Allow to reset state

[fatkodima]

#249 (comment)

I can think of 2 (not functionally equal) implementations:

1. Rack::Attack.reset! which really resets (deletes) specific keys in cache store and can be used for testing as well as production. But, while this can be implemented for most of cache stores (using https://api.rubyonrails.org/classes/ActiveSupport/Cache/Store.html#method-i-delete_matched), this is not (and can't be) supported by memcache (the second most popular cache store), because to reset state, we should know exact key names, which is impossible for production considering rack-attack's dynamic key names nature. Unfortunately, memcache does not support deleting based on patterns/prefixes, like in redis. And need to figure out how to use this with custom, created by user, cache stores.
   Also, personally, I don't think this is a very popular usecase to reset production rack-attack cache. I have used this once to shrink redis memory usage, implemented as a simple rake task executing scan and del on redis. I think, for general use, changing keys prefix and let the backed store prune old entries here is a valid solution.

2. Implementation only to support user tests. I implemented this version here. Example of usage:

# test_helper.rb
Rack::Attack.test_mode

# some_test_file.rb
...
setup do
  Rack::Attack.cache.store.clear
end
...

After agreeing on implementation, will add missing tests and documentation.

[grzuy]

#249 (comment)

I can think of 2 (not functionally equal) implementations:

1. `Rack::Attack.reset!` which really resets (deletes) specific keys in cache store and can be used for testing as well as production. But, while this can be implemented for most of cache stores (using https://api.rubyonrails.org/classes/ActiveSupport/Cache/Store.html#method-i-delete_matched), this is not (and can't be) supported by memcache (the second most popular cache store), because to reset state, we should know exact key names, which is impossible for production considering rack-attack's dynamic key names nature. Unfortunately, memcache does not support deleting based on patterns/prefixes, like in redis. And need to figure out how to use this with custom, created by user, cache stores.
   Also, personally, I don't think this is a very popular usecase to reset _production_ rack-attack cache. I have used this once to shrink redis memory usage, implemented as a simple rake task executing `scan` and `del` on redis. I think, for general use, changing keys prefix and let the backed store prune old entries here is a valid solution.

Good call.

I would still consider providing a Rack::Attack.reset! method that depends on the store #delete_matched method (passing the prefix) which will work for redis and memory_store.

For mem_cache users wanting to reset in their test suites will have the option to:

1. use the memory_store for the test suite and use this new .reset! method
2. clear all mem_cache during tests

2. Implementation only to support user tests. I implemented this version here. Example of usage:

# test_helper.rb
Rack::Attack.test_mode

# some_test_file.rb
...
setup do
  Rack::Attack.cache.store.clear
end
...

After agreeing on implementation, will add missing tests and documentation.

[fatkodima]

@grzuy Updated with your suggestions. I haven't added any readme notes. I think it is better to add all of them as third subtask of #301

[grzuy]

Thanks for the updates!

[grzuy]

MisconfiguredStoreError was conceived to let a user know it need to reconfigure rack-attack or nothing will work.

In this particular case, not sure we're exactly there. This would more like "Everything will work fine with your current store but you won't be able to use the #reset! method"? Maybe IncompatibleStoreError for the constant?

[grzuy]

Sounds like everything in this method implementation is interacting with cache-only stuff (store and prefix).
Should we move reset! inside Cache and make the implementation here just cache.reset!?

[fatkodima]

Updated.

[grzuy]

Awesome, thank you!

[camilova]

Should Rack::Attack::reset! remove current IPs that I have listed with safelist_ip ?
Because I'm trying to remove the IPs, but the new reset! method doesnt remove them and does not raise any error. Is there a way to remove from cache only one specific IP that I was added through safelist_ip?

[jdelStrother]

Any chance of getting a new release with this in?

[grzuy]

Released in v6.3.0.

[grzuy]

Should Rack::Attack::reset! remove current IPs that I have listed with safelist_ip ?
Because I'm trying to remove the IPs, but the new reset! method doesnt remove them and does not raise any error. Is there a way to remove from cache only one specific IP that I was added through safelist_ip?

Hi @camilova , #safelist_ip doesn't write anything to cache.

[camilova]

Thanks! I had a misconception, but now I know that `.clear_configuration` is what I was looking for.