Does not redirect user to the custom home page URL on a Geo secondary

If a user is not signed-in and tries to access root_path on a Geo
secondary node, redirects them to the sign-in page. Don't redirect
to the custom home page URL if one is present. Otherwise, it
will break the Geo OAuth workflow always redirecting the user to
the Geo primary node, which prevents access to the secondary node.

ee/app/controllers/ee/root_controller.rb

@@ -15,5 +15,17 @@ module EE
 
       super
     end
+
+    override :redirect_to_home_page_url?
+    def redirect_to_home_page_url?
+      # If a user is not signed-in and tries to access root_path on a Geo
+      # secondary node, redirects them to the sign-in page. Don't redirect
+      # to the custom home page URL if one is present. Otherwise, it
+      # will break the Geo OAuth workflow always redirecting the user to
+      # the Geo primary node, which prevents access to the secondary node.
+      return false if ::Gitlab::Geo.secondary?
+
+      super
+    end
   end
 end

ee/changelogs/unreleased/11594-geo-redirect-after-authentication-prevents-access-to-secondary.yml

+---
+title: Geo - Does not redirect user to the custom home page URL on a Geo secondary
+merge_request: 13447
+author:
+type: fixed

ee/spec/controllers/ee/root_controller_spec.rb

@@ -3,35 +3,98 @@
 require 'spec_helper'
 
 describe RootController do
-  describe 'GET index' do
-    let(:user) { create(:user) }
+  include ::EE::GeoHelpers
 
-    before do
-      stub_licensed_features(operations_dashboard: true)
-      sign_in(user)
-      allow(subject).to receive(:current_user).and_return(user)
-    end
+  describe 'GET #index' do
+    context 'when user is not logged in' do
+      context 'on a Geo primary node' do
+        set(:primary_node) { create(:geo_node, :primary) }
 
-    context 'who has customized their dashboard setting for operations' do
-      before do
-        user.dashboard = 'operations'
-      end
+        before do
+          stub_current_geo_node(primary_node)
+        end
+
+        it 'redirects to the sign-in page' do
+          get :index
+
+          expect(response).to redirect_to(new_user_session_path)
+        end
 
-      it 'redirects to operations dashboard' do
-        get :index
+        context 'when a custom home page URL is defined' do
+          before do
+            stub_application_setting(home_page_url: 'https://custom.gitlab.com/foo')
+          end
 
-        expect(response).to redirect_to operations_path
+          it 'redirects the user to the custom home page URL' do
+            get :index
+
+            expect(response).to redirect_to('https://custom.gitlab.com/foo')
+          end
+        end
       end
 
-      context 'when unlicensed' do
+      context 'on a Geo secondary node' do
+        set(:secondary_node) { create(:geo_node) }
+
         before do
-          stub_licensed_features(operations_dashboard: false)
+          stub_current_geo_node(secondary_node)
         end
 
-        it 'renders the default dashboard' do
+        it 'redirects to the sign-in page' do
           get :index
 
-          expect(response).to render_template 'dashboard/projects/index'
+          expect(response).to redirect_to(new_user_session_path)
+        end
+
+        context 'when a custom home page URL is defined' do
+          before do
+            stub_application_setting(home_page_url: 'https://custom.gitlab.com/foo')
+          end
+
+          it 'redirects to the sign-in page' do
+            get :index
+
+            expect(response).to redirect_to(new_user_session_path)
+          end
+        end
+      end
+    end
+
+    context 'with a user' do
+      let(:user) { create(:user) }
+
+      before do
+        sign_in(user)
+        allow(subject).to receive(:current_user).and_return(user)
+      end
+
+      context 'who has customized their dashboard setting for operations' do
+        before do
+          user.dashboard = 'operations'
+        end
+
+        context 'when licensed' do
+          before do
+            stub_licensed_features(operations_dashboard: true)
+          end
+
+          it 'redirects to operations dashboard' do
+            get :index
+
+            expect(response).to redirect_to operations_path
+          end
+        end
+
+        context 'when unlicensed' do
+          before do
+            stub_licensed_features(operations_dashboard: false)
+          end
+
+          it 'renders the default dashboard' do
+            get :index
+
+            expect(response).to render_template 'dashboard/projects/index'
+          end
         end
       end
     end