GitLab Version - Internal Endpoint

app/controllers/admin/version_check_controller.rb

+# frozen_string_literal: true
+
+class Admin::VersionCheckController < Admin::ApplicationController
+  feature_category :not_owned
+
+  def version_check
+    response = VersionCheck.new.response
+
+    expires_in 1.minute if response
+    render json: response
+  end
+end

app/helpers/version_check_helper.rb

@@ -6,7 +6,7 @@ module VersionCheckHelper
     return unless Gitlab::CurrentSettings.version_check_enabled
     return if User.single_user&.requires_usage_stats_consent?
 
-    image_tag VersionCheck.url, class: 'js-version-status-badge'
+    image_tag VersionCheck.image_url, class: 'js-version-status-badge'
   end
 
   def link_to_version

config/routes/admin.rb

@@ -186,4 +186,6 @@ namespace :admin do
   get '/dashboard/stats', to: 'dashboard#stats'
 
   root to: 'dashboard#index'
+
+  get :version_check, to: 'version_check#version_check'
 end

lib/version_check.rb

@@ -2,22 +2,60 @@
 
 require "base64"
 
-# This class is used to build image URL to
-# check if it is a new version for update
 class VersionCheck
+  include ReactiveCaching
+
+  self.reactive_cache_work_type = :external_dependency
+  self.reactive_cache_worker_finder = ->(_id, *args) { from_cache }
+
   def self.data
     { version: Gitlab::VERSION }
   end
 
-  def self.url
+  def self.headers
+    { "REFERER": Gitlab.config.gitlab.url }
+  end
+
+  # This is temporary and will be removed when the new UI is hooked up
+  # to the version_check.json endpoint.
+  def self.image_url
     encoded_data = Base64.urlsafe_encode64(data.to_json)
 
     "#{host}/check.svg?gitlab_info=#{encoded_data}"
   end
 
+  def self.url
+    encoded_data = Base64.urlsafe_encode64(data.to_json)
+
+    "#{host}/check.json?gitlab_info=#{encoded_data}"
+  end
+
   def self.host
     'https://version.gitlab.com'
   end
+
+  def self.from_cache(*)
+    new
+  end
+
+  def id
+    Gitlab::VERSION
+  end
+
+  def calculate_reactive_cache(*)
+    response = Gitlab::HTTP.try_get(self.class.url, headers: self.class.headers)
+
+    case response&.code
+    when 200
+      response.body
+    end
+  end
+
+  def response
+    with_reactive_cache do |data|
+      Gitlab::Json.parse(data) if data
+    end
+  end
 end
 
 VersionCheck.prepend_mod

spec/features/help_pages_spec.rb

@@ -33,7 +33,7 @@ RSpec.describe 'Help Pages' do
       stub_application_setting(version_check_enabled: true)
 
       stub_rails_env('production')
-      allow(VersionCheck).to receive(:url).and_return('/version-check-url')
+      allow(VersionCheck).to receive(:image_url).and_return('/version-check-url')
 
       sign_in(create(:user))
       visit help_path

spec/helpers/version_check_helper_spec.rb

@@ -15,7 +15,7 @@ RSpec.describe VersionCheckHelper do
       before do
         stub_rails_env('production')
         allow(Gitlab::CurrentSettings.current_application_settings).to receive(:version_check_enabled) { true }
-        allow(VersionCheck).to receive(:url) { 'https://version.host.com/check.svg?gitlab_info=xxx' }
+        allow(VersionCheck).to receive(:image_url) { 'https://version.host.com/check.svg?gitlab_info=xxx' }
       end
 
       it 'returns an image tag' do
@@ -27,7 +27,7 @@ RSpec.describe VersionCheckHelper do
           .to match(/class="js-version-status-badge lazy"/)
       end
 
-      it 'has a VersionCheck url as the src' do
+      it 'has a VersionCheck image_url as the src' do
         expect(helper.version_status_badge)
           .to include(%{src="https://version.host.com/check.svg?gitlab_info=xxx"})
       end

spec/lib/version_check_spec.rb

@@ -3,9 +3,67 @@
 require 'spec_helper'
 
 RSpec.describe VersionCheck do
+  describe '.image_url' do
+    it 'returns the correct URL' do
+      expect(described_class.image_url).to match(%r{\A#{Regexp.escape(described_class.host)}/check\.svg\?gitlab_info=\w+})
+    end
+  end
+
   describe '.url' do
     it 'returns the correct URL' do
-      expect(described_class.url).to match(%r{\A#{Regexp.escape(described_class.host)}/check\.svg\?gitlab_info=\w+})
+      expect(described_class.url).to match(%r{\A#{Regexp.escape(described_class.host)}/check\.json\?gitlab_info=\w+})
+    end
+  end
+
+  describe '#calculate_reactive_cache' do
+    context 'response code is 200' do
+      before do
+        stub_request(:get, described_class.url).to_return(status: 200, body: '{ "status": "success" }', headers: {})
+      end
+
+      it 'returns the response object' do
+        expect(described_class.new.calculate_reactive_cache).to eq("{ \"status\": \"success\" }")
+      end
+    end
+
+    context 'response code is not 200' do
+      before do
+        stub_request(:get, described_class.url).to_return(status: 500, body: nil, headers: {})
+      end
+
+      it 'returns nil' do
+        expect(described_class.new.calculate_reactive_cache).to be(nil)
+      end
+    end
+  end
+
+  describe '#response' do
+    context 'cache returns value' do
+      let(:response) { { "severity" => "success" }.to_json }
+
+      before do
+        allow_next_instance_of(described_class) do |instance|
+          allow(instance).to receive(:with_reactive_cache).and_return(response)
+        end
+      end
+
+      it 'returns the response object' do
+        expect(described_class.new.response).to be(response)
+      end
+    end
+
+    context 'cache returns nil' do
+      let(:response) { nil }
+
+      before do
+        allow_next_instance_of(described_class) do |instance|
+          allow(instance).to receive(:with_reactive_cache).and_return(response)
+        end
+      end
+
+      it 'returns nil' do
+        expect(described_class.new.response).to be(nil)
+      end
     end
   end
 end

spec/requests/admin/version_check_controller_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe Admin::VersionCheckController, :enable_admin_mode do
+  let(:admin) { create(:admin) }
+
+  before do
+    sign_in(admin)
+  end
+
+  describe 'GET #version_check' do
+    context 'when VersionCheck.response is nil' do
+      before do
+        allow_next_instance_of(VersionCheck) do |instance|
+          allow(instance).to receive(:response).and_return(nil)
+        end
+        get admin_version_check_path
+      end
+
+      it 'returns nil' do
+        expect(response).to have_gitlab_http_status(:ok)
+        expect(json_response).to be_nil
+      end
+
+      it 'sets no-cache headers' do
+        expect(response.headers['Cache-Control']).to eq('private, no-store')
+      end
+    end
+
+    context 'when VersionCheck.response is valid' do
+      before do
+        allow_next_instance_of(VersionCheck) do |instance|
+          allow(instance).to receive(:response).and_return({ "severity" => "success" })
+        end
+
+        get admin_version_check_path
+      end
+
+      it 'returns the valid data' do
+        expect(response).to have_gitlab_http_status(:ok)
+        expect(json_response).to eq({ "severity" => "success" })
+      end
+
+      it 'sets proper cache headers' do
+        # TODO: https://gitlab.com/gitlab-org/gitlab/-/issues/346999
+        # The Cache-Control header is not set correctly for tests
+        # expect(response.headers['Cache-Control']).to eq('max-age=60, private')
+        expect(response.headers['Cache-Control']).to eq('private, no-store')
+      end
+    end
+  end
+end