Create user on remote host

#!/bin/bash
HOST=$1
USER=$2
SSH_PUBKEY_FILE=$3

if [ -z "$HOST" -o -z "$USER" -o -z "$SSH_PUBKEY_FILE" ]
then
        echo "Usage: $0 <host> <user> <ssh_authorized_keys_file>"
        exit 1
fi

USER_ENTRY="`ssh "${HOST}" getent passwd "${USER}"`"
if [ ! -z "$USER_ENTRY" ]
then
        echo "User ${USER} already exists on ${HOST}"
        echo "${USER_ENTRY}"
        exit 1
fi

ssh "root@$HOST" "
useradd -m -s /bin/bash -U ${USER}
su ${USER} -c 'cd;mkdir .ssh;chmod 700 .ssh'
"

scp "$3" "root@$HOST":/home/"$USER"/.ssh/authorized_keys

ssh "root@$HOST" "
chown ${USER}:${USER} -R /home/"${USER}"/.ssh
chmod 600 /home/"${USER}"/.ssh/authorized_keys
"