ssh-copy-idで公開鍵を渡す ref: http://qiita.com/kentarosasaki/items/aa319e735a0b9660f1f0

.sshがすでに存在するなら

cat ~/.ssh/id_rsa.pub | ssh ${USER}@${target_host} "cat >> ~/.ssh/authorized_keys"

file0.txt

ssh-copy-id ${USER}@${target_host}

file1.txt

ssh-copy-id -i ${identity_file} ${USER}@${target_host}

file2.txt

cat ~/.ssh/id_rsa.pub | ssh ${USER}@${target_host} "mkdir -p ~/.ssh; cat >> ~/.ssh/authorized_keys"

id_rsa.pubを渡す場合

ssh-copy-id ${USER}@${target_host}

もし初回のログインのときなら

cat ~/.ssh/id_rsa.pub | ssh ${USER}@${target_host} "mkdir ~/.ssh; cat >> ~/.ssh/authorized_keys"