Add management command to watch all PURLs

[keshav-space]

• Management command to watch and index latest version of all the PURLs

[pombredanne]

This looks fine, but this is difficult to test as it looks at the whole DB at once.
If you add an option to focus the command on a PURL: this will make it easier to test even if we do not have the models yet.
See also a few minor nits.

[pombredanne]

In a next iteration, you should consider using some groupby and get all versions at once, or have a queryset that gets you the latest version automatically.

But really you likely want the missing versions rather than the latest versions.
It could be a refinement in a next iteration.
The cases I can fathom could be:

1. get all the missing versions
2. get the latest version (but we could have multiple ranges? ... so may be get all the latest versions in each "range"?)
3. get all the newest versions after some version

[pombredanne]

Do we have some history log entry to write in a next iteration?

[JonoYang]

@pombredanne @keshav-space

Given that we mention watching purls, do we want this command to use the purl watch code from #271 ?

[pombredanne]

@pombredanne @keshav-space

Given that we mention watching purls, do we want this command to use the purl watch code from #271 ?

@JonoYang I thought this was the case?

[JonoYang]

@pombredanne @keshav-space
Given that we mention watching purls, do we want this command to use the purl watch code from #271 ?

@JonoYang I thought this was the case?

The logic in the management command looks similar to the function here: https://github.com/nexB/purldb/blob/244-watch-model/packagedb/tasks.py#L26

@keshav-space I'm just wondering if you were going to to update this management command to use the same code from the purl watch PR in #271 or after #271 has been merged

[keshav-space]

@keshav-space I'm just wondering if you were going to to update this management command to use the same code from the purl watch PR in #271 or after #271 has been merged

@JonoYang This management command in it's current implementation will watch all the PURLs irrespective of whether or not the PURL is present in PackageWatch.
We can reuse the code from #271. But before that, we need to decide whether or not this management command should depend on PackageWatch model if it depends on PackageWatch model then this command will not watch all the packages.

[JonoYang]

@keshav-space Thanks!