Matrix
From Organic Design wiki
Docker installation
First generate a default configuration file for your domain as follows, this will automatically pull the necessary containers as well.
docker run -it --rm --mount type=volume,src=synapse-data,dst=/data -e SYNAPSE_SERVER_NAME=organicdesign.co.nz -e SYNAPSE_REPORT_STATS=yes matrixdotorg/synapse:latest generate
This will create a new volume with your persistent configuration file in it in /var/lib/docker/volumes/synapse-data/_data/homeserver.yaml
Next, run the container on a local-only.
docker run -d --name synapse --mount type=volume,src=synapse-data,dst=/data -p 127.0.0.1:8008:8008 matrixdotorg/synapse:latest
This is the default Matrix port for unsecured HTTP traffic, so that a reverse proxy needs to be set up from your web-server to handle the HTTPS side of things on exposing the default Matrix HTTPS port of 8448 to the public that connects to the the internal HTTP port on 8008. Also there needs to be a connection from port 443, see the official reverse proxy notes for details about the reverse proxy setup.