mirror of
https://github.com/matrix-org/dendrite
synced 2024-06-27 08:48:20 +02:00
35ce551c8f
* Add build page; correct proxy info; fix Caddy example * Improve Caddyfile example * Apply review comments; add polylith Caddyfile
126 lines
5.7 KiB
Markdown
126 lines
5.7 KiB
Markdown
---
|
|
title: Setting up the domain
|
|
parent: Installation
|
|
nav_order: 2
|
|
permalink: /installation/domainname
|
|
---
|
|
|
|
# Setting up the domain
|
|
|
|
Every Matrix server deployment requires a server name which uniquely identifies it. For
|
|
example, if you are using the server name `example.com`, then your users will have usernames
|
|
that take the format `@user:example.com`.
|
|
|
|
For federation to work, the server name must be resolvable by other homeservers on the internet
|
|
— that is, the domain must be registered and properly configured with the relevant DNS records.
|
|
|
|
Matrix servers usually discover each other when federating using the following methods:
|
|
|
|
1. If a well-known delegation exists on `example.com`, use the domain and port from the
|
|
well-known file to connect to the remote homeserver;
|
|
2. If a DNS SRV delegation exists on `example.com`, use the IP address and port from the DNS SRV
|
|
record to connect to the remote homeserver;
|
|
3. If neither well-known or DNS SRV delegation are configured, attempt to connect to the remote
|
|
homeserver by connecting to `example.com` port TCP/8448 using HTTPS.
|
|
|
|
The exact details of how server name resolution works can be found in
|
|
[the spec](https://spec.matrix.org/v1.3/server-server-api/#resolving-server-names).
|
|
|
|
## TLS certificates
|
|
|
|
Matrix federation requires that valid TLS certificates are present on the domain. You must
|
|
obtain certificates from a publicly-trusted certificate authority (CA). [Let's Encrypt](https://letsencrypt.org)
|
|
is a popular choice of CA because the certificates are publicly-trusted, free, and automated
|
|
via the ACME protocol. (Self-signed certificates are not suitable for federation and will typically
|
|
not be accepted by other homeservers.)
|
|
|
|
Automating the renewal of TLS certificates is best practice. There are many tools for this,
|
|
but the simplest way to achieve TLS automation is to have your reverse proxy do it for you.
|
|
[Caddy](https://caddyserver.com) is recommended as a production-grade reverse proxy with
|
|
automatic TLS which is commonly used in front of Dendrite. It obtains and renews TLS certificates
|
|
automatically and by default as long as your domain name is pointed at your server first.
|
|
Although the finer details of [configuring Caddy](https://caddyserver.com/docs/) is not described
|
|
here, in general, you must reverse proxy all `/_matrix` paths to your Dendrite server. For example,
|
|
with Caddy:
|
|
|
|
```
|
|
reverse_proxy /_matrix/* localhost:8008
|
|
```
|
|
|
|
It is possible for the reverse proxy to listen on the standard HTTPS port TCP/443 so long as your
|
|
domain delegation is configured to point to port TCP/443.
|
|
|
|
## Delegation
|
|
|
|
Delegation allows you to specify the server name and port that your Dendrite installation is
|
|
reachable at, or to host the Dendrite server at a different server name to the domain that
|
|
is being delegated.
|
|
|
|
For example, if your Dendrite installation is actually reachable at `matrix.example.com` port 8448,
|
|
you will be able to delegate from `example.com` to `matrix.example.com` so that your users will have
|
|
`@user:example.com` user names instead of `@user:matrix.example.com` usernames.
|
|
|
|
Delegation can be performed in one of two ways:
|
|
|
|
* **Well-known delegation (preferred)**: A well-known text file is served over HTTPS on the domain
|
|
name that you want to use, pointing to your server on `matrix.example.com` port 8448;
|
|
* **DNS SRV delegation (not recommended)**: See the SRV delegation section below for details.
|
|
|
|
If you are using a reverse proxy to forward `/_matrix` to Dendrite, your well-known or delegation
|
|
must refer to the hostname and port that the reverse proxy is listening on instead.
|
|
|
|
## Well-known delegation
|
|
|
|
Using well-known delegation requires that you are running a web server at `example.com` which
|
|
is listening on the standard HTTPS port TCP/443.
|
|
|
|
Assuming that your Dendrite installation is listening for HTTPS connections at `matrix.example.com`
|
|
on port 8448, the delegation file must be served at `https://example.com/.well-known/matrix/server`
|
|
and contain the following JSON document:
|
|
|
|
```json
|
|
{
|
|
"m.server": "matrix.example.com:8448"
|
|
}
|
|
```
|
|
|
|
For example, this can be done with the following Caddy config:
|
|
|
|
```
|
|
handle /.well-known/matrix/client {
|
|
header Content-Type application/json
|
|
header Access-Control-Allow-Origin *
|
|
respond `{"m.homeserver": {"base_url": "https://matrix.example.com:8448"}}`
|
|
}
|
|
```
|
|
|
|
You can also serve `.well-known` with Dendrite itself by setting the `well_known_server_name` config
|
|
option to the value you want for `m.server`. This is primarily useful if Dendrite is exposed on
|
|
`example.com:443` and you don't want to set up a separate webserver just for serving the `.well-known`
|
|
file.
|
|
|
|
```yaml
|
|
global:
|
|
...
|
|
well_known_server_name: "example.com:443"
|
|
```
|
|
|
|
## DNS SRV delegation
|
|
|
|
This method is not recommended, as the behavior of SRV records in Matrix is rather unintuitive:
|
|
SRV records will only change the IP address and port that other servers connect to, they won't
|
|
affect the domain name. In technical terms, the `Host` header and TLS SNI of federation requests
|
|
will still be `example.com` even if the SRV record points at `matrix.example.com`.
|
|
|
|
In practice, this means that the server must be configured with valid TLS certificates for
|
|
`example.com`, rather than `matrix.example.com` as one might intuitively expect. If there's a
|
|
reverse proxy in between, the proxy configuration must be written as if it's `example.com`, as the
|
|
proxy will never see the name `matrix.example.com` in incoming requests.
|
|
|
|
This behavior also means that if `example.com` and `matrix.example.com` point at the same IP
|
|
address, there is no reason to have a SRV record pointing at `matrix.example.com`. It can still
|
|
be used to change the port number, but it won't do anything else.
|
|
|
|
If you understand how SRV records work and still want to use them, the service name is `_matrix` and
|
|
the protocol is `_tcp`.
|