Make redis and redis cache work with connection pool

[jnunemaker]

This makes it so redis and redis cache work with a redis instance or a connection pool instance that generates redis instances.

@cymen @j-castellanos @maleksiuk @BilalBudhani @tanelsuurhans @gstokkink Any thoughts on this? Seems like it'll just work.

refs #826, #839, #835

To Use

All you need to do is configure your adapter:

Flipper.configure do |config|
  config.adapter do
    pool = ConnectionPool.new(size: 5, timeout: 5) { Redis.new(...) }
    Flipper::Adapters::Redis.new(pool)
  end
end

If you're using redis cache, it's the same thing but pass connetion pool instance for cache instead of redis instance.

[gstokkink]

@jnunemaker nice, thanks! Any chance of a new release soonish?

[jnunemaker]

Yes. Trying to get a couple more fixes in now.

[j-castellanos]

@jnunemaker great news! Keep us posted so we can update and then I can remove this code that I have been using in the meantime:

module Flipper
   module Adapters
     module Poolable
       def initialize(client_or_pool = nil, key_prefix: nil)
         @pool = nil
         @client = nil
         if client_or_pool.is_a?(ConnectionPool)
           @pool = client_or_pool
         else
           @client = client_or_pool
         end
         @key_prefix = key_prefix
       end

       def self.included(klass)
         klass.superclass.instance_methods(false).each do |method|
           klass.define_method method do |*args|
             return super(*args) unless @client.nil?

             @pool.with do |client|
               @client = client
               super(*args)
             ensure
               @client = nil
             end
           end
         end
       end
     end
   end
 end

Just out of curiosity, have people requested pooling for adapter other than Redis? If so you can probably just make clients for all adapters a pool with a default size of 1 to mimic current behavior.

[maleksiuk]

@jnunemaker This looks great! I appreciate the straightforward approach and look forward to using it. Thanks for working on this.

[BilalBudhani]

looks nice and clean. I have created a todo in our internally to use this adapter. I will report back once I have enough data. Thank you @jnunemaker!

[gstokkink]

About to use this in production 😄

[jnunemaker]

🔥 in the 🕳️ !!!