fix: Use guessAppRootOr to enable relative root if desired.

[klockeph]

This is useful when serving on 0.0.0.0, such that querying from any other device with : does not fall back to 0.0.0.0:PORT, which fails. (#2099)

Tested: Manually

[simonmichael]

Cool. What's a description of the user-visible difference this makes, suitable for the manual ?

On mac, with or without your fix, running hledger-web with --host 0.0.0.0 or --host localhost seems to break it for web browsers - Safari shows an empty page and Firefox refuses to browse it. (Also one has to use --port to avoid AirTunes which is using port 5000.)

[klockeph]

You mean serving from Mac?
Unfortunately, I cannot test that sorry.

The user-visible change would be that if the web interface is reachable from multiple domains or IPs, they will not necessarily be redirected to the base_url; instead hledger-web will try to keep them at the root/host from the URL of the request.
Apart from this it fixes the bug where 0.0.0.0 would only work for access from localhost.

If this is not desired behavior we could maybe check if base_url is set and if it is, keep ApprootMaster?
I just wasn't sure how the arguments are passed and if base_url will always contain "IP:PORT" if unset.

[simonmichael]

Ah I see - when hledger-web is accessible at multiple IPs, it will keep responding from the same IP address you visited ? That sounds good to me, I guess you have observed it fixing your issue on GNU/linux. I don't know if this interacts with the other options, do you think there might be a problem there needing more testing ? Otherwise I'm happy to merge this. I'll call for testers on chat also.

[klockeph]

Ah I see - when hledger-web is accessible at multiple IPs, it will keep responding from the same IP address you visited ?

Yes exactly that. Plus it would also keep the same hostname, imagine you have the host as "foo" and "192.168.1.123", then visiting http://192.168.1.123:5000 would redirect to http://192.168.1.123:5000/journal and visiting http://foo:5000 would redirect to http://foo:5000/journal.

I guess you have observed it fixing your issue on GNU/linux.

Actually, I tested the change on Windows so far. My Linux Haskell setup is super broken at the moment... :/

I don't know if this interacts with the other options

The only option it could interact with is base_url if I understand correctly.

[klockeph]

Tested on Linux as well now; also works.

[simonmichael]

I think we need to clarify how this interacts with --base-url. The doc for that option says

--base-url=URL : set the base url (default: http://IPADDR:PORT). Note: affects url generation but not route parsing. Can be useful if running behind a reverse web proxy that does path rewriting.

Note to self: translate this to userese.

[klockeph]

We could just let base-url overwrite the guessAppRootOr. So if base-url is given, don't use the guess. Otherwise use guess and fall back to IP:PORT.
However I'm not proficient in Haskell, so if you want to go for this I'd be happy if someone else picks up the patch.

[simonmichael]

I can't fully test this on mac, but I see that we print both the listening address and port and the base url and port, so it should be easy enough to troubleshoot any issues. I will shortly merge this as 6312446, thank you !