Pulp

What should I do about node calls that rely on code that's not specific to nodes? For example, when I call node sync on the parent, it looks like the server just creates a consumer update_content task[0]. I may be mistaken but it looks like this task isn't specific to nodes (at least for the parent—on the child, there is some node specific importer code).

I could either:

1. Add code to pulp core and check if the consumer is a node and then display a warning message
2. Not worry about showing a deprecation warning when code not specific to nodes (but used by nodes) is called.

I'm kind of leaning toward option 2 as I had hoped to keep this change limited to nodes directory.

[0] https://git.io/v1IHM

As mentioned in the bug description, it does indeed look like DeprecationWarning is silenced by default in 2.7. One option would be to run python with '-W all' or something similar in dev mode. I'm not sure exactly where/how to configure this flag though?

Also, we could update the logging code[0] by adding something like:

warnings.simplefilter('always', DeprecationWarning)

I'm not sure how to tell though when we're in a dev setup. Maybe we could add a deprecation config variable?

[0] https://github.com/pulp/pulp/blob/91a1e28c9e7d3dee418d5c7680dbf25c3e7adc63/server/pulp/server/logs.py

I think we should not add the -W and instead use the warnings.simplefilter as you suggest. Adding that to the logging setup code would set that for all server side processes, but you'll also have to add it for pulp-admin and pulp-consumer. Those standalone, client-side binaries don't use the logging code.

In terms of the shared codepaths, I also prefer option 2 where we only add deprecation warnings to code that we know is node specific. Overall I believe for each server side processes (daemon processes) having at least 1 deprecation warning logged for each node operation (sync, publish) would be good. Also for interactive processes (pulp-admin, pulp-consumer) having at least 1 deprecation warning shown in the foreground for each node operation would be good.

bmbouter, you mentioned that we previously deprecated nodes in a release of pulp but looking through the docs/user-guide/release-notes directory of pulp, I am not seeing it. Do you remember the release?

So turning on logging for deprecation warnings is spitting out tons of deprecation warnings in places we don't control like:

Dec 02 09:06:35 dev.example.com pulp[18247]: py.warnings:WARNING: (18247-87552) /usr/lib/python2.7/site-packages/mongoengine/queryset/base.py:461: DeprecationWarning: update is deprecated. Use replace_one, update_one or update_many instead.
Dec 02 09:06:35 dev.example.com pulp[18247]: py.warnings:WARNING: (18247-87552)   upsert=upsert, **write_concern)

This is from mongoengine calling update which pymongo deprecated: https://github.com/mongodb/mongo-python-driver/blob/master/pymongo/collection.py#L2482-L2483

I'm not sure if we want or care about these messages? Another alternative is to define a new deprecation warning like NodeDeprecationWarning and just turn on those.

Let's not enable all deprecation warnings. I really like the idea of declaring a NodeDeprecationWarning and just enabling that one.

Does it make any sense to write a blog post about nodes being deprecated with 2.12 and giving specific recommendations for how users can switch from nodes to a natural sync? I think that would be good. We could link to that blog post from the deprecation statement in the release notes and on nodes.rst pages. That should either become a checklist item or its own task. I think doing it all as 1 task would be good. Whatever you decide, would you be willing to track that work (as checklist item or its own task)?

FYI, here is a draft post on writing blog posts that @dkliban is working on: https://github.com/pulp/pulpproject.org/pull/29

Thank you for doing all of this, it's a big job!

Adding in deprecation warnings to the parent/child code is kind of tricky because there are often multiple places where I can add them. For example, when I bind a repo to a node, we could add a deprecation warning here:

https://git.io/v10R2

But it looks like this also gets called:

https://git.io/v10RM

Also it looks like there are places in the code that I am not sure how to reach. Here's an example:

https://git.io/v10R9

I think the fact that [0] is called by [1] is fine because [1] is the publish repo inside of the pulp_node package so I expect [1] is only called for node calls.

Regarding [2], I believe the platform will call that when a orphan delete occurs. The platform would be running an orphan delete celery task through the node workflow. @jortel could confirm this I think.

[0]: https://git.io/v10R2
[1]: https://git.io/v10RM
[2]: https://git.io/v10R9