forked-synapse/docs/reverse_proxy.md
Richard van der Hoff d8e95e5452
Add support for X-Forwarded-Proto (#9472)
rewrite XForwardedForRequest to set `isSecure()` based on
`X-Forwarded-Proto`. Also implement `getClientAddress()` while we're here.
2021-02-24 18:11:33 +00:00

186 lines
5.9 KiB
Markdown

# Using a reverse proxy with Synapse
It is recommended to put a reverse proxy such as
[nginx](https://nginx.org/en/docs/http/ngx_http_proxy_module.html),
[Apache](https://httpd.apache.org/docs/current/mod/mod_proxy_http.html),
[Caddy](https://caddyserver.com/docs/quick-starts/reverse-proxy) or
[HAProxy](https://www.haproxy.org/) in front of Synapse. One advantage
of doing so is that it means that you can expose the default https port
(443) to Matrix clients without needing to run Synapse with root
privileges.
You should configure your reverse proxy to forward requests to `/_matrix` or
`/_synapse/client` to Synapse, and have it set the `X-Forwarded-For` and
`X-Forwarded-Proto` request headers.
You should remember that Matrix clients and other Matrix servers do not
necessarily need to connect to your server via the same server name or
port. Indeed, clients will use port 443 by default, whereas servers default to
port 8448. Where these are different, we refer to the 'client port' and the
'federation port'. See [the Matrix
specification](https://matrix.org/docs/spec/server_server/latest#resolving-server-names)
for more details of the algorithm used for federation connections, and
[delegate.md](<delegate.md>) for instructions on setting up delegation.
**NOTE**: Your reverse proxy must not `canonicalise` or `normalise`
the requested URI in any way (for example, by decoding `%xx` escapes).
Beware that Apache *will* canonicalise URIs unless you specify
`nocanon`.
Let's assume that we expect clients to connect to our server at
`https://matrix.example.com`, and other servers to connect at
`https://example.com:8448`. The following sections detail the configuration of
the reverse proxy and the homeserver.
## Reverse-proxy configuration examples
**NOTE**: You only need one of these.
### nginx
```
server {
listen 443 ssl http2;
listen [::]:443 ssl http2;
# For the federation port
listen 8448 ssl http2 default_server;
listen [::]:8448 ssl http2 default_server;
server_name matrix.example.com;
location ~* ^(\/_matrix|\/_synapse\/client) {
proxy_pass http://localhost:8008;
proxy_set_header X-Forwarded-For $remote_addr;
proxy_set_header X-Forwarded-Proto $scheme;
# Nginx by default only allows file uploads up to 1M in size
# Increase client_max_body_size to match max_upload_size defined in homeserver.yaml
client_max_body_size 50M;
}
}
```
**NOTE**: Do not add a path after the port in `proxy_pass`, otherwise nginx will
canonicalise/normalise the URI.
### Caddy 1
```
matrix.example.com {
proxy /_matrix http://localhost:8008 {
transparent
}
proxy /_synapse/client http://localhost:8008 {
transparent
}
}
example.com:8448 {
proxy / http://localhost:8008 {
transparent
}
}
```
### Caddy 2
```
matrix.example.com {
reverse_proxy /_matrix/* http://localhost:8008
reverse_proxy /_synapse/client/* http://localhost:8008
}
example.com:8448 {
reverse_proxy http://localhost:8008
}
```
### Apache
```
<VirtualHost *:443>
SSLEngine on
ServerName matrix.example.com;
RequestHeader set "X-Forwarded-Proto" expr=%{REQUEST_SCHEME}
AllowEncodedSlashes NoDecode
ProxyPass /_matrix http://127.0.0.1:8008/_matrix nocanon
ProxyPassReverse /_matrix http://127.0.0.1:8008/_matrix
ProxyPass /_synapse/client http://127.0.0.1:8008/_synapse/client nocanon
ProxyPassReverse /_synapse/client http://127.0.0.1:8008/_synapse/client
</VirtualHost>
<VirtualHost *:8448>
SSLEngine on
ServerName example.com;
RequestHeader set "X-Forwarded-Proto" expr=%{REQUEST_SCHEME}
AllowEncodedSlashes NoDecode
ProxyPass /_matrix http://127.0.0.1:8008/_matrix nocanon
ProxyPassReverse /_matrix http://127.0.0.1:8008/_matrix
</VirtualHost>
```
**NOTE**: ensure the `nocanon` options are included.
**NOTE 2**: It appears that Synapse is currently incompatible with the ModSecurity module for Apache (`mod_security2`). If you need it enabled for other services on your web server, you can disable it for Synapse's two VirtualHosts by including the following lines before each of the two `</VirtualHost>` above:
```
<IfModule security2_module>
SecRuleEngine off
</IfModule>
```
### HAProxy
```
frontend https
bind :::443 v4v6 ssl crt /etc/ssl/haproxy/ strict-sni alpn h2,http/1.1
http-request set-header X-Forwarded-Proto https if { ssl_fc }
http-request set-header X-Forwarded-Proto http if !{ ssl_fc }
http-request set-header X-Forwarded-For %[src]
# Matrix client traffic
acl matrix-host hdr(host) -i matrix.example.com
acl matrix-path path_beg /_matrix
acl matrix-path path_beg /_synapse/client
use_backend matrix if matrix-host matrix-path
frontend matrix-federation
bind :::8448 v4v6 ssl crt /etc/ssl/haproxy/synapse.pem alpn h2,http/1.1
http-request set-header X-Forwarded-Proto https if { ssl_fc }
http-request set-header X-Forwarded-Proto http if !{ ssl_fc }
http-request set-header X-Forwarded-For %[src]
default_backend matrix
backend matrix
server matrix 127.0.0.1:8008
```
## Homeserver Configuration
You will also want to set `bind_addresses: ['127.0.0.1']` and
`x_forwarded: true` for port 8008 in `homeserver.yaml` to ensure that
client IP addresses are recorded correctly.
Having done so, you can then use `https://matrix.example.com` (instead
of `https://matrix.example.com:8448`) as the "Custom server" when
connecting to Synapse from a client.
## Health check endpoint
Synapse exposes a health check endpoint for use by reverse proxies.
Each configured HTTP listener has a `/health` endpoint which always returns
200 OK (and doesn't get logged).
## Synapse administration endpoints
Endpoints for administering your Synapse instance are placed under
`/_synapse/admin`. These require authentication through an access token of an
admin user. However as access to these endpoints grants the caller a lot of power,
we do not recommend exposing them to the public internet without good reason.