Synology - Matrix - Synapse Homeserver

To install the synapse server you have either create the config file (homeserver.yaml) manually or let synapse create an initial config files as described below...

Download the Docker-Image matrixdotorg/synapse:

Create a new Container:

Network: bridge

General Settings:

Set Container name.
If you are here the first time DO NOT SET "Enable auto-restart". Enable auto-restart AFTER the config files were created sucessfully!
Go to Advanced Settings...

Add variables:

SYNAPSE_SERVER_NAME=your.host.name
SYNAPSE_REPORT_STATS=yes

Add command:

generate

This is necessary to create the initial config files. SKIP THIS STEP THE SECOND TIME you are here. Otherwise Synapse will not start...

Set the ports i.e. 10001-3

Add persistent data folder

Add a new (or empty) folder i.e. synapse_data on an appropriate device and mount it to /data: This folder will contain all data, i.e. config, message-db....

Finish with "Run this container..."

Container will stop after a short time, after having created the config files. Do not re-start the container!

Verify that the initial config has been created

Delete Container

You have to delete the Conatiner and re-create it, because the generate-Command can not be edited (or removed in this case). Maybe in a later Docker-GUI-Version...

Re-Create Container without generate-Command

Repeat the whole process without setting command generate and without deleting the Container...

Check if Synapse is up and running:

Go to http://[IP of your Synology]:[PORT i.e. 10001]

Create a (first) admin user:res

Enter register_new_matrix_user http://localhost:8008 -c /data/homeserver.yaml in a new console
Enter name and password for admin user
Make admin: yes