docker run -it --rm \
    -v $PWD/certbot/etc-letsencrypt/:/etc/letsencrypt/ \
    -v $PWD/certbot/var-log-letsencrypt/:/var/log/letsencrypt/ \
    -v $PWD/certbot/var-lib-letsencrypt/:/var/lib/letsencrypt \
    certbot/certbot certonly -d '*.big.io' -d 'big.io' --preferred-challenges=dns --manual