addjob

Password-free ssh authentication

Addjob uses SSH to connect to each host and submit jobs. For this to work properly, you must be able to ssh from your main machine to each host without entering a password.

This can be done securely through the ssh-keygen program, as follows:

Step 1: Generating an RSA key

On your main machine, run the ssh-keygen program as follows, accepting the defaults and leaving the passphrase empty:

[jared@dimebox:~]$ ssh-keygen -t rsa
Generating public/private rsa key pair.
Enter file in which to save the key (/home/jared/.ssh/id_rsa): [Just hit enter]
Enter passphrase (empty for no passphrase):  [Just hit enter]
Enter same passphrase again: [Just hit enter]
Your identification has been saved in /home/jared/.ssh/id_rsa.
Your public key has been saved in /home/jared/.ssh/id_rsa.pub.
The key fingerprint is:
...
$

Step 2: Distributing the key

Copy the entire contents of ~/.ssh/id_rsa.pub on your main machine into ~/.ssh/authorized_keys on every host machine. Note: if your home directory is shared by all the machines via NFS, you only need to do this once.

Step 3: Test it

Finally, make sure you can ssh from your main machine into the hosts without entering a password.

Addjob home page