Command to remove unused switches/flags

[cristianowa]

In our usage of django-waffle when switches are removed they often are left in at least one environment database without any meaningful use.

The cost it self is irrelevant for a DB, but checking for active switches (usually debugging a production issue) get more complex overtime.

I have made this script to clean the switches and executed it on Django shell.

from waffle.models import *
switches = Switch.objects.all()

from subprocess import getoutput
from subprocess import getstatusoutput as cmd

print("name", "is_active", "created", "modified")
for switch in switches:
    switch_not_found, _ = cmd("grep -ri {switch.name} *")
    if switch_not_found:
       print(switch.name, switch.is_active, switch.created, switch.modified)
       switch.delete()

I saw there is already a command for deleting data.

My proposal here is to create a command like waffle_remove_unused with options for switches, flags and samples, and also having a dry-run (just printing what would be deleted).

If that is OK I would be glad to work on a PR for it.

The first thing being changing that grep to a Python implementation. Second is to make this generic to Samples and Flags as well.

[clintonb]

A pull request is welcome. I, personally, would be hesitant to use such a command due to lack of trust. It's far simpler for me to grep/search the code myself than hope someone else's command does the right thing. But, that's me.

[cristianowa]

Got it @clintonb, thanks for the feedback. I think the command should not be used in all cases, but in some it makes sense. In our case we have a system with hundreds of feature flags, and a lot of them were forgotten/lost in the process of removal.

I will work on the code and will open the PR as soon as I can.

[cristianowa]

@clintonb When you have the time, please share you thoughts on #493 . 🙂