Re: jigdo - avoid unneeded .iso rebuild

[Richard Atterer <richard@2006.atterer.net>]

On Mon, Sep 11, 2006 at 06:22:47PM -0500, Carl Karsten wrote:
> I am trying to figure out how to poll a web server and only run the a 
> process (see below) when the .jigdo file has been updated.
> 
> I can get the Last-Modified timestamp from the server, and I can parse the 
> output from wget looking for "Server file no newer than local file" but I 
> am hoping there is a more elegant way.

Well - that already *is* quite elegant. :-)

If you want to be absolutely certain that the image has changed, you need 
to download the .template file and check whether the checksum of the final 
.iso has changed:

jigdo-file list-template --template foo.template | grep ^image-info

But I'm not sure whether it's worth it; the template files are quite big 
for repeated downloads. You could implement this as a second step after the 
server timestamp has caused curl to download the file.

Cheers,

  Richard

-- 
  __   _
  |_) /|  Richard Atterer     |  GnuPG key: 888354F7
  | \/¯|  http://atterer.net  |  08A9 7B7D 3D13 3EF2 3D25  D157 79E6 F6DC 8883 54F7
  ¯ '` ¯