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Remove outdated part about listers database and use swh CLI in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

The previous implementation was generating tasks for a non implemented
Packagist loader.

The new implementation extracts source repository URL, VCS type and
last update date for each package referenced by Packagist and send
those info to the scheduler.

Packages metadata are retrieved using Packagist API endpoints whose
responses are served from static files, which are guaranteed to be
efficient on the Packagist side (no dymamic queries).
Furthermore, subsequent listing will send the "If-Modified-Since" HTTP
header to only retrieve packages metadata updated since the previous
listing operation in order to save bandwidth and return only origins
which might have new released versions.

Closes T2991

UTC timezone settings can be obtained from the datetime.timezone
module from Python standard library so remove dependency on external
pytz module.

Ensure the behavior is the same when a base url is provided or not

Related to T3013#57810

Listers like github and bitbucket should not be impacted as they already list 1000
records per page.

This adds a second behavior to the cgit lister to actually compute origin urls instead
of parsing them out of another http request on git detailed page.

This new behavior is expected to be the default behavior.

The old behavior is kept for now and is expected to be used as fallback if too much
false negatives are returned.

Related to T2999

ISO functionalities port of the stateless GNU lister to the new
swh.lister.pattern.Lister API.

Closes T2990

This generates an error due to the datetime type field, so manually build
the dict instead.

Related to T3003#57551

launchpadlib can list the last modified repository twice so ensure to yield
a single ListedOrigin model for that special case.

Related to T3003#57551

In effect, it just allows to add credentials to cgit, cran and pypi listers.

This fixes instances of error [1]

[1] https://sentry.softwareheritage.org/share/issue/a5fb50f8e43e4b328c4917771576c6b0/

Related to T2998

An exception is raised when registering task types in scheduler database otherwise.

As origins is a generator, the previous behavior would try to consume the overall
generator to send the records.

This groups and sends batch of 100 origins to the scheduler for writing.

Related to T3003

Port launchpad lister to the swh.lister.pattern.Lister API.

Last update date of each listed git repositories is now sent to the scheduler.

The lister can work in incremental mode, only modified repositories since
the last listing operation will be returned in that case.

Closes T2992

In effect, it just allows to add credentials to cgit, cran and pypi listers.

This fixes instances of error [1]

[1] https://sentry.softwareheritage.org/share/issue/2c35a9f129cf4982a2dd003a232d507a/

Related to T2998

This fixes the master build [1]

[1] https://jenkins.softwareheritage.org/job/DLS/job/tests/1210/console

while allowing legacy lister to still run (with --legacy)

Drop launchpad lister from the lister to check, its test setup is more involved than the
other listers. As its setup is not done in that test, it's actually connecting
anonymously to the launchpad server. So remove such lister from the test.

This should also fix the debian build which refuses such access [1]

[1] https://jenkins.softwareheritage.org/job/debian/job/packages/job/DLS/job/gbp-buildpackage/97/console

This current test was failing in a debian chroot with connection error.

The listers depending on it got ported to the new lister api.

Plus that instruction is not correct in most recent requests_mock version (failing the
debian build)

Related to T2988