Reverse Proxy Configuration

[tairabiteru]

Hello all,

I spent the past few days troubleshooting an issue with my MA configuration. Looking on Discord and online, I found little information about my specific problem, and wound up finding the solution to it myself, though I don't quite understand why it works...only that it does. I want to ask about it here partly because I'm the curious type and like to understand things, but mainly in hopes that someone with the same problem may come across this while troubleshooting.

My setup is behind an Apache2 reverse proxy, so when I configured MA for this, I went to System > Webserver > Base URL and filled in the domain I use to access it. I then went to System > Streams > Published IP Address and did the same. I then restarted MA just to make sure all the settings were loaded.

But I found that when I logged in to MA, the web player was not showing up. Looking at the server logs, I found the following error in the console:

aiohttp.client_exceptions.ClientConnectorError: Cannot connect to host 127.0.0.1:8927 ssl:default [Connect call failed ('127.0.0.1', 8927)]

Looking up above it, I also found this error:

2026-04-21 14:58:23.279 ERROR (MainThread) [aiosendspin.server.server] Failed to start server on 0.0.0.0:8927: illegal IP address string passed to inet_pton

I know now, that the last step - that is, setting the Published IP Address - is what causes the issue, and that setting that to the local IP of the machine rather than the domain makes both of those errors go away, and restores the web player's functionality. But I remain unsure as to exactly why this happens. It makes sense to me that if the Sendspin server fails to start, an attempt to connect from the browser end would result in that error. It even makes sense to me that the call to inet_pton fails, as if the IP passed is indeed 0.0.0.0:8927, it's my understanding that the port number should not be included in the address for that function. But why then, would setting the IP there instead of the domain fix it?

I appreciate any insight into this. I think MA is quite literally the greatest thing Open Home has created since HA. I want to be able to understand it more.

[cookesan]

Base URL and Published IP Address are used for different things.

The webserver Base URL is the public URL for the web UI/API and is the right place for your reverse-proxy domain. The Sendspin provider, however, starts its server on port 8927 with:

host=self.mass.streams.bind_ip
advertise_addresses=[self.mass.streams.publish_ip]

That publish_ip is passed as an advertised address to the Sendspin server, so it needs to be an IP address clients can use, not a DNS name or URL. If you put the domain there, the lower-level sendspin server eventually tries to treat it as an IP address and inet_pton rejects it. Setting it to the local/LAN IP fixes that because it is now a real IP address to advertise.

So keep the reverse-proxy domain in Webserver -> Base URL, and set Streams -> Published IP Address to the machine/container host IP that Sendspin clients should connect to.

[tairabiteru]

Thanks for your explanation. I may be unknowingly venturing into a rabbit hole here, but...why does the advertised IP address have to be an IP address? I know why it fails with inet_pton, that makes sense, but why couldn't a client use DNS instead?

I guess the way I'm seeing it (which is probably incorrect) is that the advertised IP is the one a client (such as a web player in the browser) will use to connect to Sendspin for playback. So it made sense to me that the advertised IP at the very least can't be a local address in this environment, because the web client is not necessarily on the local network. Clearly, that's wrong. But then how does this work? Because as far as I know, I've not forwarded port 8927 at all, so it in theory should not be accessible from outside of my network. And yet if Sendspin is operating the way I think it is, traffic must be getting through somehow...

Again, thanks for your time explaining.

[virtualdxs]

I've hit this same issue. Why can't Sendspin clients use DNS? If I set this to an internal IP, my external devices can't reach it. If I set it to an external IP, it breaks whenever my IP changes. DNS was built specifically to solve this problem.