permit multiple DKIM selectors

README.md

@@ -19,6 +19,7 @@ on a single host.
 * `mailfruit_admin_email` - *required*
 * `mailfruit_certbot_authenticator` - _optional_, default: `standalone`
 * `mailfruit_trees_git_ref` - _optional_, default: `master`
+* `mailfruit_dkim_selector` - _optional_, default: `mail`. Set this to something unique per-server, unless you syncronize your DKIM keys another way.
 
 ## Example Playbook
 

templates/opendkim.conf.j2

@@ -11,7 +11,7 @@ InternalHosts           csl:127.0.0.1/24,localhost
 Domain                  csl:{% for domain in mailfruit_mail_domains %}{{ domain }}{% if not loop.last %},{% endif %}{% endfor %}
 
 KeyFile                 /etc/opendkim/keys/mail.private
-Selector                mail
+Selector                {{ mailfruit_dkim_selector }}
 
 Mode                    sv
 PidFile                 /var/run/opendkim/opendkim.pid

vars/main.yml

@@ -6,3 +6,9 @@ mailfruit_trees_git_ref: 'master'
 # Should you have something running on port 80 already, change this to a certbot
 # plugin that knows better what to do.
 mailfruit_certbot_authenticator: 'standalone'
+
+# The DKIM selector to use. This gets embedded in the DKIM signature in each outbound email,
+# and informs the receiving server what DNS record to query to check the signature.
+# A simple way to deploy this to multiple servers without syncing key material would be to
+# use a distinct value for this variable per-server and host each record independently.
+mailfruit_dkim_selector: 'mail'