Traefik: introduce domain redirect

Author: YuryHrytsuk

services/traefik/docker-compose.yml.j2

@@ -146,6 +146,28 @@ services:
         - traefik.http.middlewares.strip-www.redirectregex.replacement=$${1}://$${2}
         - traefik.http.middlewares.strip-www.redirectregex.permanent=true
 
+
+        ###
+        # Domain redirects
+        ###
+{% set redirect_from_domains_list = TRAEFIK_DOMAINS_REDIRECT_FROM.split(',') %}
+{% set redirect_to_domains_list = TRAEFIK_DOMAINS_REDIRECT_TO.split(',') %}
+
+{% for from_domain, to_domain in zip(redirect_from_domains_list, redirect_to_domains_list) %}
+{% set from_domain_no_dots = from_domain.replace(".", "-") %}
+        # Regex below is redirecting any subdomains and path to new domain.
+        #     Use https://regex101.com/r/58sIgx/2 for regex explanation and experimentation.
+        #     Below we include dollar escaping and j2 expressions. It is not clean / pure regex
+        #     You can fetch baked and clean regex from traefik dashboards.
+        - traefik.http.middlewares.redirect-{{ from_domain_no_dots }}.redirectregex.regex=^https?://((?:[a-zA-Z0-9-]+\.)*)*{{ from_domain }}(.*)$$
+        - traefik.http.middlewares.redirect-{{ from_domain_no_dots }}.redirectregex.replacement=https://$${1}{{ to_domain }}$${2}
+        - traefik.http.middlewares.redirect-{{ from_domain_no_dots }}.redirectregex.permanent=false
+        - traefik.http.routers.{{ from_domain_no_dots }}.rule={{ generate_domain_capture_all_rule(from_domain) }}
+        - traefik.http.routers.{{ from_domain_no_dots }}.middlewares=redirect-{{ from_domain_no_dots }}
+        - traefik.http.routers.{{ from_domain_no_dots }}.entrypoints=https
+        - traefik.http.routers.{{ from_domain_no_dots }}.tls=true
+{% endfor %}
+
     networks:
       public: null
       monitored: null

services/traefik/j2cli_customization.py

@@ -0,0 +1,23 @@
+def _generate_domain_capture_all_rule(domain: str) -> str:
+    rules = [
+        f"Host(`{domain}`)",
+        f"Host(`www.{domain}`)",
+        f"Host(`invitations.{domain}`)",
+        f"Host(`services.{domain}`)",
+        f"HostRegexp(`{{subhost:[a-zA-Z0-9-]+}}.services.{domain}`)",
+        f"Host(`services.testing.{domain}`)",
+        f"HostRegexp(`{{subhost:[a-zA-Z0-9-]+}}.services.testing.{domain}`)",
+        f"Host(`pay.{domain}`)",
+        f"Host(`api.{domain}`)",
+        f"Host(`api.testing.{domain}`)",
+        f"Host(`testing.{domain}`)",
+    ]
+    return " || ".join(rules)
+
+
+def j2_environment(env):
+    env.globals.update(
+        generate_domain_capture_all_rule=_generate_domain_capture_all_rule,
+        zip=zip,
+    )
+    return env

services/traefik/template.env

@@ -37,3 +37,6 @@ MONITORED_NETWORK=${MONITORED_NETWORK}
 
 WEBSERVER_HOST=${WEBSERVER_HOST}
 WEBSERVER_PORT=${WEBSERVER_PORT}
+
+TRAEFIK_DOMAINS_REDIRECT_FROM=
+TRAEFIK_DOMAINS_REDIRECT_TO=