GNOME captive portal helper (was Re: F23 System Wide Change: Default Local DNS Resolver)

[Michael Catanzaro]

On Sat, 2015-06-13 at 14:36 -0400, Paul Wouters wrote:
> using www.gnome.org is wrong. For one, you cannot guarantee they 
> won't
> end up using some redirect and than the captive portal would fail.

I don't get it: what is wrong, what would fail? We expect them to
replace the contents of 
www.gnome.org with either their own content, or else a redirect
someplace else.

> Second, the TTL for that DNS entry is not 0, so it will get cached 
> and
> cause wrong probe results later on.
> 
> There is a good reason we started hotspot-nocache.fedoraproject.org.

Hm... the captive portal helper loads www.gnome.org but it only runs
after NetworkManager has decided there is a captive portal. We can make
this URL configurable at build time if there's really a problem, but
I'm not sure there is, since it's not used for NetworkManager's
connectivity check (which is what triggers us to start the captive
portal helper, and what decides that we have full Internet access and
closes it). For the connectivity check, NetworkManager uses 
https://fedoraproject.org/static/hotspot.txt defined in
/etc/NetworkManager/conf.d/20-connectivity-fedora.conf. So... I guess
that is not good, and we should switch that to use hotspot
-nocache.fedoraproject.org instead?