Merge ~hloeung/mailman3-core-charm:master into mailman3-core-charm:master

[Haw Loeung]

Add support for specifying transport maps - LP:1965073

[🤖 Canonical IS Merge Bot (canonical-is-mergebot)]

This merge proposal is being monitored by mergebot. Change the status to Approved to merge.

[James Simpson (jsimpso)]

LGTM

review: Approve

[🤖 Canonical IS Merge Bot (canonical-is-mergebot)]

Change successfully merged at revision e1d0e82266f817034de905e12c47dcd7d7874109

diff --git a/config.yaml b/config.yaml
index a2ebd27..0516192 100644
--- a/config.yaml
+++ b/config.yaml
@@ -97,3 +97,11 @@ options:
     description: |
       A comma-separated list of nagios servicegroups.
       If left empty, the nagios_context will be used as the servicegroup
+  transport_maps:
+    type: string
+    default: ''
+    description: |
+      Optional lookup tables with mappings from recipient address to
+      message delivery transport or next-hop destination.
+
+      http://www.postfix.org/postconf.5.html#transport_maps
diff --git a/reactive/mailman3_core.py b/reactive/mailman3_core.py
index dec185c..42453dd 100644
--- a/reactive/mailman3_core.py
+++ b/reactive/mailman3_core.py
@@ -105,6 +105,12 @@ def configure_postfix():
     subprocess.check_output(['postconf', 'always_add_missing_headers=yes',
                                          'local_header_rewrite_clients=static:all'])
 
+    transport_maps = config.get('transport_maps', '')
+    if transport_maps:
+        host.write_file('/etc/postfix/transport', transport_maps)
+        subprocess.check_output(['postmap', '/etc/postfix/transport'])
+        subprocess.check_output(['postconf', 'transport_maps=hash:/etc/postfix/transport'])
+
     if config["enable_spamassassin"]:
         configure_spamassassin()
     if config["enable_spf"]: