Enhance description with relation between containers (#243)

* add container structure as architecture document and link to it from the readme
* have separate architecture description for Meet

README.md

@@ -14,6 +14,8 @@ This repository contains an easy to replicate recipe to spin up a [Kopano](https
 - after startup has succeeded you can access the Kopano WebApp by going to `https://kopano.demo/webapp`
 - there are already some users created in the demo ldap. These users all have a password that is identical to the username, e.g. the password for `user1` user `user1`.
 
+If you want to get an impression how the containers interact/relate with each other have a look at the [architecture](architecture.md) description.
+
 **Note:** There have been reports about the ldap demo not starting up on MacOS. It is recommended to use a Linux OS if you want to use the bundled LDAP image. 
 
 The `docker-compose.yml` file by default pulls Docker containers from https://hub.docker.com/r/zokradonh/kopano_core/ and https://hub.docker.com/r/zokradonh/kopano_webapp/. These images are based on the [Kopano nightly builds](https://download.kopano.io/community/) and will contain the latest version available from the time the image was built.

architecture.md

@@ -0,0 +1,103 @@
+# Architecture Overview
+
+Aka "How do the containers connect/relate/interact with each other?"
+
+## web
+
+- external entry point for users accessing Kopano
+    - reverse proxy for containers exposing a web interface 
+- can retrieve ssl certificate from Let's Encrypt
+- redirects all requests to /webapp by default
+- recommended to use as it makes web configuration easy and secure (manual configuration will be tendious and potentially less secure)
+
+## ldap
+
+- (optional) bundles OpenLDAP service
+- kopano_server is using LDAP to manage users
+
+## ldap-admin and password-self-service
+
+- optional containers to manage users in ldap and let users change their password
+
+## mail
+
+- MTA stack with anti-spam and anti-virus
+- connects against the ldap to verify users
+
+## db
+
+- (optional) bundles MariaDB for the Kopano database
+
+## kopano_ssl
+
+- helper container to generate ssl certificates for internal usage
+- will create required files and then stop
+
+## kopano_server
+
+- main process of the Kopano deployment
+- connects towards LDAP to get a list of users and verify user logins via bind
+
+## kopano_webapp
+
+- provides Kopano WebApp, so users can interact with their mailboxes via their browser
+
+## kopano_zpush
+
+- provides Z-Push, so users can sync their mailboxes to phones and tablets
+
+## kopano_grapi
+
+- groupware backend of the Kopano RestAPI
+
+## kopano_kapi
+
+- http endpoint of the Kopano RestAPI
+- stores recent calls for the user in a key value stores (queried over Rest)
+
+## kopano_kdav
+
+- provides KDav, so users can sync their calendars and contacts via CalDAV and CardDAV
+
+## kopano_dagent
+
+- mail delivery part for kopano_server
+- mta delivers mail to it, dagent delivers the mail into the desired inbox
+
+## kopano_spooler
+
+- mail sending part for kopano_server
+- monitors outboxes of users, submits mails to the mta
+
+## kopano_gateway
+
+- provides Pop3 and IMAP access for users
+
+## kopano_ical
+
+- provides iCAL and CalDAV access for users (will be replaced with KDav in the future)
+
+## kopano_monitor
+
+- monitors mailbox usage and sends quota mails (by directly delivering a mail into the users inbox)
+
+## kopano_search
+
+- provides full text indexing for mailboxes
+
+## kopano_konnect
+
+- authentification component (OpenID Connect)
+- required for apps interacting with the Kopano RestAPI (e.g. Kopano Meet)
+
+## kopano_kwmserver
+
+- WebRTC signalling server
+
+## kopano_meet
+
+- provides the Meet web application/frontend
+
+## kopano_scheduler
+
+- helper container to execute scheduled tasks within Kopano

examples/meet/architecture.md

@@ -0,0 +1,42 @@
+# Architecture Overview
+
+## web
+
+- external entry point for users accessing Kopano Meet
+    - reverse proxy for kopano_kapi, kopano_konnect, kopano_kwmserver and kopano_meet 
+- can retrieve ssl certificate from Lets Encrypt
+- redirects all requests to /meet
+- recommended to use as it makes web configuration easy and secure (manual configuration will be tendious and potentially less secure)
+
+## ldap
+
+- (optional) bundles OpenLDAP service
+- Konnect and Grapi are using it
+
+## kopano_ssl
+
+- helper container to generate ssl certificates for internal usage
+- will create required files and then stop
+
+## kopano_grapi
+
+- groupware backend of the Kopano RestAPI
+- connects to LDAP to provide a global addressbook to users
+
+## kopano_kapi
+
+- http endpoint of the Kopano RestAPI
+- stores recent calls for the user in a key value stores (queried over Rest)
+
+## kopano_konnect
+
+- authentification component (OpenID Connect) for Meet
+- connects to the LDAP backend to verify user logins via bind
+
+## kopano_kwmserver
+
+- WebRTC signalling server
+
+## kopano_meet
+
+- provides the Meet web application/frontend