Subject: [apps-discuss] Sunset HTTP header field

From: Erik Wilde <[email-masked]>
Date: Mon, 03 Aug 2015 18:44:01 -0700

hello.

a little while ago there was a brief thread on apps-discuss regarding 
how to expose information about "URI lifetime" in an HTTP response:

https://www.ietf.org/mail-archive/web/apps-discuss/current/msg14343.html

it took me a little while to write something up, but i have just 
published a first draft proposing a "Sunset" HTTP header field, that 
serves that purpose:

https://tools.ietf.org/html/draft-wilde-sunset-header-00

it is as simple as possible right now (a simple timestamp advertising 
when a resource might become unavailable). i'd be very interested in 
some feedback about what else might be needed, and of course in people 
finding this useful and maybe implementing it in their services.

thanks a lot and cheers,

dret.

-- 
erik wilde | mailto:[email-masked]  -  tel:+1-510-2061079 |
            | UC Berkeley  -  School of Information (ISchool) |
            | http://dret.net/netdret http://twitter.com/dret |

---

From: James M Snell <[email-masked]>
Date: Mon, 3 Aug 2015 18:54:48 -0700

This is certainly interesting, but I'm not quite sure it goes far
enough. In general, when a particular API is being deprecated, there
is generally some form of replacement or alternative that developers
are being pushed towards, and potentially some form of notice that
should be displayed.

Considering that, a Link header might be an interesting possible approach:

Link: </deprecation-notice.html>; rel="sunset"; title="This API will
be sunset on 2015-12-12"; sunset=2015-12-12

- James

On Mon, Aug 3, 2015 at 6:44 PM, Erik Wilde <[email-masked]> wrote:
> hello.
>
> a little while ago there was a brief thread on apps-discuss regarding how to
> expose information about "URI lifetime" in an HTTP response:
>
> it took me a little while to write something up, but i have just published a
> first draft proposing a "Sunset" HTTP header field, that serves that
> purpose:
>
> it is as simple as possible right now (a simple timestamp advertising when a
> resource might become unavailable). i'd be very interested in some feedback
> about what else might be needed, and of course in people finding this useful
> and maybe implementing it in their services.
>
> thanks a lot and cheers,
>
> dret.
>
> --
> _______________________________________________
> apps-discuss mailing list
> [email-masked]
> https://www.ietf.org/mailman/listinfo/apps-discuss

---

From: Erik Wilde <[email-masked]>
Date: Mon, 03 Aug 2015 19:06:07 -0700

hello james.

thanks a lot for your feedback!

> are being pushed towards, and potentially some form of notice that

yes, those may be things that people want to advertise in well-known 
ways. i had listed both aspects as open issues:

https://tools.ietf.org/html/draft-wilde-sunset-header-00#section-8

my idea was to add optional qualifiers to the timestamp if people seem 
to want these features, but that's of course just one way of doing it.

> be sunset on 2015-12-12"; sunset=2015-12-12

i was considering the link relation type design option, but then 
concluded that at its core, the sunset timestamp is mostly a "unary 
link" and thus does not fit the link model very well. but i agree that 
pretty much anything can be modeled as links, and then it would fit into 
the link header as shown in your example.

thanks again and cheers,

dret.