Revert "Revert accidental docker->master merge"

This reverts commit db834b581e.

README.md

@@ -4,6 +4,7 @@ the database postgresql and the css library bootstrap as well as the icon packag
 fontawesome for a modern look, following best practices from the industry.
 
 ## Background processes
+### !!! For non-docker run
 Konova uses celery for background processing. To start the worker you need to run
 ```shell
 $ celery -A konova worker -l INFO
@@ -18,3 +19,58 @@ Technical documention is provided in the projects git wiki.
 A user documentation is not available (and not needed, yet). 
 
 
+# Docker 
+To run the docker-compose as expected, you need to take the following steps:
+
+1. Create a database containing docker, using an appropriate Dockerfile, e.g. the following
+```
+version: '3.3'
+services:
+  postgis:
+    image: postgis/postgis
+    restart: always
+    container_name: postgis-docker
+    ports: 
+      - 5433:5432
+    volumes:
+      - db-volume:/var/lib/postgresql/data
+    environment:
+      - POSTGRES_PASSWORD=postgres
+      - POSTGRES_USER=postgres
+    networks:
+      - db-network-bridge
+
+networks:
+  db-network-bridge:
+    driver: "bridge"
+
+volumes:
+  db-volume:
+```
+This Dockerfile creates a Docker container running postgresql and postgis, creates the default superuser postgres, 
+creates a named volume for persisting the database and creates a new network bridge, which **must be used by any other
+container, which wants to write/read on this database**. 
+
+2. Make sure the name of the network bridge above matches the network in the konova docker-compose.yml  
+3. Get into the running postgis container (`docker exec -it postgis-docker bash`) and create new databases, users and so on. Make sure the database `konova` exists now!
+4. Replace all `CHANGE_ME_xy` values inside of konova/docker-compose.yml for your installation. Make sure the `SSO_HOST` holds the proper SSO host, e.g. for the arnova project `arnova.example.org` (Arnova must be installed and the webserver configured as well, of course)
+5. Take a look on konova/settings.py and konova/sub_settings/django_settings.py. Again: Replace all occurences of `CHANGE_ME` with proper values for your installation.
+   1. Make sure you have the proper host strings added to `ALLOWED_HOSTS` inside of django_settings.py.  
+6. Build and run the docker setup using `docker-compose build` and `docker-compose start` from the main directory of this project (where the docker-compose.yml lives)
+7. Run migrations! To do so, get into the konova service container (`docker exec -it konova-docker bash`) and run the needed commands (`python manage.py makemigrations LIST_OF_ALL_MIGRATABLE_APPS`, then `python manage.py migrate`)
+8. Run the setup command `python manage.py setup` and follow the instructions on the CLI
+9. To enable **SMTP** mail support, make sure your host machine (the one where the docker container run) has the postfix service configured properly. Make sure the `mynetworks` variable is xtended using the docker network bridge ip, created in the postgis container and used by the konova services.
+   1. **Hint**: You can find out this easily by trying to perform a test mail in the running konova web application (which will fail, of course). Then take a look to the latest entries in `/var/log/mail.log` on your host machine. The failed IP will be displayed there.
+   2. **Please note**: This installation guide is based on SMTP using postfix! 
+   3. Restart the postfix service on your host machine to reload the new configuration (`service postfix restart`)
+10. Finally, make sure your host machine webserver passes incoming requests properly to the docker nginx webserver of konova. A proper nginx config for the host machine may look like this:
+```
+server {
+    server_name konova.domain.org;
+
+    location / {
+        proxy_pass http://localhost:KONOVA_NGINX_DOCKER_PORT/;
+        proxy_set_header Host $host;
+    }
+}
+```