roles/nextcloud: Configure outbound email

Since the Nextcloud configuration file is managed by the configuration
policy, all of the settings configurable through the web UI need to be
templated.  One important group of settings is the outbound email
configuration.  This can now be configured using the `nextcloud_smtp`
Ansible variable.

group_vars/nextcloud.yml

@@ -13,3 +13,7 @@ nextcloud_trusted_domains:
 - nextcloud.pyrocufflink.net
 - nextcloud.pyrocufflink.blue
 - '{{ ansible_fqdn }}'
+nextcloud_smtp:
+  from: nextcloud@pyrocufflink.net
+  host: mail.pyrocufflink.blue
+  port: 25

roles/nextcloud/templates/config.php.j2

@@ -49,6 +49,14 @@ $CONFIG = array (
   'maintenance' => {{ nextcloud_maintenance|bool|string|lower }},
   'theme' => '',
   'loglevel' => 2,
+{% if nextcloud_smtp is defined %}
+  'mail_from_address' => '{{ nextcloud_smtp.from.split("@")[0] }}',
+  'mail_smtpmode' => 'smtp',
+  'mail_sendmailmode' => 'smtp',
+  'mail_domain' => '{{ nextcloud_smtp.from.split("@")[1] }}',
+  'mail_smtphost' => '{{ nextcloud_smtp.host }}',
+  'mail_smtpport' => '{{ nextcloud_smtp.port }}',
+{% endif %}
   'filelocking.enabled' => true,
   'memcache.distributed' => '\OC\Memcache\Redis',
   'memcache.locking' => '\OC\Memcache\Redis',