Only apply CSP in production mode

config/initializers/content_security_policy.rb

@@ -2,9 +2,10 @@
 # For further information see the following documentation
 # https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Security-Policy
 
-assets_host = Rails.configuration.action_controller.asset_host || "https://#{ENV['WEB_DOMAIN'] || ENV['LOCAL_DOMAIN']}"
+if Rails.env.production?
+  assets_host = Rails.configuration.action_controller.asset_host || "https://#{ENV['WEB_DOMAIN'] || ENV['LOCAL_DOMAIN']}"
 
-Rails.application.config.content_security_policy do |p|
+  Rails.application.config.content_security_policy do |p|
     p.base_uri        :none
     p.default_src     :none
     p.frame_ancestors :none
@@ -15,6 +16,7 @@ Rails.application.config.content_security_policy do |p|
     p.media_src       :self, :data, assets_host
     p.frame_src       :self, :https
     p.connect_src     :self, assets_host, Rails.configuration.x.streaming_api_base_url
+  end
 end