• Create the boy system account.
  • Create an ssh-key: 
    ssh-keygen -t ed25519
  • Install ?only
  • Configure ‘only’ for boy

Install ‘only’

cd /opt || cat >&2
darcs clone http://at.magma-soft.at/darcs/only
cp only /usr/local/bin
chmod +x /usr/local/bin/only

Configure ‘only’ for boy

cd ~boy || cat >&
cp /opt/only/.onlyrc .
sed -i 's/^#show_allowed$/show_allowed/' .onlyrc
sed -i 's/^#show_denied$/show_denied/' .onlyrc