Setup mailman3 server

We want to migrate to mailman3 as mailman2 is basically unmaintained and requires Python 2 which is EOL.

Because the mailman and mailman3 packages conflict and we don't want to perform a big bang migration, mailman3 must be deployed on a separate server. mailman-web (mailman3's web interface) hasn't been packaged yet, so for now we are using my homebrewed PKGBUILD.

[1] https://gist.github.com/klausenbusk/5982063f95c503754a51ed2fefb8915e

Ref #59 (closed)

---

Migrated lists:

• arch-announce
• arch-devops-private
• arch-events
• arch-wiki-admins

roles/mailman3/templates/nginx.d.conf.j2

@@ -3,10 +3,8 @@ server {
     listen       [::]:80;
     server_name  {{ lists_domain }};
 
-    # allow, deny. X-Forwarded-For
-    # client_max_body_size
     set_real_ip_from {{ hostvars['lists.archlinux.org']['wireguard_address'] }}/32;
-    real_ip_header   proxy_protocol;
+    real_ip_header   X-Forwarded-For;
 
     access_log   /var/log/nginx/{{ lists_domain }}/access.log main;
     access_log   /var/log/nginx/{{ lists_domain }}/access.log.json json_main;