cluster/prod/app/email/config/postfix/main.cf

@@ -83,11 +83,14 @@ smtpd_forbid_unauth_pipelining = yes
 smtpd_discard_ehlo_keywords = chunking
 smtpd_forbid_bare_newline = yes
 
-smtpd_client_connection_rate_limit = 2
-
 #===
 # Rate limiting
 #===
+smtpd_client_connection_rate_limit = 2
+# do not rate-limit ourselves
+# in particular, useful for forgejo who opens a lot of SMTP connections
+smtpd_client_event_limit_exceptions = $mynetworks /etc/postfix/rate-limit-exceptions
+
 slow_destination_recipient_limit = 20
 slow_destination_concurrency_limit = 2
 

cluster/prod/app/email/deploy/email.hcl

@@ -382,6 +382,29 @@ job "email" {
         destination = "secrets/postfix/transport"
       }
 
+      template {
+        # Collect machine IPs from the cluster.
+        # We use intermediate maps to ensure we get a sorted list with no duplicates,
+        # so that it is robust wrt. changes in the order of the output of ls or
+        # addition of new machines in an existing site.
+        # (scratch.MapValues returns the list of *values* in the map, sorted by *key*)
+        data = <<EOH
+        {{- range ls "diplonat/autodiscovery/ipv4" }}
+          {{- with $a := .Value | parseJSON }}
+            {{- scratch.MapSet "ipv4" $a.address $a.address }}
+          {{- end }}
+        {{- end -}}
+        {{- range ls "diplonat/autodiscovery/ipv6" }}
+          {{- with $a := .Value | parseJSON }}
+            {{- scratch.MapSet "ipv6" $a.address $a.address }}
+          {{- end }}
+        {{- end -}}
+        {{- range scratch.MapValues "ipv4" }}{{ . }} {{ end }}
+        {{- range scratch.MapValues "ipv6" }}[{{ . }}] {{ end }}
+        EOH
+        destination = "secrets/postfix/rate-limit-exceptions"
+      }
+
       # --- secrets ---
       template {
         data = "{{ with $d := key \"tricot/certs/smtp.deuxfleurs.fr\" | parseJSON }}{{ $d.cert_pem }}{{ end }}"