fix: Workaround postconf write settling logic (#2998)

* fix: Workaround `postconf` write settle logic

After updating `main.cf`, to avoid an enforced delay from reading the config by postfix tools, we can ensure the modified time is at least 2 seconds in the past as a workaround. This should be ok with our usage AFAIK.

Shaves off 2+ seconds roughly off each container startup, reduces roughly 2+ minutes off tests.

* chore: Only modify `mtime` if less than 2 seconds ago

- Slight improvement by avoiding unnecessary writes with a conditional check on the util method.
- Can more comfortably call this during `postfix reload` in the change detection cycle now.
- Identified other tests that'd benefit from this, created a helper method to call instead of copy/paste.
- The `setup email restrict` command also did a modification and reload. Added util method here too.

* tests(fix): `mail_smtponly.bats` should wait for Postfix

- `postfix reload` fails if the service is not ready yet.
- `service postfix reload` and `/etc/init.d/postfix reload` presumably wait until it is ready? (as these work regardless)

* chore: Review feedback - Move reload method into utilities

test/tests/parallel/set1/spam_virus/postgrey_enabled.bats

@@ -48,11 +48,13 @@ function teardown_file() { _default_teardown ; }
 @test "should initially reject (greylist) mail from 'user@external.tld'" {
   # Modify the postfix config in order to ensure that postgrey handles the test e-mail.
   # The other spam checks in `main.cf:smtpd_recipient_restrictions` would interfere with testing postgrey.
-  _run_in_container bash -c "sed -ie 's/permit_sasl_authenticated.*policyd-spf,$//g' /etc/postfix/main.cf"
-  _run_in_container bash -c "sed -ie 's/reject_unauth_pipelining.*reject_unknown_recipient_domain,$//g' /etc/postfix/main.cf"
-  _run_in_container bash -c "sed -ie 's/reject_rbl_client.*inet:127\.0\.0\.1:10023$//g' /etc/postfix/main.cf"
-  _run_in_container bash -c "sed -ie 's/smtpd_recipient_restrictions =/smtpd_recipient_restrictions = check_policy_service inet:127.0.0.1:10023/g' /etc/postfix/main.cf"
-  _run_in_container postfix reload
+  _run_in_container sed -i \
+    -e 's/permit_sasl_authenticated.*policyd-spf,$//g' \
+    -e 's/reject_unauth_pipelining.*reject_unknown_recipient_domain,$//g' \
+    -e 's/reject_rbl_client.*inet:127\.0\.0\.1:10023$//g' \
+    -e 's/smtpd_recipient_restrictions =/smtpd_recipient_restrictions = check_policy_service inet:127.0.0.1:10023/g' \
+    /etc/postfix/main.cf
+  _reload_postfix
 
   # Send test mail (it should fail to deliver):
   _send_test_mail '/tmp/docker-mailserver-test/email-templates/postgrey.txt' '25'

test/tests/serial/mail_smtponly.bats

@@ -9,6 +9,7 @@ function setup_file() {
     -t "${NAME}"
 
   wait_for_finished_setup_in_container mail_smtponly
+  wait_for_smtp_port_in_container mail_smtponly
 }
 
 function teardown_file() {
@@ -45,8 +46,8 @@ function teardown_file() {
 @test "checking smtp_only: mail send should work" {
   run docker exec mail_smtponly /bin/sh -c "postconf smtp_host_lookup=no"
   assert_success
-  run docker exec mail_smtponly /bin/sh -c "/etc/init.d/postfix reload"
-  assert_success
+
+  _reload_postfix mail_smtponly
 
   wait_for_smtp_port_in_container mail_smtponly
   run docker exec mail_smtponly /bin/sh -c "nc 0.0.0.0 25 < /tmp/docker-mailserver-test/email-templates/smtp-only.txt"

test/tests/serial/permit_docker.bats

@@ -65,8 +65,7 @@ teardown_file() {
   run docker exec mail_smtponly_second_network /bin/sh -c "postconf smtp_host_lookup=no"
   assert_success
 
-  run docker exec mail_smtponly_second_network /bin/sh -c "/etc/init.d/postfix reload"
-  assert_success
+  _reload_postfix mail_smtponly_second_network
 
   # we should be able to send from the other container on the second network!
   run docker exec mail_smtponly_second_network_sender /bin/sh -c "nc mail_smtponly_second_network 25 < /tmp/docker-mailserver-test/email-templates/smtp-only.txt"
@@ -78,8 +77,7 @@ teardown_file() {
   run docker exec mail_smtponly_force_authentication /bin/sh -c "postconf smtp_host_lookup=no"
   assert_success
 
-  run docker exec mail_smtponly_force_authentication /bin/sh -c "/etc/init.d/postfix reload"
-  assert_success
+  _reload_postfix mail_smtponly_force_authentication
 
   # the mailserver should require authentication and a protocol error should occur when using TLS
   run docker exec mail_smtponly_force_authentication /bin/sh -c "nc localhost 25 < /tmp/docker-mailserver-test/email-templates/smtp-only.txt"