Support for modifying Postfix' master.cf (#595)

* Support for modifying Postfix' master.cf, using the  syntax, in postfix-master.cf

target/start-mailserver.sh

@@ -904,6 +904,16 @@ function _setup_postfix_override_configuration() {
 	else
 		notify 'inf' "No extra postfix settings loaded because optional '/tmp/docker-mailserver/postfix-main.cf' not provided."
 	fi
+	if [ -f /tmp/docker-mailserver/postfix-master.cf ]; then
+		while read line; do
+		if [[ "$line" =~ ^[a-z] ]]; then
+			postconf -P "$line"
+		fi
+		done < /tmp/docker-mailserver/postfix-master.cf
+		notify 'inf' "Loaded 'config/postfix-master.cf'"
+	else
+		notify 'inf' "No extra postfix settings loaded because optional '/tmp/docker-mailserver/postfix-master.cf' not provided."
+	fi
 }
 
 function _setup_postfix_sasl_password() {

test/config/postfix-master.cf

@@ -0,0 +1 @@
+submission/inet/smtpd_sasl_security_options=noanonymous

test/tests.bats

@@ -391,6 +391,11 @@ load 'test_helper/bats-assert/load'
   assert_success
 }
 
+@test "checking postfix: master.cf overrides" {
+  run docker exec mail grep -q 'submission/inet/smtpd_sasl_security_options=noanonymous' /tmp/docker-mailserver/postfix-master.cf
+  assert_success
+}
+
 #
 # dovecot
 #