In addition to ssh-copy-id that is already mentioned is ssh-import-id which copies a key from launchpad.net or github.com.
It is available in ubuntu and maybe elsewhere by default.
It is roughly equivalent to curl -s https://api.github.com/users/$USER/keys | jq -r .[].key >> ~/.ssh/authorized_keys assuming your username is the same on github as it is on the linux system.
In addition to ssh-copy-id that is already mentioned is ssh-import-id which copies a key from launchpad.net or github.com.
It is available in ubuntu and maybe elsewhere by default.
It is roughly equivalent to
curl -s https://api.github.com/users/$USER/keys | jq -r .[].key >> ~/.ssh/authorized_keysassuming your username is the same on github as it is on the linux system.Does that mean that Github ir Launchpad gets access to the files on your computer?
No. The ssh-import-id runs on your computer and calls remote API and writes the file on your computer.