Models Count for Containers, run as ```bundle exec rails r count_records.rb```

count_records.rb

classes = [
  Authentication,
  ComputerSystem,
  Container,
  ContainerBuild,
  ContainerBuildPod,
  ContainerComponentStatus,
  ContainerCondition,
  ContainerEnvVar,
  ContainerGroup,
  ContainerImage,
  ContainerImageRegistry,
  ContainerLabelTagMapping,
  ContainerLimit,
  ContainerLimitItem,
  ContainerNode,
  ContainerPortConfig,
  ContainerProject,
  ContainerQuota,
  ContainerQuotaItem,
  ContainerReplicator,
  ContainerRoute,
  ContainerService,
  ContainerServicePortConfig,
  ContainerTemplate,
  ContainerTemplateParameter,
  ContainerVolume,
  CustomAttribute,
  Endpoint,
  ExtManagementSystem,
  Hardware,
  ManageIQ::Providers::Kubernetes::ContainerManager::ContainerGroup,
  ManageIQ::Providers::Kubernetes::ContainerManager::ContainerNode,
  MiqEventDefinition,
  MiqGroup,
  MiqServer,
  OperatingSystem,
  PersistentVolume,
  PersistentVolumeClaim,
  SecurityContext,
  ServerRole,
  Tag,
  Tagging,
  Tenant,
  User,
  Vm
]

sorted = {}
sorted_with_soft_deleted = {}
classes.each do |model|
  relation = model
  relation = relation.where.not(:ems_id => nil) if model.column_names.include?("ems_id")
  relation = relation.where(:deleted_on => nil) if model.column_names.include?("deleted_on")

  sorted[model] = relation.count
  sorted_with_soft_deleted[model] = model.count
end

puts "------------- sorted by counts ------------"
sorted.sort_by { |_key, value| value }.reverse.to_h.each do |k, v|
  puts "#{k.name}:  #{v}"
end

puts "------------- sorted with soft deleted by counts ------------"
sorted_with_soft_deleted.sort_by { |_key, value| value }.reverse.to_h.each do |k, v|
  puts "#{k.name}:  #{v}"
end

total = sorted.values.sum
total_with_soft_deleted = sorted_with_soft_deleted.values.sum

puts "\n"
puts "-------------------------------------------"
puts "Total: #{total} records"
puts "Total with soft deleted: #{total_with_soft_deleted} records"
puts "\n"

ExtManagementSystem.all.each do |ems|
  next unless ems.respond_to?(:container_images)

  puts "\n"
  puts "---------------------------------------------------------------------------------"
  puts "EMS [#{ems.name}] specific relations counts"
  puts "---------------------------------------------------------------------------------"
  puts "\n"

  puts "--------------------------Handpicked relations--------------------------------"
  handpicked_relations = {}
  handpicked_relations_custom_attributes = {}
  [:container_images, :container_projects, :container_nodes, :container_groups, :container_replicators, :container_services,
   :container_routes, :container_templates, :container_builds, :container_build_pods].each do |rel_name|

    next unless ems.respond_to?(rel_name)
    relation = ems.send(rel_name)
    relation_custom_attributes = CustomAttribute.where(
      :resource_type => relation.model.base_class.name,
      :resource_id   => relation,
    )

    handpicked_relations[rel_name] = relation.count
    handpicked_relations_custom_attributes[rel_name] = relation_custom_attributes.count
  end

  handpicked_relations.sort_by { |_key, value| value }.reverse.to_h.each do |k, v|
    puts "#{k}:  #{v}"
    puts "#{k} custom_attributes:  #{handpicked_relations_custom_attributes[k]}"
  end

  puts "--------------------------All relations--------------------------------------------"


  ems.class.reflections.select { |name, reflection| reflection.macro == :has_many }.collect { |name, reflection| [name, ems.send(name).count] }.sort_by(&:second).reverse.each { |n, c| puts "#{n}: #{c}" }
end

nice synthesis 👍
as you mention on gitter, this is missing ContainerEnvVar of active containers — small omission but it's 2nd–3rd biggest table so interesting.

a dirty trick we can do in a standalone script (but not rails c), is just add any missing through relations from
https://github.com/ManageIQ/manageiq/blob/master/app/models/manageiq/providers/container_manager.rb