- Added kubernetes CNI support for Mailu

Signed-off-by: Hans Cornelis <hacornelis@gmail.com>

docs/kubernetes/mailu/configmap.yaml

@@ -53,6 +53,11 @@
     # This way we can make use of the advantages of the cert-manager deployment
     KUBERNETES_INGRESS: "true"
 
+    # POD_ADDRESS_RANGE is normally provided by default with Kubernetes
+    # Only use this value when you are using Flannel, Calico or a special kind of CNI
+    # Provide the IPs of your network interface or bridge which is used for VXLAN network traffic
+    # POD_ADDRESS_RANGE: 10.2.0.0/16,10.1.6.0/24
+
     ###################################
     # Optional features
     ###################################

docs/kubernetes/mailu/index.rst

@@ -191,3 +191,18 @@ This problem can be easily fixed by running following commands:
 
     kubectl -n mailu-mailserver exec -it maolu-imap-... /bin/sh
     chmod 777 /data/main.db
+
+If the login problem still persists, or more specific, happens now and then and you see some Auth problems on your webmail or mail client, try following steps:
+
+- Add ``auth_debug=yes`` to the ``/overrides/dovecot.conf`` file and delete the pod in order to start a new one, which loads the configuration
+- Depending on your network configuration you could still see some ``allow_nets check failed`` results in the logs. This means that the IP is not allowed a login
+- If this is happening your network plugin has troubles with the Nginx Ingress Controller using the ``hostNetwork: true`` option. Known cases: Flannel and Calico.
+- You should uncomment ``POD_ADDRESS_RANGE`` in the ``configmap.yaml`` file and add the IP range of your pod network bridge (the range that sadly has failed the ``allowed_nets`` test)
+- Delete the IMAP pod and wait for it to restart
+
+.. code:: bash
+
+    kubectl -n mailu-mailserver get po
+    kubectl -n mailu-mailserver delete po/mailu-imap...
+
+Happy mailing!