Aleix Conchillo Flaqué <aconchillo@gmail.com> writes:

>> Using INADDR_ANY instead of INADDR_LOOPBACK makes it convenient when
>> starting the web server inside containers without the need to having to
>> specify INADDR_ANY all the time. This is the default in most libraries
>> and languages.

I may be an outlier, but I don't think we should optimize for
containers.  I think that by default, most things that can reasonably
just listen on localhost should and those that want wider scope can
configure them (which should be easy and apparently is).

It seems this was an earlier conscious choice, from reading the patched docs.

>> This doesn't break backwards compatibility since INADDR_LOOPBACK is also
>> included in INADDR_ANY.

It does break compat because the previous way had a security property
that this one doesn't.  This is fundamentally a disagreement about what
"works" means.  Some people think works primarily means "when I click X
I see Y" and others thinks works primarily means "security properties
(that nothing bad happens" are upheld".