GIT-XX: making health check conditiopns configurable (#4823)

app/controllers/health_check_controller.rb

@@ -26,9 +26,9 @@ class HealthCheckController < ApplicationController
     @cache_expire = 10.seconds
 
     begin
-      cache_check
-      database_check
-      email_check
+      cache_check if Rails.configuration.health_check_cache_enabled
+      database_check if Rails.configuration.health_check_db_enabled
+      email_check if Rails.configuration.health_check_email_enabled
     rescue => e
       response = "Health Check Failure: #{e}"
     end

config/application.rb

@@ -188,5 +188,9 @@ module Greenlight
     config.max_avatar_size = ENV['MAX_AVATAR_SIZE'].to_i.zero? ? 100_000 : ENV['MAX_AVATAR_SIZE'].to_i
 
     config.social_switching = ENV['SOCIAL_SWITCHING'] == "true"
+
+    config.health_check_cache_enabled = ENV.fetch('ENABLE_HEALTH_CHECK_CACHE', 'true').casecmp?('true')
+    config.health_check_db_enabled = ENV.fetch('ENABLE_HEALTH_CHECK_DB', 'true').casecmp?('true')
+    config.health_check_email_enabled = ENV.fetch('ENABLE_HEALTH_CHECK_EMAIL', 'true').casecmp?('true')
   end
 end

sample.env

@@ -371,3 +371,13 @@ MAX_AVATAR_SIZE=100000
 # Due CCVE-2015-9284, this setting needs to be enabled for omniauth to respond GET requests.
 #   ENABLE_OMNIAUTH_GET=true|<false>
 ENABLE_OMNIAUTH_GET=false
+
+# By default health_check proves the availability of CACHE, DB and EMAIL server
+# but when the time of response requires is highly sensitive, in some cases it is necessary to disable
+# them and relay only on the http response. In such case these env variables can be set.
+#    ENABLE_HEALTH_CHECK_CACHE=<true>|false
+#    ENABLE_HEALTH_CHECK_DB=<true>|false
+#    ENABLE_HEALTH_CHECK_EMAIL=<true>|false
+ENABLE_HEALTH_CHECK_CACHE=true
+ENABLE_HEALTH_CHECK_DB=true
+ENABLE_HEALTH_CHECK_EMAIL=true