Copying SSH Keys between different hosts
How to copy SSH keys between Linux hosts and from Windows to Linux.
Copy SSH key between Linux hosts
ssh-copy-id <user>@<ip-address>
# if target machine's hostname is in /etc/hosts
ssh-copy-id <user>@<hostname>
Copy SSH key between Windows and Linux
cat ~/.ssh/id_rsa.pub | ssh <user>@<hostname> 'cat >> .ssh/authorized_keys && echo "Key copied"'
The above command will fail if the .ssh folder does not already exist on the Linux host. Below is a more advanced command that will create the folder and give it correct permissions.
cat ~/.ssh/id_rsa.pub | ssh <user>@<hostname> 'umask 0077; mkdir -p .ssh; cat >> .ssh/authorized_keys && echo "Key copied"'
Next: GitHub Docs instructions for adding a GPG keys.