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
Prior to this commit, all listers were instantiated at the same time even if
only one was needed. This commit separates those instantiations.
The only drawback to this is the db model initialization which now happens at
each lister instantiation. This can be dealt with if needed at another time
though.
Add a new register-task-types cli that will create missing task-type entries in the
scheduler according to:
- only create missing task-types (do not update them), but check that the
backend_name field is consistent,
- each SWHTask-based task declared in a module listed in the 'task_modules'
plugin registry field will be checked and added if needed; tasks which name
start wit an underscore will not be added,
- added task-type will have:
- the 'type' field is derived from the task's function name (with underscores
replaced with dashes),
- the description field is the first line of that function's docstring,
- default values as provided by the swh.lister.cli.DEFAULT_TASK_TYPE (with
a simple pattern matching to have decent default values for full/incremental
tasks),
- these default values can be overloaded via the 'task_type' plugin registry
entry.
For this, we had to rename all tasks names (eg. `cran_lister` -> `list_cran`).
Comes with some tests.
Listers are declared as plugins via the `swh.workers` entry_point.
As such, the registry function is expected to return a dict with the
`task_modules` field (as for generic worker plugins), plus:
- `lister`: the lister class,
- `models`: list of SQLAlchemy models used by this lister,
- `init` (optionnal): hook (callable) used to initialize the lister's state
(typically, create/initialize the database for this lister).
If not set, the default implementation creates database tables (after
optionally having deleted exisintg ones) according to models declared in
the `models` register field.
There is no need for explicitely add lister task modules in the main
`conftest` module, but any new/extra lister to be tested must be registered
(the tested lister module must be properly installed in the test environment).
Also refactor a bit the cli tools:
- add support for the standard --config-file option at the 'lister' group
level,
- move the --db-url to the 'lister' group,
- drop the --lister option for the `swh lister db-init` cli tool:
initializing (especially with --drop-tables) the database for a single
lister is unreliable, since all tables are created using a sibgle MetaData
(in the same namespace).
Prior to this commit, the policy and priority were hard-coded.
The default values are now the old hard-coded values.
This will allow to develop a cli to trigger forges listing with oneshot policy
and some priority tasks. Thus ingesting those faster and without manual
interventation as we currently do.
