Cheatsheet based upon https://www.raspberrypi.org/documentation/remote-access/ssh/passwordless.md
On the Mac create a key (once) with a passcode
Add the key to your Mac keychain
ssh-add -K ~/.ssh/id_rsa
Optionally create a file
~/.ssh/config with these contents which contains the UseKeychain yes line which tells OSX to look at the keychain for the passphrase.
Host * UseKeychain yes AddKeysToAgent yes IdentityFile ~/.ssh/id_rsa
Then copy your key to your Raspberry PI
SSH to the PI
Next edit your
/etc/ssh/sshd_config to turn off plain text password authentication and restart
sudo sed -i "s/#PasswordAuthentication yes/PasswordAuthentication no/g" /etc/ssh/sshd_config sudo /etc/init.d/ssh restart
Now you can SSH without a password and without getting pestered that the default password hasn’t been changed.