[tz] Data loss on FTP Server

[Paul.Koning at dell.com]

> On Oct 24, 2017, at 8:38 PM, Kim Davies <kim.davies at iana.org> wrote:
> 
> Quoting Zefram on Tuesday October 24, 2017:
>> 
>> HTTPS is fine for retrieving a specific release, but FTP offers a couple
>> of other facilities that AFAICS HTTPS doesn't provide.  Specifically, by
>> FTP I can enumerate old releases (NLST on the /tz/releases directory), and
>> I can identify the latest release (by processing the directory listing).
>> I've automated those jobs.  Is there a recommended way to do these things
>> through the HTTPS interface?  (Scraping a human-oriented web page isn't
>> an attractive approach.)
> 
> I'm happy to explore providing additional metadata in a structured way
> if that is useful. There is currently some metadata on the current
> version that is not currently exposed but could be.
> 
> Is retrieving old versions of the tzdb a common use case?

Not for me.  The reason I use FTP is that I can find the latest file name, so I can track which revision it is.  That information exists, I suppose, in the NEWS file but that's in human form, not program-friendly form.

A metadata file would be great.  XML might be a good format.  The minimal content would be, I think, version string (e.g. "2017c") and release date.  I can imagine other information that might be attractive, for example the names of countries affected (separate for "future" and "past" timestamps), and perhaps the dates affected (for future, that would be the effective date of the new or changed rule).

	paul