Simple password-less SSH login by pushing your key to remote server

ssh-copy-id <username>@<host>

Don’t forget to create your SSH key first.

Example:

root@odroidu2-1:~# ssh-copy-id pi@192.168.1.146
pi@192.168.1.146's password: (enter password)
Now try logging into the machine, with "ssh 'pi@192.168.1.146'", and check in:

  ~/.ssh/authorized_keys

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

root@odroidu2-1:~# ssh pi@192.168.1.146
...
pi@rpi-torrent ~ $

More info
Use ssh-copy-id when SSH port is not 22. (Custom port.)