Guide to Customize Synapse Homeserver.yaml

The Config

In my previous post, Setup Guide: Self-Hosted Synapse Matrix with Docker I posted a bare bones homeserver.yaml file for your Synapse instance. In this post we’ll go over a few of the changes that were made and why I choose to make them.

my-domain

First, we’ll get a few of the more obvious ones out of the way. Anything from the config in the previous post that has my-domain should be changed to the domain you intend to use. If you don’t have one you can use a service like DynDNS or DuckDNS to setup an agent and provide a free sub-domain name with their services. Be sure to remember what that is later for testing, and make sure you have it pointed to your instance public facing IP.

base64

Next, we’ll talk about the base64 keys. We wanted to have something random and long for these keys to ensure some level of security and anonymity. If you Google base64 bit string generators you can find a few different services, even easier is using this command in bash

dd if=/dev/urandom bs=1024 count=1 status=none | base64

Email Server

If you choose to use email for registration and validation of accounts you’ll want to use an SMTP service, either self-hosted or cloud-based depending on your setup or needs, in the past I’ve used mailjet.

Third Party ID

Along with the email server, you can also turn on email and a third-party id, or verification method for new accounts.

registrations_require_3pid:
  - email

Metrics

If you want to see prometheus metrics you can enable that with the following:

enable_metrics: true

Just be sure to add the following into your NPM instance if you’re using that, the below config blocks those metrics from the outside world.

location /_synapse/metrics{
  try_files $uri = 404;
}

Presence

This is a personal preference but it is nice to see if someone is online that you’re talking to or “AFK”.

presence:
  enabled: true

Federating

If you want to federate, as I do, and interconnect better with other servers you’ll want to enable this setting in homeserver.yaml

allow_public_rooms_over_federation: true

You’ll also want to add this to your NPM config

location /.well-known/matrix/server {
    return 200 '{"m.server": "matrix.saltyoldgeek.com:443"}';
    default_type application/json;
    add_header Access-Control-Allow-Origin *;
}

Wrap-up

That should about wrap this up, if this was helpful let me know. Till the next one, fair winds and following seas.