Let's Encrypt for Wildcard Domains with Heroku and Cloudflare

cert.sh

#!/bin/sh
set -e

# NEEDS THE FOLLOWING VARS IN ENV:
# DOMAIN
# CLOUDFLARE_EMAIL
# CLOUDFLARE_API_KEY
# HEROKU_APP

# Download dependencies
git clone https://github.com/Neilpang/acme.sh.git
cd ./acme.sh

# Force ensures it doesnt fail because of lack of cron
./acme.sh --install --force

# Map to environment variables that the ACME script requires
export CF_Email=$CLOUDFLARE_EMAIL
export CF_Key=$CLOUDFLARE_API_KEY

# Generate wildcard certificate (this will take approx 130s)
~/.acme.sh/acme.sh  --issue -d $DOMAIN  -d "*.$DOMAIN"  --dns dns_cf

# Update the certificate in the live app
heroku certs:update "~/.acme.sh/$DOMAIN/fullchain.cer" "~/.acme.sh/$DOMAIN/$DOMAIN.key" --confirm $HEROKU_APP --app $HEROKU_APP