From 8ee0d745169fa12fd116692a9484930bd7b38167 Mon Sep 17 00:00:00 2001 From: Brendan Abolivier Date: Tue, 18 Feb 2020 12:05:45 +0000 Subject: [PATCH] Split the delegating documentation out of federate.md and trim it down --- docs/delegate.md | 87 +++++++++++++++++++++++++++++++ docs/federate.md | 133 ----------------------------------------------- 2 files changed, 87 insertions(+), 133 deletions(-) create mode 100644 docs/delegate.md diff --git a/docs/delegate.md b/docs/delegate.md new file mode 100644 index 0000000000..4126fffe71 --- /dev/null +++ b/docs/delegate.md @@ -0,0 +1,87 @@ +# Delegation + +For a more flexible configuration, you can have `server_name` +resources (eg: `@user:example.com`) served by a different host and +port (eg: `synapse.example.com:443`). + +Without configuring delegation, the matrix federation will +expect to find your server via `example.com:8448`. The following methods +allow you retain a `server_name` of `example.com` so that your user IDs, room +aliases, etc continue to look like `*:example.com`, whilst having your +federation traffic routed to a different server (e.g. `synapse.example.com`). + +## .well-known delegation + +To use this method, you need to be able to alter the +`server_name` 's https server to serve the `/.well-known/matrix/server` +URL. Having an active server (with a valid TLS certificate) serving your +`server_name` domain is out of the scope of this documentation. + +The URL `https:///.well-known/matrix/server` should +return a JSON structure containing the key `m.server` like so: + +```json +{ + "m.server": "[:]" +} +``` + +In our example, this would mean that URL `https://example.com/.well-known/matrix/server` +should return: + +```json +{ + "m.server": "synapse.example.com:443" +} +``` + +Note, specifying a port is optional. If no port is specified, then it defaults +to 8448. + +Most installations will not need to configure .well-known. However, it can be +useful in cases where the admin is hosting on behalf of someone else and +therefore cannot gain access to the necessary certificate. With .well-known, +federation servers will check for a valid TLS certificate for the delegated +hostname (in our example: `synapse.example.com`). + +## Delegation FAQ + +### When do I need delegation? + +If your homeserver's APIs are accessible on the default federation port (8448) +and the domain your `server_name` points to, you do not need any delegation. + +For instance, if you registered `example.com` and pointed its DNS A record at a +fresh server, you could install Synapse on that host, giving it a `server_name` +of `example.com`, and once a reverse proxy has been set up to proxy all requests +sent to the port `8448` and serve TLS certificates for `example.com`, you +wouldn't need any delegation set up. + +**However**, if your homeserver's APIs aren't accessible on port 8448 and on the +domain `server_name` points to, you will need to let other servers know how to +find it using delegation. + +### Do you still recommend against using a reverse proxy on the federation port? + +We no longer actively recommend against using a reverse proxy. Many admins will +find it easier to direct federation traffic to a reverse proxy and manage their +own TLS certificates, and this is a supported configuration. + +See [reverse_proxy.md](reverse_proxy.md) for information on setting up a +reverse proxy. + +### Do I still need to give my TLS certificates to Synapse if I am using a reverse proxy? + +This is no longer necessary. If you are using a reverse proxy for all of your +TLS traffic, then you can set `no_tls: True` in the Synapse config. + +In that case, the only reason Synapse needs the certificate is to populate a legacy +`tls_fingerprints` field in the federation API. This is ignored by Synapse 0.99.0 +and later, and the only time pre-0.99 Synapses will check it is when attempting to +fetch the server keys - and generally this is delegated via `matrix.org`, which +is running a modern version of Synapse. + +### Do I need the same certificate for the client and federation port? + +No. There is nothing stopping you from using different certificates, +particularly if you are using a reverse proxy. \ No newline at end of file diff --git a/docs/federate.md b/docs/federate.md index f9f17fcca5..8552927225 100644 --- a/docs/federate.md +++ b/docs/federate.md @@ -18,139 +18,6 @@ Once federation has been configured, you should be able to join a room over federation. A good place to start is ``#synapse:matrix.org`` - a room for Synapse admins. - -## Delegation - -For a more flexible configuration, you can have ``server_name`` -resources (eg: ``@user:example.com``) served by a different host and -port (eg: ``synapse.example.com:443``). There are two ways to do this: - -- adding a ``/.well-known/matrix/server`` URL served on ``https://example.com``. -- adding a DNS ``SRV`` record in the DNS zone of domain - ``example.com``. - -Without configuring delegation, the matrix federation will -expect to find your server via ``example.com:8448``. The following methods -allow you retain a `server_name` of `example.com` so that your user IDs, room -aliases, etc continue to look like `*:example.com`, whilst having your -federation traffic routed to a different server. - -### .well-known delegation - -To use this method, you need to be able to alter the -``server_name`` 's https server to serve the ``/.well-known/matrix/server`` -URL. Having an active server (with a valid TLS certificate) serving your -``server_name`` domain is out of the scope of this documentation. - -The URL ``https:///.well-known/matrix/server`` should -return a JSON structure containing the key ``m.server`` like so: - - { - "m.server": "[:]" - } - -In our example, this would mean that URL ``https://example.com/.well-known/matrix/server`` -should return: - - { - "m.server": "synapse.example.com:443" - } - -Note, specifying a port is optional. If a port is not specified an SRV lookup -is performed, as described below. If the target of the -delegation does not have an SRV record, then the port defaults to 8448. - -Most installations will not need to configure .well-known. However, it can be -useful in cases where the admin is hosting on behalf of someone else and -therefore cannot gain access to the necessary certificate. With .well-known, -federation servers will check for a valid TLS certificate for the delegated -hostname (in our example: ``synapse.example.com``). - -### DNS SRV delegation - -To use this delegation method, you need to have write access to your -``server_name`` 's domain zone DNS records (in our example it would be -``example.com`` DNS zone). - -This method requires the target server to provide a -valid TLS certificate for the original ``server_name``. - -You need to add a SRV record in your ``server_name`` 's DNS zone with -this format: - - _matrix._tcp. IN SRV - -In our example, we would need to add this SRV record in the -``example.com`` DNS zone: - - _matrix._tcp.example.com. 3600 IN SRV 10 5 443 synapse.example.com. - -Once done and set up, you can check the DNS record with ``dig -t srv -_matrix._tcp.``. In our example, we would expect this: - - $ dig -t srv _matrix._tcp.example.com - _matrix._tcp.example.com. 3600 IN SRV 10 0 443 synapse.example.com. - -Note that the target of a SRV record cannot be an alias (CNAME record): it has to point -directly to the server hosting the synapse instance. - -### Delegation FAQ -#### When do I need a SRV record or .well-known URI? - -If your homeserver listens on the default federation port (8448), and your -`server_name` points to the host that your homeserver runs on, you do not need an SRV -record or `.well-known/matrix/server` URI. - -For instance, if you registered `example.com` and pointed its DNS A record at a -fresh server, you could install Synapse on that host, -giving it a `server_name` of `example.com`, and once [ACME](acme.md) support is enabled, -it would automatically generate a valid TLS certificate for you via Let's Encrypt -and no SRV record or .well-known URI would be needed. - -**However**, if your server does not listen on port 8448, or if your `server_name` -does not point to the host that your homeserver runs on, you will need to let -other servers know how to find it. The way to do this is via .well-known or an -SRV record. - -#### I have created a .well-known URI. Do I also need an SRV record? - -No. You can use either `.well-known` delegation or use an SRV record for delegation. You -do not need to use both to delegate to the same location. - -#### Can I manage my own certificates rather than having Synapse renew certificates itself? - -Yes, you are welcome to manage your certificates yourself. Synapse will only -attempt to obtain certificates from Let's Encrypt if you configure it to do -so.The only requirement is that there is a valid TLS cert present for -federation end points. - -#### Do you still recommend against using a reverse proxy on the federation port? - -We no longer actively recommend against using a reverse proxy. Many admins will -find it easier to direct federation traffic to a reverse proxy and manage their -own TLS certificates, and this is a supported configuration. - -See [reverse_proxy.md](reverse_proxy.md) for information on setting up a -reverse proxy. - -#### Do I still need to give my TLS certificates to Synapse if I am using a reverse proxy? - -Practically speaking, this is no longer necessary. - -If you are using a reverse proxy for all of your TLS traffic, then you can set -`no_tls: True` in the Synapse config. In that case, the only reason Synapse -needs the certificate is to populate a legacy `tls_fingerprints` field in the -federation API. This is ignored by Synapse 0.99.0 and later, and the only time -pre-0.99 Synapses will check it is when attempting to fetch the server keys - -and generally this is delegated via `matrix.org`, which will be running a modern -version of Synapse. - -#### Do I need the same certificate for the client and federation port? - -No. There is nothing stopping you from using different certificates, -particularly if you are using a reverse proxy. However, Synapse will use the -same certificate on any ports where TLS is configured. - ## Troubleshooting You can use the [federation tester](