certbot-he-hook.sh

#!/bin/bash

#
# Certbot hook for Hurricane Electric DNS service
#
# Usage:
#
# Renew all certificates:
# HE_SESSID=<session_id> certbot renew \
#   --preferred-challenges dns \
#   --manual-auth-hook /path/to/certbot-he-hook.sh  \
#   --manual-public-ip-logging-ok
#
# Create a new certificate:
# HE_SESSID=<session_id> certbot certonly \
#   --preferred-challenges dns \
#   --email your@email.com \
#   --manual \
#   --manual-auth-hook /path/to/certbot-he-hook.sh  \
#   --manual-public-ip-logging-ok \
#   --domain <requested.domain.com>
#

ZONENAME_REGEX=$(echo $CERTBOT_DOMAIN | awk -F '.' '{ print $(NF-1) "\\." $NF }')
HE_ZONEID=$(curl --stderr - --cookie CGISESSID=$HE_SESSID https://dns.he.net/index.cgi \
  | grep -Eo "delete_dom.*name=\"$ZONENAME_REGEX\" value=\"[0-9]+" | grep -Eo "[0-9]+$")

curl --stderr - -o /dev/null --cookie CGISESSID=$HE_SESSID https://dns.he.net/index.cgi \
  -d "account=&menu=edit_zone&Type=TXT&hosted_dns_zoneid=$HE_ZONEID&hosted_dns_recordid=&hosted_dns_editzone=1&Priority=&Name=_acme-challenge.$CERTBOT_DOMAIN&Content=$CERTBOT_VALIDATION&TTL=300&hosted_dns_editrecord=Submit"

An improved version is here: https://github.com/angel333/certbot-he-hook