Ansible Role: Certbot (for Let's Encrypt)

Installs and configures Certbot (for Let's Encrypt).

Requirements

If installing from source, Git is required. You can install Git using the geerlingguy.git role.

Generally, installing from source (see section Source Installation from Git) leads to a better experience using Certbot and Let's Encrypt, especially if you're using an older OS release.

Role Variables

certbot_install_method: package

Controls how Certbot is installed. Available options are 'package', 'snap', and 'source'.

certbot_auto_renew: true
certbot_auto_renew_user: "{{ ansible_user | default(lookup('env', 'USER')) }}"
certbot_auto_renew_hour: "3"
certbot_auto_renew_minute: "30"
certbot_auto_renew_options: "--quiet"

By default, this role configures a cron job to run under the provided user account at the given hour and minute, every day. The defaults run certbot renew (or certbot-auto renew) via cron every day at 03:30:00 by the user you use in your Ansible playbook. It's preferred that you set a custom user/hour/minute so the renewal is during a low-traffic period and done by a non-root user account.

Automatic Certificate Generation

Currently the standalone, webroot and dns methods are supported for generating new certificates using this role.

For a complete example: see the fully functional test playbook in molecule/default/playbook-standalone-nginx-aws.yml.

certbot_create_if_missing: false

Set certbot_create_if_missing to yes or True to let this role generate certs.

certbot_create_method: standalone

Set the method used for generating certs with the certbot_create_method variable — current allowed values are: standalone, webroot, or dns.

certbot_testmode: false

Enable test mode to only run a test request without actually creating certificates.

certbot_hsts: false

Enable (HTTP Strict Transport Security) for the certificate generation.

certbot_admin_email: email@example.com

The email address used to agree to Let's Encrypt's TOS and subscribe to cert-related notifications. This should be customized and set to an email address that you or your organization regularly monitors.

certbot_certs: []
  # - email: janedoe@example.com
  #   webroot: "/var/www/html"
  #   domains:
  #     - example1.com
  #     - example2.com
  # - domains:
  #     - example3.com

A list of domains (and other data) for which certs should be generated. You can add an email key to any list item to override the certbot_admin_email. When using the webroot creation method, a webroot item has to be provided, specifying which directory to use for the authentication. Make sure your webserver correctly delivers contents from this directory.

certbot_create_command: "{{ certbot_script }} certonly --standalone --noninteractive --agree-tos --email {{ cert_item.email | default(certbot_admin_email) }} -d {{ cert_item.domains | join(',') }}"

The certbot_create_command defines the command used to generate the cert. See the full default command inside defaults/main.yml for a full example—and you can easily add in extra arguments that are not in the default command with the certbot_create_extra_args variable.

Standalone Certificate Generation

certbot_create_standalone_stop_services:
  - nginx

Services that should be stopped while certbot runs it's own standalone server on ports 80 and 443. If you're running Apache, set this to apache2 (Ubuntu), or httpd (RHEL), or if you have Nginx on port 443 and something else on port 80 (e.g. Varnish, a Java app, or something else), add it to the list so it is stopped when the certificate is generated.

These services will only be stopped the first time a new cert is generated.

Webroot Certificate Generation

When using the webroot creation method, a webroot item has to be provided for every certbot_certs item, specifying which directory to use for the authentication. Also, make sure your webserver correctly delivers contents from this directory.

DNS Certficate Generation

When using the dns creation method, you must specify certbot_dns_plugin to specify which DNS plugin should be used:

certbot_dns_plugin: 'route53'

It's important to note that most of the DNS plugins require additional configuration, which must be configured elsewhere in your playbook. For example, some DNS plugins (e.g. AWS Route53), require environment variables to be set. This can be achieved with the environment module:

environment:
  AWS_ACCESS_KEY_ID: "{{ aws_access_key }}"
  AWS_SECRET_ACCESS_KEY: "{{ aws_secret_key }}"
  AWS_DEFAULT_REGION: "us-east-1"

Others (e.g. Digital Ocean) require you to pass an extra argument with the path to a configuration file.

certbot_create_extra_args: "--dns-digitalocean-credentials=/tmp/digitalocean_token.ini"

This approach of using certbot_create_extra_args also allows you to configure other DNS options, for example --dns-digitalocean-propagation-seconds=30 to set the time to wait for DNS propagation.

Snap Installation

Beginning in December 2020, the Certbot maintainers decided to recommend installing Certbot from Snap rather than maintain scripts like certbot-auto.

Setting certbot_install_method: snap configures this role to install Certbot via Snap.

This install method is currently experimental and may or may not work across all Linux distributions.

Source Installation from Git

You can install Certbot from it's Git source repository if desired with certbot_install_method: source. This might be useful in several cases, but especially when older distributions don't have Certbot packages available (e.g. CentOS < 7, Ubuntu < 16.10 and Debian < 8).

certbot_repo: https://github.com/certbot/certbot.git
certbot_version: master
certbot_keep_updated: true

Certbot Git repository options. If installing from source, the configured certbot_repo is cloned, respecting the certbot_version setting. If certbot_keep_updated is set to yes, the repository is updated every time this role runs.

certbot_dir: /opt/certbot

The directory inside which Certbot will be cloned.

Wildcard Certificates

Let's Encrypt supports generating wildcard certificates using the DNS method (certbot_create_method: dns) only.

Dependencies

None.

Example Playbook

- hosts: servers

  vars:
    certbot_auto_renew_user: your_username_here
    certbot_auto_renew_minute: "20"
    certbot_auto_renew_hour: "5"

  roles:
    - geerlingguy.certbot

See other examples in the tests/ directory.

Manually creating certificates with certbot

Note: You can have this role automatically generate certificates; see the "Automatic Certificate Generation" documentation above.

You can manually create certificates using the certbot (or certbot-auto) script (use letsencrypt on Ubuntu 16.04, or use /opt/certbot/certbot-auto if installing from source/Git. Here are some example commands to configure certificates with Certbot:

# Automatically add certs for all Apache virtualhosts (use with caution!).
certbot --apache

# Generate certs, but don't modify Apache configuration (safer).
certbot --apache certonly

If you want to fully automate the process of adding a new certificate, but don't want to use this role's built in functionality, you can do so using the command line options to register, accept the terms of service, and then generate a cert using the standalone server:

1. Make sure any services listening on ports 80 and 443 (Apache, Nginx, Varnish, etc.) are stopped.
2. Register with something like certbot register --agree-tos --email [your-email@example.com] - Note: You won't need to do this step in the future, when generating additional certs on the same server.
3. Generate a cert for a domain whose DNS points to this server: certbot certonly --noninteractive --standalone -d example.com -d www.example.com
4. Re-start whatever was listening on ports 80 and 443 before.
5. Update your webserver's virtualhost TLS configuration to point at the new certificate (fullchain.pem) and private key (privkey.pem) Certbot just generated for the domain you passed in the certbot command.
6. Reload or restart your webserver so it uses the new HTTPS virtualhost configuration.

Certbot certificate auto-renewal

By default, this role adds a cron job that will renew all installed certificates once per day at the hour and minute of your choosing.

You can test the auto-renewal (without actually renewing the cert) with the command:

/opt/certbot/certbot-auto renew --dry-run

See full documentation and options on the Certbot website.

License

MIT / BSD

Author Information

This role was created in 2016 by Jeff Geerling, author of Ansible for DevOps.