[Bug 253119] Re: PPA packages do not show a changelog in update-manager

[Colin Watson]

I think nowadays it would be sensible to use the Launchpad API for this
via launchpadlib rather than scraping HTML.  For example, something like
this can get a URL from which you can fetch the raw changelog for
version 139 of source package launchpad-buildd in ppa:launchpad/ppa:

  >>> archive = lp.archives.getByReference(reference='ppa:launchpad/ubuntu/ppa')
  >>> spph = archive.getPublishedSources(
  ...     source_name='launchpad-buildd', exact_match=True, version='139')[0]
  >>> changelog_url = spph.changelogUrl()

You have to be using the "devel" API version, but I think that's
reasonable here.

Now, obviously this is very hardcoded and needs more robustness, but it
does the job and is far preferable to HTML scraping.

The main caveat is that this will only work reasonably for public PPAs,
since update-manager will have to use the API anonymously.  As long as
error handling is reasonable, having changelogs only for public PPAs is
still much better than having them for no PPAs at all.

I can see the rationale for actually publishing the changelogs alongside
the .debs directly: it would be much easier for clients.  However, it
would be pretty cumbersome to actually do it in the current
architecture.  We intend eventually to move to "diskless PPAs", where
ppa.launchpad.net would become a caching frontend that fetches
information directly from the database as needed rather than publishing
things as static files, which has various infrastructure-scaling
benefits.  That would make it much easier to do this kind of thing.
Plans for this are still in their infancy, though, and I can't give you
a timescale.  For the moment, I would recommend taking the anonymous-
Launchpad-API approach outlined above in update-manager.

-- 
You received this bug notification because you are a member of Ubuntu
Foundations Bugs, which is subscribed to update-manager in Ubuntu.
https://bugs.launchpad.net/bugs/253119

Title:
  PPA packages do not show a changelog in update-manager

Status in Launchpad itself:
  Triaged
Status in update-manager package in Ubuntu:
  Confirmed

Bug description:
  When installing official packages via update-manager, the change log
  is available from a tab in the GUI (next to description).  These
  change logs are not available for PPA packages.  Could this facility
  be added?  When discussed on IRC #launchpad, there was some concern
  this might blur the boundaries between official and PPA packages and
  result in unfounded trust in the PPA packages.

To manage notifications about this bug go to:
https://bugs.launchpad.net/launchpad/+bug/253119/+subscriptions