post_install() {
	echo '==> To use this package, create a credential file in this format:'
	echo '==>	dns_vultr_token = aabbccddeeff112233445566778899'
	echo '==> Once that is done, use the following certbot options:'
	echo '==>	--authenticator dns-vultr'
	echo '==>	--dns-vultr-credentials /path/to/credential/file.ini'
	echo '==>	--preferred-challenges dns-01'
}

post_upgrade() {
	if [[ "$2" =~ ^20190506-[0-9]+$ ]]; then
		echo '==> WARNING: THIS PACKAGE NOW USES A CREDENTIAL FILE'
		post_install
	fi
}

post_remove() {
	echo "==> Don't forget to remove the package from your certbot command"
}