add task evm:inventory

this outputs general counts for all inventories

app/models/ext_management_system.rb

@@ -678,6 +678,21 @@ def tenant_identity
     User.super_admin.tap { |u| u.current_group = tenant.default_miq_group }
   end
 
+  def self.output_inventory_status
+    data = includes(:zone)
+           .select(:id, :zone_id, :name, :total_hosts, :total_vms, :total_clusters)
+           .map do |ems|
+             [
+               ems.region_id, ems.zone.name, ems.name,
+               ems.total_clusters, ems.total_hosts, ems.total_vms, ems.total_storages
+             ]
+           end
+    data = data.sort_by { |e| [e[1], e[2], e[3]] }
+
+    header = %w(region zone ems clusters hosts vms storages)
+    puts data.unshift(header).tableize unless data.empty?
+  end
+
   private
 
   def build_connection(options = {})

lib/tasks/evm.rake

@@ -50,6 +50,11 @@ namespace :evm do
     EvmApplication.status(true)
   end
 
+  desc "Describe inventory of the ManageIQ EVM Application"
+  task :inventory => :environment do
+    ExtManagementSystem.output_inventory_status
+  end
+
   desc "Write a remote region id to this server's REGION file"
   task :join_region => :environment do
     configured_region = ApplicationRecord.region_number_from_sequence.to_i