Add a domain aliases mechanism to lists.o.o

In order to be able to redirect list addresses which have moved from
one domain to another, we need a solution to alias the old addresses
to the new ones. We have simple aliases but they only match on the
local part. Add a new /etc/aliases.domain which matches full
local_part@domain addresses instead. Also collect this file in the
Mailman deployment test for ease of inspection.

Change-Id: I16f871e96792545e1a8cc8eb3834fa4eb82e31c8

inventory/service/host_vars/lists.openstack.org.yaml

@@ -34,6 +34,7 @@ exim_aliases:
   superuser-owner: spam
   user-committee-owner: spam
   spam: ':fail: delivery temporarily disabled due to ongoing spam flood'
+exim_domain_aliases: {}
 exim_routers:
   - mailman_verp_router: |
       {% raw -%}
@@ -51,6 +52,13 @@ exim_routers:
       transport = mailman_verp_smtp
   - dnslookup: '{{ exim_dnslookup_router }}'
   - system_aliases: '{{ exim_system_aliases_router }}'
+  - domain_aliases: |
+      driver = redirect
+      allow_fail
+      allow_defer
+      data = ${lookup{$local_part@$domain}lsearch{/etc/aliases.domain}}
+      file_transport = address_file
+      pipe_transport = address_pipe
   - localuser: '{{ exim_localuser_router }}'
   - mailman_copy: |
       driver = accept

playbooks/roles/mailman/tasks/main.yaml

@@ -91,6 +91,11 @@
       loop: "{{ mailman_sites }}"
       loop_control:
         loop_var: site
+    - name: Write /etc/aliases.domain
+      template:
+        src: "domain_aliases.j2"
+        dest: "/etc/aliases.domain"
+        mode: 0444
   when: mailman_multihost
 
 - name: normal mailman configs

playbooks/roles/mailman/templates/domain_aliases.j2

@@ -0,0 +1,6 @@
+# /etc/aliases.domain
+{% for k, v in exim_domain_aliases|dictsort %}
+{% if v %}
+{{ k }}: {{ v }}
+{% endif %}
+{% endfor %}

zuul.d/system-config-run.yaml

@@ -270,6 +270,7 @@
           '/var/log/mailman': logs
       lists.openstack.org:
         host_copy_output:
+          '/etc/aliases.domain': logs_txt
           '/var/log/mailman': logs
 
 - job: