Automated Certificate Management Environment (ACME) is a protocol that allows automated certificate requests, retrieval of certificates and certificate renewal. It was designed to enable easy deployment of X.509 certificates from Let's Encrypt.
debops.pki Ansible role provides support for the ACMEv2 protocol which
is used by default with the Let's Encrypt (there is a possibility to integrate
other similar services in the future). Interaction with the ACME Certificate
Authority is performed using the acme-tiny alternative client written in
Let's Encrypt rate limits¶
The Let's Encrypt ACME Certificate Authority has different rate limits related to the number of certificate requests and the number of domains permitted per certificate.
debops.pki role creates a cron entry for the pki-realm script
to be executed periodically for all realms. When a realm has the ACME
configuration active, it will check for validity of the certificate, and
about a month before the expiration date it will try to renew the certificate
Example: Certificate for apex domain and subdomains¶
The apex domain is the "root" level of your domain.
In this example a X.509 certificate for the apex domain
going to be issued.
example.com will be listed in the certificate
The certificate will also be valid for the subdomains
mail.example.com which are included in the
certificate as Subject Alternative Names.
pki_realms: - name: 'example.com' acme: True acme_subdomains: [ 'www', 'blog', 'mail' ] # acme_ca: 'le-staging-v2'
For testing it's strongly advised to uncomment
le-staging-v2 to use the staging environment of Let's Encrypt. It does not
create a trusted certificate and allows you to avoid problems with the rate
limits in the production environment. When you are sure that everything works
correctly, comment the staging environment out again to get yourself a valid
and trusted X.509 certificate.
Example: Certificate for subdomains excluding the apex domain¶
In the example we create a certificate for
Subject) and for
mon.example.com (certificate Subject Alternative
Names), which does not include the
example.com apex (root) domain.
pki_realms: - name: 'logs.example.com' acme: True acme_default_subdomains:  # Can also include different domains like 'mail.example.org' # in the same realm. acme_domains: [ 'mon.example.com' ] # acme_ca: 'le-staging-v2'
Again, for testing it's strongly advised to uncomment
acme_ca: le-staging-v2. See above for details.
ACME configuration variables¶
debops.pki role has several default variables which can be used to
control ACME support. The most important are:
- Boolean. When
True, support for ACME Certificate Authority will be configured for all PKI realms unless disabled on the realm level. By default the role checks if a public IP address is available and a default domain is configured, otherwise the support is disabled automatically.
- Boolean. Enable or disable installation of acme-tiny and configuration of
ACME support without enabling it for all realms. When this variable is set to
pki_acmeis set to
False, ACME support can be enabled independently in each PKI realm. By default, it is set to the same value as
- Name of the ACME Certificate Authority API endpoint to use. Dictionary with
endpoints is defined in the
pki_acme_ca_api_mapvariable. By default,
le-live-v2is used which points to the Let's Encrypt Live CA. For testing you can switch the default CA to
le-staging-v2which points to Let's Encrypt Staging CA.
- List of subdomains which will be added to the default ACME domain and all
other domains configured for ACME certificate by default, can be overridden by
item.acme_subdomainsparameter. By default, the
www.subdomain will be added to each domain configured in the realm. Remember that all subdomains need to be correctly configured in the DNS for the Certificate Authority to sign the request.
Each PKI realm configured in the
can have several parameters related to the ACME certificates:
- Name of the PKI realm. If it has at least one dot, the realm name will be treated as the apex (root) domain to configure for this realm.
- Boolean. Enable or disable ACME support per realm.
- List of additional apex (root) domains to add in ACME Certificate Signing Request. Each domain will have the default or custom subdomains added to it.
- List of subdomains that should be added to all of the ACME apex (root) domains.
If you want to create an ACME certificate only with the apex domain, you
might need to set this parameter to an empty list using
- List of subdomains added to each apex (root) domain configured in the ACME certificate. Overrides list of default ACME subdomains.
- List of Distinguished Name entries which define the ACME certificate Subject.