Bash script to disable root login

Question

I'm trying to automate as much as possible in the deployment of servers, the overall goal is to login as a user, upload a bashscript and have it configure my server how I need it configured.

To start I'm trying to disable root login, I know I have to edit /etc/ssh/sshd_config to PermitRootLogin no

I was wondering if there was a way to do this via a bash script?

Answer 1

If you want to just append your text to the sshd_config file, you could use printf like this:

printf '\n%s\n' 'PermitRootLogin no' >>/etc/ssh/sshd_config

or if you want to change a file that already have a value set, but you want to set it to no, could use sed like this:

sed -i '/^PermitRootLogin[ \t]\+\w\+$/{ s//PermitRootLogin no/g; }' /etc/ssh/sshd_config