SSH key setup for no-password login

ssh_key_setup.md

Don't use a password. Generate a passphraseless SSH key and push it to your VM/server.

If you already have an SSH key, you can skip this step. Just hit Enter for the key and both passphrases:

$ ssh-keygen -t rsa -b 2048
Generating public/private rsa key pair.
Enter file in which to save the key (/home/<username>/.ssh/id_rsa): 
Enter passphrase (empty for no passphrase): 
Enter same passphrase again: 
Your identification has been saved in /home/<username>/.ssh/id_rsa.
Your public key has been saved in /home/<username>/.ssh/id_rsa.pub.

Copy your keys to the target server:

$ ssh-copy-id id@server
id@server's password: 

Now try logging into the machine, with ssh 'id@server', and check in:

.ssh/authorized_keys

to make sure we haven’t added extra keys that you weren’t expecting.

Finally check logging in…

$ ssh id@server
id@server:~$ 

You may also want to look into using ssh-agent if you want to try keeping your keys protected with a passphrase.

Source: https://serverfault.com/questions/241588/how-to-automate-ssh-login-with-password