move PostgreSQL stuff to "distro specific" page, as it's not trouble-shooting or recommendations

19.1-Release-notes-and-distribution-specific-instructions.md

@@ -100,6 +100,17 @@ yum update
 > RHEL/CentOS does not provide a docker-compose package/command, therefore we provide one in our repository.
 
 # PostgreSQL
-There is has been no testing with PostgreSQL and 19.1 so far, but we have a couple of bug reports / SQL errors in ProjectManager. 
 
-> While more testing is appreciated, do NOT update a production instance yet!
+> Keep in mind, that you can NOT use ```localhost``` to address a service eg. PostgreSQL inside the container, as it does NOT refer to the host, but the container itself. You have to use the IP address of the host or the docker0 bridge AND make sure the service is not just bound to localhost!
+
+While an update of a PostgreSQL instance works similar to MariaDB/MySQL, a new installation does not happen automatic!
+1. Edit /etc/egroupware-docker/docker-compose.yml and add the following to the [environment section](https://github.com/EGroupware/build.opensuse.org/blob/master/server:eGroupWare/egroupware-docker-19.1/egroupware-docker/docker-compose.yml#L44): 
+```
+- EGW_SKIP_INSTALL=true
+```
+2. remove the header.inc.php, so EGW_SKIP_INSTALL takes effect
+```
+rm -f /var/lib/egroupware/header.inc.php
+```
+3. start the containers as usual with: ```docker-compose up -d```
+4. Go to http://example.org/egroupware/setup/ and do a manual installation