synapse/docs/reverse_proxy.md

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# 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),
[HAProxy](https://www.haproxy.org/) or
[relayd](https://man.openbsd.org/relayd.8) 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
[Delegation](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.
## Homeserver Configuration
The HTTP configuration will need to be updated for Synapse to correctly record
client IP addresses and generate redirect URLs while behind a reverse proxy.
In `homeserver.yaml` set `x_forwarded: true` in the port 8008 section and
consider setting `bind_addresses: ['127.0.0.1']` so that the server only
listens to traffic on localhost. (Do not change `bind_addresses` to `127.0.0.1`
when using a containerized Synapse, as that will prevent it from responding
to proxied traffic.)
## Reverse-proxy configuration examples
**NOTE**: You only need one of these.
### nginx
```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) {
# note: do not add a path (even a single /) after the port in `proxy_pass`,
# otherwise nginx will canonicalise the URI and cause signature verification
# errors.
proxy_pass http://localhost:8008;
proxy_set_header X-Forwarded-For $remote_addr;
proxy_set_header X-Forwarded-Proto $scheme;
proxy_set_header Host $host;
# 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;
}
}
```
### Caddy v1
```
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 v2
```
matrix.example.com {
reverse_proxy /_matrix/* http://localhost:8008
reverse_proxy /_synapse/client/* http://localhost:8008
}
example.com:8448 {
reverse_proxy http://localhost:8008
}
```
[Delegation](delegate.md) example:
```
(matrix-well-known-header) {
# Headers
header Access-Control-Allow-Origin "*"
header Access-Control-Allow-Methods "GET, POST, PUT, DELETE, OPTIONS"
header Access-Control-Allow-Headers "Origin, X-Requested-With, Content-Type, Accept, Authorization"
header Content-Type "application/json"
}
example.com {
handle /.well-known/matrix/server {
import matrix-well-known-header
respond `{"m.server":"matrix.example.com:443"}`
}
handle /.well-known/matrix/client {
import matrix-well-known-header
respond `{"m.homeserver":{"base_url":"https://matrix.example.com"},"m.identity_server":{"base_url":"https://identity.example.com"}}`
}
}
matrix.example.com {
reverse_proxy /_matrix/* http://localhost:8008
reverse_proxy /_synapse/client/* http://localhost:8008
}
```
### Apache
```apache
<VirtualHost *:443>
SSLEngine on
ServerName matrix.example.com
RequestHeader set "X-Forwarded-Proto" expr=%{REQUEST_SCHEME}
AllowEncodedSlashes NoDecode
ProxyPreserveHost on
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:
```apache
<IfModule security2_module>
SecRuleEngine off
</IfModule>
```
**NOTE 3**: Missing `ProxyPreserveHost on` can lead to a redirect loop.
### HAProxy
```
frontend https
bind *:443,[::]:443 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 matrix.example.com:443
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,[::]:8448 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
```
### Relayd
```
table <webserver> { 127.0.0.1 }
table <matrixserver> { 127.0.0.1 }
http protocol "https" {
tls { no tlsv1.0, ciphers "HIGH" }
tls keypair "example.com"
match header set "X-Forwarded-For" value "$REMOTE_ADDR"
match header set "X-Forwarded-Proto" value "https"
# set CORS header for .well-known/matrix/server, .well-known/matrix/client
# httpd does not support setting headers, so do it here
match request path "/.well-known/matrix/*" tag "matrix-cors"
match response tagged "matrix-cors" header set "Access-Control-Allow-Origin" value "*"
pass quick path "/_matrix/*" forward to <matrixserver>
pass quick path "/_synapse/client/*" forward to <matrixserver>
# pass on non-matrix traffic to webserver
pass forward to <webserver>
}
relay "https_traffic" {
listen on egress port 443 tls
protocol "https"
forward to <matrixserver> port 8008 check tcp
forward to <webserver> port 8080 check tcp
}
http protocol "matrix" {
tls { no tlsv1.0, ciphers "HIGH" }
tls keypair "example.com"
block
pass quick path "/_matrix/*" forward to <matrixserver>
pass quick path "/_synapse/client/*" forward to <matrixserver>
}
relay "matrix_federation" {
listen on egress port 8448 tls
protocol "matrix"
forward to <matrixserver> port 8008 check tcp
}
```
## 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.