Add a memory limit constraint on deployments

This is based on the worker's memory_threshold setting

Fixes ManageIQ#20163

app/models/miq_worker/container_common.rb

@@ -14,6 +14,7 @@ def configure_worker_deployment(definition, replicas = 0)
       container[:image] = "#{container_image_namespace}/#{container_image_name}:#{container_image_tag}"
       container[:env] << {:name => "WORKER_CLASS_NAME", :value => self.class.name}
       container[:env] << {:name => "BUNDLER_GROUPS", :value => self.class.bundler_groups.join(",")}
+      container[:resources] = resource_constraints
     end
 
     def scale_deployment
@@ -25,6 +26,15 @@ def zone_selector
       {"#{Vmdb::Appliance.PRODUCT_NAME.downcase}/zone-#{MiqServer.my_zone}" => "true"}
     end
 
+    def resource_constraints
+      mem_threshold = worker_settings[:memory_threshold]
+      {
+        :limits => {
+          :memory => "#{mem_threshold / 1.megabyte}Mi",
+        }
+      }
+    end
+
     def container_image_namespace
       ENV["CONTAINER_IMAGE_NAMESPACE"]
     end