Ansible Role: ACME (DNS challenge)

This Ansible role generates a certificate from LetsEncrypt using the DNS challenge method. Initially it will only support domains that are hosted using either Cloudflare OR AWS Route53, but it should be relatively straight-forward to add support for other DNS providers in the future.

The motivation for creating this role was that I needed a simple and straight-forward way to generate LetsEncrypt certificates, one that could also work independently of any external services (such as Traefik or Certbot).

By not having this process tied to any particular service, I can easily integrate it with everything else that I already use within my environment - namely Consul, Nomad and Vault.

Requirements

• Linux
• openssl

Usage

There are only a few key variables that this role requires for generating the LetsEncrypt certificates:

• 1) DNS provider variables; and
• 2) LetsEncrypt certificate variables

---

1) DNS provider variables

To use one of the following DNS providers, configure the relevant role variables:

• a) AWS Route53: variable prefix = acmedns_r53_
• b) Cloudflare: variable prefix = acmedns_cf_

a) AWS Route53

acmedns_provider: r53
acmedns_r53_zone: Z123EXAMPLE      # Hosted-zone ID to use when generating the certificate
acmedns_r53_access_key: ACCESSKEY  # Access key of an account with permission to add records to the hosted zone
acmedns_r53_secret_key: SECRETKEY  # Secret key of an account with permission to add records to the hosted zone

b) Cloudflare

acmedns_provider: cf
acmedns_cf_zone: example.com        # Cloudflare DNS zone to use when generating the certificate
acmedns_cf_email: [email protected]  # Email address of your Cloudflare account
acmedns_cf_token: EXAMPLETOKEN      # Zone-specific API Token with 'Zone:DNS:Edit' and 'Zone:Zone:Read' permissions

---

2) LetsEncrypt certificate variables

To keep configuration simple, you only need to specify the following variables for the to-be-generated certificate:

acmedns_le_cn: test.example.com     # Common Name to use for the generated certificate
acmedns_le_email: [email protected]  # Email address of your LetsEncrypt account (created if non-existent)
acmedns_le_sans:                    # (optional) List of Subject Alternative Names for the generated certificate
  - 'another.test.example.com'
  - '*.test.example.com'

---

Other variables

This role will look for a LetsEncrypt account key named letsencrypt.pem within the ~/.local/share/letsencrypt directory. This is also where all certificates will be generated and saved.

You can specify the path to your LetsEncrypt account key and change the directory where certificates are saved by modifying the following variables:

acmedns_le_dir: /etc/acme                  # default: ~/.local/share/letsencrypt
acmedns_le_accountkey: /etc/acme/acme.key  # default: ~/.local/share/letsencrypt/letsencrypt.pem

Example Playbook

AWS Route53:

---
- hosts: localhost
  roles:
    - role: snoord.acmedns
      vars:
        # LetsEncrypt
        acmedns_le_email: [email protected]
        acmedns_le_cn: example.com
        acmedns_le_sans:
          - '*.example.com'
        # AWS Route53
        acmedns_provider: r53
        acmedns_r53_zone: Z123EXAMPLE
        acmedns_r53_access_key: ACCESSKEY
        acmedns_r53_secret_key: SECRETKEY
...

Cloudflare:

---
- hosts: localhost
  roles:
    - role: snoord.acmedns
      vars:
        # LetsEncrypt
        acmedns_le_email: [email protected]
        acmedns_le_cn: example.com
        acmedns_le_sans:
          - '*.example.com'
        # Cloudflare
        acmedns_provider: cf
        acmedns_cf_zone: example.com
        acmedns_cf_email: [email protected]
        acmedns_cf_token: EXAMPLETOKEN
...

License

MIT / BSD

Author Information

Created by Samuel Noordhuis in 2020. Inspired heavily by the Ansible roles and writings of Jeff Geerling.

If you see any errors or think this role could be improved in some way, you are welcome to open an issue/feature request or create a pull request :)