Dyn API hook for Dehydrated

host.rb is a hook, driven by hook.sh, for Dehydrated to get certificates from Let's Encrypt using the dns-01 challenge-response method, for Dyn Managed DNS.

It uses the official dyn-rb gem to access the Dyn REST API, configured using Dehydrated's config file.

The dns-01 challenge-response is useful because it lets you get all of your certs from one ACME client, to save you littering clients on every host in your infrastructure that needs a cert. That's especially useful for hosts where you can't install and operate a client, like routers, where certificates can still be installed.

It's a much more sensible method than the HTTP challenge-response method for that reason.

Basic Usage

0. Clone Dehydrated
1. Clone this hook
2. Configure Dehydrated (config file) to tell it where the hook is, provide your Dyn account details, and provide a path to hook.rb for hook.sh to call
3. Setup your domains.txt
4. Run Dehydrated and get certificates

Example Dehydrated Configuration

Here's an example config for Dehydrated. Set it up to your own liking.

CA="https://acme-staging.api.letsencrypt.org/directory"
HOOK=/path/to/hook.sh
CHALLENGETYPE="dns-01"
CERTDIR="${BASEDIR}/certs"
ACCOUNTDIR="${BASEDIR}/accounts"
CONTACT_EMAIL="your.email@address.com"
# config for hook.sh and host.rb
export DYN_ACCOUNTNAME="yourdynaccountname"
export DYN_USERNAME="yourdynapiusername"
export DYN_PASSWORD="yourdynapipassword"
export HOST_RB=/path/to/host.rb

Notes

• In the config above, I'm using the staging Let's Encrypt directory. Please test against that yourself before making live requests.
• It doesn't handle Dehydrated's calls to unchanged_cert or deploy_cert in hook.sh. You might want to fill those in to do something useful on your setup, after Dehydrated gets your certs.
• If it wasn't obvious, host.rb is Ruby code, so you'll need a functioning Ruby and the dyn-rb gem for the hook to execute properly.
• The 5 second sleeps in host.rb might not be necessary, they just helped me debug the order of interaction between Dehydrated and how it calls a configured hook.