Here is the full solution, thanks to michaelmior for his help, it got me half way.
Run this command to generate keys:
You'll get this output:
Generating public/private rsa key pair.
Enter file in which to save the key (/home/user1/.ssh/id_rsa):
Created directory ‘/home/user1/.ssh’.
Enter passphrase (empty for no passphrase): (just hit enter, no need for a password)
Enter same passphrase again: (same thing, hit enter again)
Your identification has been saved in /home/user1/.ssh/id_rsa.
Your public key has been saved in /home/user1/.ssh/id_rsa.pub.
The key fingerprint is:
Add the public key to your
chown the files to the same user as your webserver (in my case apache)
chmod the files to 600:
chmod 600 id_rsa*
This should now work.
However, my installation kept hanging, a quick look at the httpd error_log file show me:
PHP Fatal error: Allowed memory size of 33554432 bytes exhausted (tried to allocate 2966269 bytes) in /var/www/sites/....
Adding this code to the Wordpress
wp-config.php file to temporally increase the amount of memory available: