Use a controller to hold request values

lib/gitlab/middleware/read_only.rb

@@ -5,15 +5,13 @@ module Gitlab
       APPLICATION_JSON = 'application/json'.freeze
       API_VERSIONS = (3..4)
 
-      def initialize(app)
+      class Controller
+        def initialize(app, env)
           @app = app
-        @whitelisted = internal_routes
-      end
-
-      def call(env)
           @env = env
-        @route_hash = nil
+        end
 
+        def call
           if disallowed_request? && Gitlab::Database.read_only?
             Rails.logger.debug('GitLab ReadOnly: preventing possible non read-only operation')
             error_message = 'You cannot do writing operations on a read-only GitLab instance'
@@ -28,17 +26,14 @@ module Gitlab
             end
           end
 
-        @app.call(env).tap { @env = nil }
+          @app.call(@env)
         end
 
         private
 
-      def internal_routes
-        API_VERSIONS.flat_map { |version| "api/v#{version}/internal" }
-      end
-
         def disallowed_request?
-        DISALLOWED_METHODS.include?(@env['REQUEST_METHOD']) && !whitelisted_routes
+          DISALLOWED_METHODS.include?(@env['REQUEST_METHOD']) &&
+            !whitelisted_routes
         end
 
         def json_request?
@@ -66,7 +61,7 @@ module Gitlab
         end
 
         def whitelisted_routes
-        grack_route || @whitelisted.any? { |path| request.path.include?(path) } || lfs_route || sidekiq_route
+          grack_route || ReadOnly.internal_routes.any? { |path| request.path.include?(path) } || lfs_route || sidekiq_route
         end
 
         def sidekiq_route
@@ -87,5 +82,19 @@ module Gitlab
           route_hash[:controller] == 'projects/lfs_api' && route_hash[:action] == 'batch'
         end
       end
+
+      def self.internal_routes
+        @internal_routes ||=
+          API_VERSIONS.map { |version| "api/v#{version}/internal" }
+      end
+
+      def initialize(app)
+        @app = app
+      end
+
+      def call(env)
+        Controller.new(@app, env).call
+      end
+    end
   end
 end

spec/lib/gitlab/middleware/read_only_spec.rb

@@ -11,8 +11,10 @@ describe Gitlab::Middleware::ReadOnly do
 
   RSpec::Matchers.define :disallow_request do
     match do |middleware|
-      flash = middleware.send(:rack_flash)
-      flash['alert'] && flash['alert'].include?('You cannot do writing operations')
+      alert = middleware.env['rack.session'].to_hash
+        .dig('flash', 'flashes', 'alert')
+
+      alert&.include?('You cannot do writing operations')
     end
   end
 
@@ -34,7 +36,22 @@ describe Gitlab::Middleware::ReadOnly do
     rack.to_app
   end
 
-  subject { described_class.new(fake_app) }
+  let(:observe_env) do
+    Module.new do
+      attr_reader :env
+
+      def call(env)
+        @env = env
+        super
+      end
+    end
+  end
+
+  subject do
+    app = described_class.new(fake_app)
+    app.extend(observe_env)
+    app
+  end
 
   let(:request) { Rack::MockRequest.new(rack_stack) }