SSH login without Password

Sometimes to automate management operations, you need to manage the authentication process. To avoid inserting the login information of Linux systems into DevOps or NetOps scripts you can generate a pair of authentication keys.

1. Generate a new pair of authentication keys:

techlab@Glitch01:~$ssh-keygen -t rsa
Generating public/private rsa key pair.
Enter file in which to save the key (/home/techlab/.ssh/id_rsa):
/home/techlab/.ssh/id_rsa already exists.
Overwrite (y/n)? y
Enter passphrase (empty for no passphrase):
Enter same passphrase again:
Your identification has been saved in /home/techlab/.ssh/id_rsa.
Your public key has been saved in /home/techlab/.ssh/id_rsa.pub.
The key fingerprint is:
SHA256:Q7KsCJ+cTCJhfiiu1yMKLbdz4a0q0D8Y17b09UslzM8 techlab@Glitch01
The key's randomart image is:
+---[RSA 2048]----+
| |
| |
|.. . . |
|o.. . + o |
|=+.. .o S + . |
|=O++o.+ .. = |
|+.XB.= o . .. E |
|+o=.B o . .. |
|o+o=.+ .. |
+----[SHA256]-----+

2. Copy the public key on the remote system:

cat .ssh/id_rsa.pub | ssh root@Glitch02 'cat >> .ssh/authorized_keys'

3. Test Login password-less:

ssh root@Glitch02

Bye

.glitchlist crew