opensmtpd: support relaying mail

roles/opensmtpd/handlers/main.yml

@@ -0,0 +1,5 @@
+- name: restart smtpd
+  service:
+    name: smtpd
+    state: restarted
+  when: "'handler' not in ansible_skip_tags"

roles/opensmtpd/tasks/main.yml

@@ -1,7 +1,15 @@
+# this role is currently for alpine linux only
+
 - name: Install mail server
   package:
     name: opensmtpd
 
+- name: Configure mail server
+  template:
+    dest: /etc/smtpd/smtpd.conf
+    src: smtpd.conf.j2
+  notify: restart smtpd
+
 - name: Enable mail server
   service:
     name: smtpd

roles/opensmtpd/templates/smtpd.conf.j2

@@ -0,0 +1,9 @@
+table aliases file:/etc/smtpd/aliases
+
+listen on lo
+
+action "local" maildir alias <aliases>
+action "relay" relay{% if mail_relay is defined %} host smtp+tls://{{ mail_relay }}{% endif +%}
+
+match for local action "local"
+match from local for any action "relay"