Merge pull request #25 from joinhandshake/support-schema-cache

Add support for setting the schema cache on each replica pool

lib/knockoff.rb

@@ -49,6 +49,10 @@ def config
       @config ||= Config.new
     end
 
+    def set_schema_cache(cache)
+      replica_pool.set_schema_cache(cache)
+    end
+
     def base_transaction_depth
       @base_transaction_depth ||= begin
         testcase = ActiveSupport::TestCase

lib/knockoff/config.rb

@@ -95,18 +95,24 @@ def parse_knockoff_replica_envs_to_configs
             end
 
           # Store the hash in configuration and use it when we establish the connection later.
+          # TODO: In ActiveRecord >= 6, this is a deprecated way to set a configuration. However
+          # there appears to be an issue when calling `ActiveRecord::Base.configurations.to_h` in
+          # version 6.0.4.8 where
+          # multi-database setup is being ignored / dropped. For example if a database.yml setup
+          # has something like..
+          #
+          # development:
+          #   primary:
+          #     ...
+          #   other:
+          #     ...
+          #
+          # then the 'other' database configuration is being dropped.
           key = "knockoff_replica_#{index}"
           config = replica_config.merge(uri_config)
+          ActiveRecord::Base.configurations[key] = config
 
-          if ActiveRecord::VERSION::MAJOR >= 6
-            full_config = ActiveRecord::Base.configurations.to_h.merge(key => config)
-
-            ActiveRecord::Base.configurations = full_config
-            @replicas_configurations[key] = config
-          else
-            ActiveRecord::Base.configurations[key] = config
-            @replicas_configurations[key] = config
-          end
+          @replicas_configurations[key] = config
         rescue URI::InvalidURIError
           Rails.logger.info "LOG NOTIFIER: Invalid URL specified in follower_env_keys. Not including URI, which may result in no followers used." # URI is purposely not printed to logs
           # Return a 'nil' which will be removed from

lib/knockoff/replica_connection_pool.rb

@@ -30,6 +30,12 @@ def reconnect_all_replicas!
       end
     end
 
+    def set_schema_cache(cache)
+      @pool.each do |_name, klass|
+        klass.connection_pool.schema_cache = cache
+      end
+    end
+
     def random_replica_connection
       @pool[@pool.keys.sample]
     end

lib/knockoff/version.rb

@@ -1,3 +1,3 @@
 module Knockoff
-  VERSION = '1.2.0'.freeze
+  VERSION = '1.3.0'.freeze
 end

spec/knockoff_spec.rb

@@ -83,6 +83,14 @@ def on_replica?
       end
     end
 
+    context 'setting schema cache' do
+      it 'sets the cache to each pool schema_cache value' do
+        expect(Knockoff::KnockoffReplica0.connection_pool.schema_cache).to be_nil
+        Knockoff.set_schema_cache('test')
+        expect(Knockoff::KnockoffReplica0.connection_pool.schema_cache).to eq 'test'
+      end
+    end
+
     context 'in transaction' do
       it 'raises error in transaction if replica is attempted' do
         User.transaction do