From 09256509fab4a40bb8c0bb5575bd76ea68b237f2 Mon Sep 17 00:00:00 2001
From: Jason Weathered <jason@jasoncodes.com>
Date: Fri, 26 Oct 2018 15:03:25 +1000
Subject: [PATCH 1/3] Fix memory leak in readiness health check endpoint

---
 app/controllers/health_controller.rb    | 2 +-
 spec/requests/health_controller_spec.rb | 6 ++++++
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/app/controllers/health_controller.rb b/app/controllers/health_controller.rb
index aec10bc97..b068d21a6 100644
--- a/app/controllers/health_controller.rb
+++ b/app/controllers/health_controller.rb
@@ -33,7 +33,7 @@ def run_mongo_check
   end
 
   def impatient_mongoid_client
-    @impatient_mongoid_client ||= Mongo::Client.new(
+    @@impatient_mongoid_client ||= Mongo::Client.new(
       Errbit::Config.mongo_url,
       server_selection_timeout: 0.5,
       connect_timeout:          0.5,
diff --git a/spec/requests/health_controller_spec.rb b/spec/requests/health_controller_spec.rb
index 7a28ad012..b381e0764 100644
--- a/spec/requests/health_controller_spec.rb
+++ b/spec/requests/health_controller_spec.rb
@@ -2,6 +2,12 @@
   let(:errbit_app) { Fabricate(:app, api_key: 'APIKEY') }
 
   describe "readiness" do
+    before do
+      HealthController.class_variables.each do |name|
+        HealthController.remove_class_variable name
+      end
+    end
+
     it 'can let you know when the app is ready to receive requests' do
       get '/health/readiness'
       expect(response).to be_success

From 387146024534611da4310c87d652a040b9145e38 Mon Sep 17 00:00:00 2001
From: Jason Weathered <jason@jasoncodes.com>
Date: Fri, 26 Oct 2018 16:33:10 +1000
Subject: [PATCH 2/3] Ignore warning about using a class variable for global
 memorisation

---
 app/controllers/health_controller.rb | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/app/controllers/health_controller.rb b/app/controllers/health_controller.rb
index b068d21a6..e8ee0c1ee 100644
--- a/app/controllers/health_controller.rb
+++ b/app/controllers/health_controller.rb
@@ -32,6 +32,7 @@ def run_mongo_check
     impatient_mongoid_client.close
   end
 
+  # rubocop:disable Style/ClassVars
   def impatient_mongoid_client
     @@impatient_mongoid_client ||= Mongo::Client.new(
       Errbit::Config.mongo_url,
@@ -40,4 +41,5 @@ def impatient_mongoid_client
       socket_timeout:           0.5
     )
   end
+  # rubocop:enable Style/ClassVars
 end

From 00cbfcf4098188038e390943254855216f0fd1f4 Mon Sep 17 00:00:00 2001
From: Jason Weathered <jason@jasoncodes.com>
Date: Wed, 31 Oct 2018 08:07:46 +1000
Subject: [PATCH 3/3] Promote impatient_mongoid_client to a class method

---
 app/controllers/health_controller.rb    | 22 +++++++++++-----------
 spec/requests/health_controller_spec.rb |  4 ++--
 2 files changed, 13 insertions(+), 13 deletions(-)

diff --git a/app/controllers/health_controller.rb b/app/controllers/health_controller.rb
index e8ee0c1ee..73b894b03 100644
--- a/app/controllers/health_controller.rb
+++ b/app/controllers/health_controller.rb
@@ -19,8 +19,19 @@ def api_key_tester
     render json: { ok: is_good_result }, status: response_status
   end
 
+  def self.impatient_mongoid_client
+    @impatient_mongoid_client ||= Mongo::Client.new(
+      Errbit::Config.mongo_url,
+      server_selection_timeout: 0.5,
+      connect_timeout:          0.5,
+      socket_timeout:           0.5
+    )
+  end
+
 private
 
+  delegate :impatient_mongoid_client, to: :class
+
   def run_mongo_check
     # collections might be empty which is ok but it will raise an exception if
     # database cannot be contacted
@@ -31,15 +42,4 @@ def run_mongo_check
   ensure
     impatient_mongoid_client.close
   end
-
-  # rubocop:disable Style/ClassVars
-  def impatient_mongoid_client
-    @@impatient_mongoid_client ||= Mongo::Client.new(
-      Errbit::Config.mongo_url,
-      server_selection_timeout: 0.5,
-      connect_timeout:          0.5,
-      socket_timeout:           0.5
-    )
-  end
-  # rubocop:enable Style/ClassVars
 end
diff --git a/spec/requests/health_controller_spec.rb b/spec/requests/health_controller_spec.rb
index b381e0764..c122c4225 100644
--- a/spec/requests/health_controller_spec.rb
+++ b/spec/requests/health_controller_spec.rb
@@ -3,8 +3,8 @@
 
   describe "readiness" do
     before do
-      HealthController.class_variables.each do |name|
-        HealthController.remove_class_variable name
+      if HealthController.instance_variable_defined? :@impatient_mongoid_client
+        HealthController.remove_instance_variable :@impatient_mongoid_client
       end
     end