manner.

Add this line to the file:

yourusername ALL = NOPASSWD: /sbin/shutdown

After doing that, get back to your local-host, create a new empty file and paste this line, modifying the remote-host's name:
```
ssh remote.host sudo shutdown -P 0
```
Save and close the file, right-click on it to go to its Properties → Permissions, and tick Execute this file as a program.

Script done!

30,382

DeLiK

Updated on September 18, 2022

Comments

DeLiK over 1 year
The question is simple.
What would be the script I would have to use to shut down a computer in my network thru ssh.

Normaly i would go to command line and:
```
ssh desktop

delik@desktop's password: 

delik@desktop:~$ sudo shutdown -P 0
```
To power on I created a file and wrote:
```
wakeonlan xx:xx:xx:xx:xx:xx
```
And gave it the executable bit

That way to power on it requires only a double click. Would i be capable of doing the same to shutdown?
DeLiK over 11 years

Would you improve your answer with some examples on how to do that exactly?
mene over 11 years

You can check this out for the login part: thegeekstuff.com/2008/11/… You can use usermod -s /home/username/myscript.sh username to change the default shell. The script should be something like #!/bin/bash shutdown -P now
DeLiK over 11 years

You are right, the ssh login problem is solved, but now I have to build a script with a "pause" so it waits for ssh desktop to happen succesfully. And after that i have another problem how to give the command in sudo and enter the password?
DeLiK over 11 years

I manage to do that. Now I can shut down with sudo shutdown -P 0 with no password
Peachy over 11 years

@mene, would you consider editing your answer to add the details you posted as comments? That way, your answer will be clear, complete and useful to other users.
Kevin Vella about 3 years

Just what I needed, thanks a lot!