Parametrize hosts

Allows to use mailu without docker-compose when hostnames are not set up
by docker itself but provided via a separate resolver.

Use case: use mailu using nomad scheduler and consul resolver instead of
docker-compose. Other servers are provided by the DNS resolver that
resolves names like admin.service.consul or webmail.service.consul.
These names needs to be configurable.

core/admin/mailu/__init__.py

@@ -54,6 +54,11 @@ default_config = {
     'WEB_WEBMAIL': '/webmail',
     # Advanced settings
     'PASSWORD_SCHEME': 'SHA512-CRYPT',
+    # Host settings
+    'HOST_IMAP': 'imap',
+    'HOST_POP3': 'imap',
+    'HOST_SMTP': 'smtp',
+    'HOST_AUTHSMTP': os.environ.get('HOST_SMTP', 'smtp'),
 }
 
 # Load configuration from the environment if available

core/admin/mailu/internal/nginx.py

@@ -1,5 +1,6 @@
-from mailu import db, models
+from mailu import db, models, app
 
+import re
 import socket
 import urllib
 
@@ -73,14 +74,19 @@ def get_status(protocol, status):
     status, codes = STATUSES[status]
     return status, codes[protocol]
 
+def extract_host_port(host_and_port, default_port):
+    host, _, port = re.match('^(.*)(:([0-9]*))?$', host_and_port).groups()
+    return host, int(port) if port else default_port
 
 def get_server(protocol, authenticated=False):
     if protocol == "imap":
-        hostname, port = "imap", 143
+        hostname, port = extract_host_port(app.config['HOST_IMAP'], 143)
     elif protocol == "pop3":
-        hostname, port = "imap", 110
+        hostname, port = extract_host_port(app.config['HOST_POP3'], 110)
     elif protocol == "smtp":
-        hostname = "smtp"
-        port = 10025 if authenticated else 25
+        if authenticated:
+            hostname, port = extract_host_port(app.config['HOST_AUTHSMTP'], 10025)
+        else:
+            hostname, port = extract_host_port(app.config['HOST_SMTP'], 25)
     address = socket.gethostbyname(hostname)
     return address, port

core/nginx/conf/nginx.conf

@@ -37,10 +37,10 @@ http {
     # Main HTTP server
     server {
       # Variables for proxifying
-      set $admin admin;
-      set $antispam antispam:11334;
-      set $webmail webmail;
-      set $webdav webdav:5232;
+      set $admin {{ HOST_ADMIN }};
+      set $antispam {{ HOST_ANTISPAM }};
+      set $webmail {{ HOST_WEBMAIL }};
+      set $webdav {{ HOST_WEBDAV }};
 
       # Always listen over HTTP
       listen 80;

core/nginx/config.py

@@ -12,6 +12,14 @@ with open("/etc/resolv.conf") as handle:
     content = handle.read().split()
     args["RESOLVER"] = content[content.index("nameserver") + 1]
 
+if "HOST_WEBMAIL" not in args:
+    args["HOST_WEBMAIL"] = "webmail"
+if "HOST_ADMIN" not in args:
+    args["HOST_ADMIN"] = "admin"
+if "HOST_WEBDAV" not in args:
+    args["HOST_WEBDAV"] = "webdav:5232"
+if "HOST_ANTISPAM" not in args:
+    args["HOST_ANTISPAM"] = "antispam:11334"
 
 # TLS configuration
 args["TLS"] = {

docs/configuration.rst

@@ -69,3 +69,21 @@ Advanced settings
 The ``PASSWORD_SCHEME`` is the password encryption scheme. You should use the
 default value, unless you are importing password from a separate system and
 want to keep using the old password encryption scheme.
+
+Infrastructure settings
+-----------------------
+
+Various environment variables ``HOST_*`` can be used to run Mailu containers
+separately from a supported orchestrator. It is used by the various components
+to find the location of the other containers it depends on. They can contain an
+optional port number. Those variables are:
+
+- ``HOST_IMAP``: the container that is running the IMAP server (default: ``imap``, port 143)
+- ``HOST_POP3``: the container that is running the POP3 server (default: ``imap``, port 110)
+- ``HOST_SMTP``: the container that is running the SMTP server (default: ``smtp``, port 25)
+- ``HOST_AUTHSMTP``: the container that is running the authenticated SMTP server for the webnmail (default: ``smtp``, port 10025)
+- ``HOST_ADMIN``: the container that is running the admin interface (default: ``admin``)
+- ``HOST_ANTISPAM``: the container that is running the antispam service (default: ``antispam:11334``)
+- ``HOST_WEBMAIL``: the container that is running the webmail (default: ``webmail``)
+- ``HOST_WEBDAV``: the container that is running the webdav server (default: ``webdav:5232``)
+