This rewrote the current implementation to actually use pypi's xml-rpc api which allows
to be incremental. It also allows to fetch the last release date per package. This last
part actually make it possible to update the "last_update" entry in the ListedOrigin
model.

Related to T3399

See inline comment as to why.
This change also adds a Mercurial repo to the test data.

I previously forgot to add the `https://` prefix to the cloning URL.
Whoops.

This is a temporary workaround the time we make a first pass on those repositories.

Related to T3350

Related to [1]

[1] https://sentry.softwareheritage.org/share/issue/afe7279f9f2d4bdc86f4b1b068a281a5/

Since this lister is doing a lot more requests than most other, it makes
sense that issues would arise more often. We want the lister to continue
even if the website is having issues and not break on the first 500 or
closed connection it encounters.

This change introduces a mechanism to retry all exceptions worth
retrying and uses it for the SourceForge lister. Other listers might
benefit from this, but this is out of scope here.

Tests had to be adjusted to stub the sleep function since retries happened
way more often.

tuleap-lister: fix args in test_task.

tuleap-lister: Add rate-limiting test + fix debug and typo.

tuleap-lister: code review: fix mocker + tests/setup_cli.

tuleap-lister: code review: fix relister > lister.

tuleap-lister: code review: fix test_task kwargs.

tuleap-lister: code review: Remove authentication useless lines + fix typos.

tuleap-lister: code review: improve results_simplified for svn repos.

tuleap-lister: code review: add name to CONTRIBUTORS file.

tuleap-lister: code review: Update tutorial for misc files to edit.

tuleap-lister: code review: Update copyright to 2021 exactly.

tuleap-lister: code review: Update py files perms -X.

tuleap-lister: code review: minimise json files.

tuleap-lister: code review: fix chmod on json files.

tuleap-lister: code review: fix var names + add tests.

tuleap-lister: code review: fix useless indirection.

tuleap-lister: code review: Add empty repo test, minor typo fixes.

It's suboptimal to say the least to stop the entire lister process
if a single project page is somehow broken (404, most likely). This
change logs the issue as a warning and carries on, as well as some
minor logging changes and comments touch ups.

Related to T3310

The credentials parameter is not optional due to the instance constructor logic. Even if
unused, this must be provided to the lister (from the task standpoint).

Related to T3310#64801

This ensures the mocked sleep will work with all tenacity versions.

Related to T3310

It fixes debian package build of swh-lister on buster.

SourceForge's sitemaps (1 main one + many sharded) give us a "last
modified" date for every subsitemap and project, allowing us to perform
an incremental listing.

We store the subsitemaps' "last modified" dates in the lister state, as
well as those of the empty projects (projects which don't have any VCS
registered), and the rest comes from the already visited origins from
the database.

The tests try to cover the possible cases of a subsitemap that has
changed, one that hasn't, a project that has change, one that hasn't,
and same for an empty project.

Enable to check package documentation can be built without producing
sphinx warnings.

The sphinx environment is designed to be used in continuous integration
in order to prevent breaking documentation build when committing changes.

The sphinx-dev environment is designed to be used inside a full swh
development environment.

Related to T3258

Bitbucket's API kind of supports REST workflows, but the clearly use it
like an RPC API (the hardcoded schema in `PROJECT_API_URL_FORMAT`
make it particularly clear)

Sphinx complains because it's an orphan document.

Following zack's work on T735, this change introduces an actual SWH lister for
SourceForge.

SourceForge provides a main sitemap that lists sharded sitemaps, which
themselves list pages. Each page belongs to a project (or sub-project,
though those are rare), information about which can be found by querying
a REST API, which gives us the list of any and all VCS used for said
project. Both sitemaps and pages have a "last modified" timestamp that
will be used in a future patch to implement incremental listing.

More precise information can be found as inline comments or docstrings.

These errors happen, sometimes, when requesting large pages of results.

This makes the logic easier to test.

These happen, sometimes, when the connection to the GitHub server
resets, e.g. because of congestion on a slow link.

This will help us to break the retry logic for the listing requests
themselves to a separate function too.

Tenma authored 4 years ago and Antoine R. Dumont committed 4 years ago

This adds a new tutorial which details how to currently write the new listers (both
incremental or stateless). This proposes a python template file to start a new lister.

At last, this renames the previous tutorial into tutorial-2017.

Related to T3073

Some distributions (e.g. debian-security) have a slightly different URL
for retrieving source packages metadata.

So add a new URL template to process when trying to download such data.

Related to T3032#58239

Remove outdated part about listers database and use swh CLI in
README for executing a lister instead of raw Python code.

A CRAN package can appear twice in the JSON list returned by the
list_all_packages.R script, most recent version of the package
appearing first.

So handle that edge case to avoid error when sending origins to
the scheduler.

xmltodict now raises an error while trying to parse the HTML content
of https://pypi.org/simple/ page.

So use BeautifulSoup HTML parser instead as it is aleady a requirement
of swh-lister and it does not fail parsing the PyPI HTML page.

Also drop no longer used xmltodict in requirements.

Legacy Lister classes from the swh.lister.core mdule are no longer
used in swh-lister codebase so it is time to remove them.

Also remove lister CLI options related to legacy Lister API.

As a consequence, the following requirements are no longer needed:
arrow, SQLAlchemy, sqlalchemy-stubs and testing.postgresql.

Closes T2442