Consider adding support for Synapse 0.34 backwards-compatibility SRV records

[richvdh]

Some people are using SRV records on their matrix domain as well as having a .well-known which delegates to a different domain, for compatibility with Synapse-pre-0.99, and have reported (#34) finding it confusing that the federation tester ignores that SRV record.

Maybe we could re-run the checks in a Synapse-0.34-compatibility mode?

[olmari]

I agree current behaviour is kind of annoying and in some sense even misleading, as SRV and .well-known is generally considered "compliments" of each others, SRV for older stuff and .well-known for newer stuff... Add .well-known to system that has SRV already and suddenly the SRV is expected to be found where .well-known points, not to "root-domain" server..

In general this feels even more odd behaviour for "how things are supposed to work" as .well-known already should point to server and port, similar to SRV done in "old way".. .well-known and then SRV from that server address doesn't add anything to the mix AFAIK, exept all these config oddities...

[richvdh]

@olmari I'm afraid I don't understand your second paragraph, but:

Add .well-known to system that has SRV already and suddenly the SRV is expected to be found where .well-known points, not to "root-domain" server..

This is a matter for the spec: the federation tester just follows what the spec says. If you think it's wrong, the place to discuss it is the #matrix-spec:matrix.org room or https://github.com/matrix-org/matrix-doc/issues, but given it was discussed in great detail in MSC1708, I don't think there will be much appetite for reopening the conversation.

[adrubesh]

Hello,

I believe I am experiencing this issue and would like to discuss how this is handled. From my understanding and based on https://github.com/matrix-org/synapse/blob/master/docs/federate.md both the .well-known delegration and DNS SRV records should be accepted. For instance, my server name is myservername.com however the synapse server is actually hosted at synapse.myservername.com.

I have a DNS SRV record created to specify this: _matrix._tcp.myservername.com 299 IN SRV 10 5 443 synapse.myservername.com however the federation checker say's it's failed to verify EVEN THOUGH it pulls back the correct SRV record.

[richvdh]

@adrubesh this issue is specifically about the idea of adding a mode to the federation tester which would support the old style of federation delegation where no .well-known lookup is performed. SRV records are correctly supported by the federation tester as it stands. It's more likely that you have a different problem; I suggest checking the documentation about TLS certificates, and if you still don't understand the failure, seek help in #synapse:matrix.org.

[richvdh]

Given that we've got this far without a backwards-compatibility mode, I don't think there's much point in adding one now. Accordingly, I'm going to close this issue.