Force a postfix restart after a configuration change without waiting for the handlers to kick in. Add 'compatibility_level=2' on Ubuntu 18.04.

library/roles/postfix-relay/tasks/smtp-common-packages.yml

@@ -14,21 +14,31 @@
 
     - name: Write the postfix main configuration file
       template: src=main.cf.j2 dest=/etc/postfix/main.cf owner=root group=root mode=0444
-      notify: Restart postfix
+      register: postfix_main_restart_needed
 
     - name: Activate the submission port on the postfix master file
       template: src=postfix-master.cf.j2 dest=/etc/postfix/master.cf owner=root group=root mode=0444
-      notify: Restart postfix
+      register: postfix_master_restart_needed
 
+  when: postfix_install_packages | bool
+  tags: postfix-relay 
+
+- block:
     - name: Ensure that postfix is started and enabled
       service: name=postfix state=started enabled=yes
-      when: postfix_enabled
+      when: postfix_enabled | bool
 
     - name: Ensure that postfix is stopped and disabled
       service: name=postfix state=stopped enabled=no
-      when: not postfix_enabled
+      when: not postfix_enabled | bool
 
-  when: postfix_install_packages
+    - name: Restart postfix
+      service: name=postfix state=restarted
+      when: ( postfix_main_restart_needed is changed ) or ( postfix_master_restart_needed is changed )
+
+  when:
+    - postfix_install_packages | bool
+    - postfix_enabled | bool
   tags: postfix-relay 
 
 - block:
@@ -41,8 +51,8 @@
       notify: Reload NRPE server
 
   when:
-    - postfix_install_packages
-    - postfix_nagios_check
+    - postfix_install_packages | bool
+    - postfix_nagios_check | bool
   tags: [ 'postfix-relay', 'nagios', 'nrpe' ]
 
 - block:
@@ -54,5 +64,5 @@
       yum: pkg={{ postfix_relay_rh_pkgs }} state=absent
       when: ansible_distribution_file_variety == "RedHat"
 
-  when: not postfix_install_packages
+  when: not postfix_install_packages | bool
   tags: postfix-relay 

library/roles/postfix-relay/templates/main.cf.j2

@@ -63,10 +63,12 @@ smtp_sasl_password_maps = hash:/etc/postfix/sasl_passwd
 smtp_sasl_security_options = {{ postfix_smtp_sasl_security_options }}
 smtp_sasl_tls_security_options = {{ postfix_smtp_sasl_tls_security_options }}
 smtp_sasl_mechanism_filter = {{ postfix_smtp_sasl_mechanism_filter }}
-{% if ansible_distribution_major_version >= '18' %}
+{% if ansible_distribution_file_variety == "Debian" %}
+{% if ansible_distribution_version is version_compare('18.04', '>=') %}
 smtpd_relay_restrictions = permit_mynetworks, defer_unauth_destination
 {% endif %}
 {% endif %}
+{% endif %}
 {% if postfix_relay_server %}
 smtpd_sasl_path = smtpd
 smtpd_sasl_auth_enable = yes
@@ -92,3 +94,8 @@ smtpd_sender_restrictions = reject_unknown_sender_domain
 # authenticated clients may specify any destination domain.
 smtpd_relay_restrictions = permit_sasl_authenticated, reject
 {% endif %}
+{% if ansible_distribution_file_variety == "Debian" %}
+{% if ansible_distribution_version is version_compare('18.04', '>=') %}
+compatibility_level=2
+{% endif %}
+{% endif %}