Dashboard warning when host_names is localhost

app/models/admin_dashboard_data.rb

@@ -10,7 +10,7 @@ class AdminDashboardData
     @json ||= {
       reports: REPORTS.map { |type| Report.find(type) },
       total_users: User.count,
-      problems: [rails_env_check].compact
+      problems: [rails_env_check, host_names_check].compact
     }.merge(
       SiteSetting.version_checks? ? {version_check: DiscourseUpdates.check_version} : {}
     )
@@ -19,4 +19,8 @@ class AdminDashboardData
   def rails_env_check
     I18n.t("dashboard.rails_env_warning", env: Rails.env) unless Rails.env == 'production'
   end
+
+  def host_names_check
+    I18n.t("dashboard.host_names_warning") if ['localhost', 'production.localhost'].include?(Discourse.current_hostname)
+  end
 end

config/locales/server.en.yml

@@ -285,6 +285,7 @@ en:
 
   dashboard:
     rails_env_warning: "Your server is running in %{env} mode."
+    host_names_warning: "Your config/database.yml file is using the default localhost hostname. Update it to use your site's hostname."
 
   site_settings:
     default_locale: "The default language of this Discourse instance (ISO 639-1 Code)"

spec/models/admin_dashboard_data_spec.rb

@@ -21,4 +21,23 @@ describe AdminDashboardData do
     end
   end
 
+  describe 'host_names_check' do
+    subject { AdminDashboardData.new.host_names_check }
+
+    it 'returns nil when host_names is set' do
+      Discourse.stubs(:current_hostname).returns('something.com')
+      subject.should be_nil
+    end
+
+    it 'returns a string when host_name is localhost' do
+      Discourse.stubs(:current_hostname).returns('localhost')
+      subject.should_not be_nil
+    end
+
+    it 'returns a string when host_name is production.localhost' do
+      Discourse.stubs(:current_hostname).returns('production.localhost')
+      subject.should_not be_nil
+    end
+  end
+
 end