Fixes #36928 - (sorta) handle load balanced smart proxies when registering hosts

app/controllers/katello/api/rhsm/candlepin_proxies_controller.rb

@@ -474,7 +474,20 @@ def client_authorized?
     def update_host_registered_through(host, headers)
       parent_host = get_parent_host(headers)
       host.subscription_facet.update_attribute(:registered_through, parent_host)
-      content_source_id = get_content_source_id(parent_host)
+      set_host_content_source(host, parent_host)
+    end
+
+    def registering_thru_load_balancer?(hostname)
+      ::SmartProxy.behind_load_balancer(hostname).present?
+    end
+
+    def set_host_content_source(host, content_source_hostname)
+      content_source_id = get_content_source_id(content_source_hostname)
+      if registering_thru_load_balancer?(content_source_hostname)
+        Rails.logger.info "Host %s registered through load balancer %s" % [host.name, content_source_hostname]
+        content_source_id = ::SmartProxy.behind_load_balancer(content_source_hostname)&.first&.id
+      end
+      Rails.logger.warn "Host %s registered through unknown proxy %s" % [host.name, content_source_hostname] if content_source_id.nil?
       host.content_facet.update_attribute(:content_source_id, content_source_id)
     end
 

app/models/katello/concerns/host_managed_extensions.rb

@@ -91,12 +91,17 @@ def update_os_from_facts
 
         def remote_execution_proxies(provider, *_rest)
           proxies = super
-          if (name = subscription_facet&.registered_through)
-            registered_through = SmartProxy.with_features(provider)
+          name = subscription_facet&.registered_through
+          result = []
+          if name.present?
+            result = SmartProxy.with_features(provider)
                                            .authorized
                                            .where(name: name)
+            if result.blank?
+              result = SmartProxy.authorized.behind_load_balancer(name)
+            end
           end
-          proxies[:registered_through] = registered_through || []
+          proxies[:registered_through] = result
           proxies
         end
       end
@@ -193,7 +198,7 @@ def self.find_with_expiring_pools(_key, _operator, days_from_now)
           property :content_views, 'ContentView', desc: 'Returns content views associated with the host'
           property :installed_packages, array_of: 'InstalledPackage', desc: 'Returns a list of packages installed on the host'
         end
-      end
+      end # of included block
 
       def check_host_registration
         if subscription_facet

app/models/katello/concerns/smart_proxy_extensions.rb

@@ -68,6 +68,18 @@ def refresh
         }
         scope :with_content, -> { with_features(PULP_FEATURE, PULP_NODE_FEATURE, PULP3_FEATURE) }
 
+        def self.load_balanced
+          proxies = self.with_content # load balancing is only supported for pulp proxies
+          ids = proxies.select { |proxy| proxy.load_balanced? }.map(&:id)
+          proxies.where(id: ids)
+        end
+
+        def self.behind_load_balancer(load_balancer_hostname)
+          proxies = self.with_content
+          ids = proxies.select { |proxy| proxy.load_balanced? && proxy.registration_host == load_balancer_hostname }.map(&:id)
+          proxies.where(id: ids)
+        end
+
         def self.with_repo(repo)
           joins(:capsule_lifecycle_environments).
             where("#{Katello::CapsuleLifecycleEnvironment.table_name}.lifecycle_environment_id" => repo.environment_id)
@@ -121,6 +133,15 @@ def alternate_content_sources
         SmartProxy.joins(:smart_proxy_alternate_content_sources).where('katello_smart_proxy_alternate_content_sources.smart_proxy_id' => self.id)
       end
 
+      def registration_host
+        url = self.setting('Registration', 'registration_url').presence || self.url
+        URI.parse(url).host
+      end
+
+      def load_balanced?
+        URI.parse(self.url).host != self.registration_host
+      end
+
       def update_content_counts!
         # {:content_view_versions=>{87=>{:repositories=>{1=>{:metadata=>{},:counts=>{:rpms=>98, :module_streams=>9898}}}}}
         new_content_counts = { content_view_versions: {} }

lib/katello.rb

@@ -6,6 +6,7 @@
 require "oauth"
 require "gettext_i18n_rails"
 require "foreman-tasks"
+require "foreman_remote_execution"
 require "rest_client"
 require "anemone"
 require "securerandom"

test/models/concerns/host_managed_extensions_test.rb

@@ -122,6 +122,23 @@ def test_check_cve_attributes
       refute host_attrs.key?(:content_view_id)
       refute host_attrs.key?(:lifecycle_environment_id)
     end
+
+    def test_remote_execution_proxies_registered_through
+      host = FactoryBot.create(:host, :with_content, :with_subscription, :content_view => @library_view, :lifecycle_environment => @library)
+      host.subscription_facet.expects(:registered_through).returns('test-proxy.example.com')
+      rex_feature = Feature.where(:name => "Remote Execution").first_or_create
+      test_proxy = FactoryBot.create(:smart_proxy, :features => [rex_feature], :url => 'http://test-proxy.example.com:9090', :name => 'test-proxy.example.com')
+      assert_equal host.remote_execution_proxies(rex_feature.name)[:registered_through], [test_proxy]
+    end
+
+    def test_remote_execution_proxies_registered_through_load_balancer
+      host = FactoryBot.create(:host, :with_content, :with_subscription, :content_view => @library_view, :lifecycle_environment => @library)
+      host.subscription_facet.expects(:registered_through).returns('unknown-proxy.example.com')
+      rex_feature = Feature.where(:name => "Remote Execution").first_or_create
+      proxy_behind_lb = FactoryBot.create(:smart_proxy, :features => [rex_feature], :url => 'http://test-proxy.example.com:9090', :name => 'test-proxy.example.com')
+      ::SmartProxy.expects(:behind_load_balancer).with('unknown-proxy.example.com').returns([proxy_behind_lb])
+      assert_equal host.remote_execution_proxies(rex_feature.name)[:registered_through], [proxy_behind_lb]
+    end
   end
 
   class HostManagedExtensionsUpdateTest < HostManagedExtensionsTestBase