Add Group Migration realtime_changes endpoint

  - Add realtime_changes endpoint to Import::BulkImportsController,
    similar to Import::BaseController in order to update importer
    status without refreshing the page, similar to what we do in
    other importers.

app/controllers/import/bulk_imports_controller.rb

@@ -8,6 +8,8 @@ class Import::BulkImportsController < ApplicationController
 
   feature_category :importers
 
+  POLLING_INTERVAL = 3_000
+
   rescue_from BulkImports::Clients::Http::ConnectionError, with: :bulk_import_connection_error
 
   def configure
@@ -34,6 +36,12 @@ class Import::BulkImportsController < ApplicationController
     render json: :ok
   end
 
+  def realtime_changes
+    Gitlab::PollingInterval.set_header(response, interval: POLLING_INTERVAL)
+
+    render json: current_user_bulk_imports.to_json(only: [:id], methods: [:status_name])
+  end
+
   private
 
   def serialized_importable_data
@@ -152,4 +160,8 @@ class Import::BulkImportsController < ApplicationController
   def sanitized_filter_param
     @filter ||= sanitize(params[:filter])&.downcase
   end
+
+  def current_user_bulk_imports
+    current_user.bulk_imports.gitlab
+  end
 end

config/routes/import.rb

@@ -63,6 +63,7 @@ namespace :import do
   resource :bulk_imports, only: [:create] do
     post :configure
     get :status
+    get :realtime_changes
   end
 
   resource :manifest, only: [:create, :new], controller: :manifest do

spec/controllers/import/bulk_imports_controller_spec.rb

@@ -149,6 +149,22 @@ RSpec.describe Import::BulkImportsController do
         end
       end
 
+      describe 'GET realtime_changes' do
+        let_it_be(:bulk_import) { create(:bulk_import, :created, user: user) }
+
+        it 'returns bulk imports created by current user' do
+          get :realtime_changes
+
+          expect(json_response).to eq([{ 'id' => bulk_import.id, 'status_name' => bulk_import.status_name.to_s }])
+        end
+
+        it 'sets a Poll-Interval header' do
+          get :realtime_changes
+
+          expect(response.headers['Poll-Interval']).to eq(Import::BulkImportsController::POLLING_INTERVAL.to_s)
+        end
+      end
+
       describe 'POST create' do
         let(:instance_url) { "http://fake-intance" }
         let(:pat) { "fake-pat" }