useradd -m -s /bin/bash ubuntu
usermod -aG sudo ubuntu
echo 'ubuntu ALL=(ALL) NOPASSWD:ALL' > /etc/sudoers.d/ubuntu
chmod 440 /etc/sudoers.d/ubuntu

# Disable root login
sed -i 's/^PermitRootLogin yes/PermitRootLogin no/' /etc/ssh/sshd_config
systemctl reload ssh

# Set default user to ubuntu
sed -i '/default_user:/,/lock_passwd:/ s/^\([[:space:]]*name:[[:space:]]*\)root$/\1ubuntu/' /etc/cloud/cloud.cfg
cloud-init clean