Update find_least_used_host method to evaluate hosts based on utilization. Without this change the determination is based on VM count. Additionally, a method is added to find the least used host compatible with the provided VM in order to support migrating a VM at checkout. Lastly, a capability is added to migrate VMs to a provided host, which also supports migrating VMs at checkout.

Add method to check if vsphere connection is alive. Replace repeated usage of checking the current time in a begin/rescue block with this method.

lib/vmpooler/vsphere_helper.rb

@@ -17,11 +17,7 @@ module Vmpooler
     end
 
     def add_disk(vm, size, datastore)
-      begin
-        @connection.serviceInstance.CurrentTime
-      rescue
-        initialize
-      end
+      vsphere_connection_alive? @connection
 
       return false unless size.to_i > 0
 
@@ -71,22 +67,14 @@ module Vmpooler
     end
 
     def find_datastore(datastorename)
-      begin
-        @connection.serviceInstance.CurrentTime
-      rescue
-        initialize
-      end
+      vsphere_connection_alive? @connection
 
       datacenter = @connection.serviceInstance.find_datacenter
       datacenter.find_datastore(datastorename)
     end
 
     def find_device(vm, deviceName)
-      begin
-        @connection.serviceInstance.CurrentTime
-      rescue
-        initialize
-      end
+      vsphere_connection_alive? @connection
 
       vm.config.hardware.device.each do |device|
         return device if device.deviceInfo.label == deviceName
@@ -96,11 +84,7 @@ module Vmpooler
     end
 
     def find_disk_controller(vm)
-      begin
-        @connection.serviceInstance.CurrentTime
-      rescue
-        initialize
-      end
+      vsphere_connection_alive? @connection
 
       devices = find_disk_devices(vm)
 
@@ -114,11 +98,7 @@ module Vmpooler
     end
 
     def find_disk_devices(vm)
-      begin
-        @connection.serviceInstance.CurrentTime
-      rescue
-        initialize
-      end
+      vsphere_connection_alive? @connection
 
       devices = {}
 
@@ -146,11 +126,7 @@ module Vmpooler
     end
 
     def find_disk_unit_number(vm, controller)
-      begin
-        @connection.serviceInstance.CurrentTime
-      rescue
-        initialize
-      end
+      vsphere_connection_alive? @connection
 
       used_unit_numbers = []
       available_unit_numbers = []
@@ -175,11 +151,7 @@ module Vmpooler
     end
 
     def find_folder(foldername)
-      begin
-        @connection.serviceInstance.CurrentTime
-      rescue
-        initialize
-      end
+      vsphere_connection_alive? @connection
 
       datacenter = @connection.serviceInstance.find_datacenter
       base = datacenter.vmFolder
@@ -196,39 +168,96 @@ module Vmpooler
       base
     end
 
-    def find_least_used_host(cluster)
+    # Returns an array containing cumulative CPU and memory utilization of a host, and its object reference
+    # Params:
+    # +model+:: CPU arch version to match on
+    # +limit+:: Hard limit for CPU or memory utilization beyond which a host is excluded for deployments
+    def get_host_utilization(host, model=nil, limit=90)
+      if model
+        return nil unless host_has_cpu_model? host, model
+      end
+      return nil if host.runtime.inMaintenanceMode
+      return nil unless host.overallStatus == 'green'
+
+      cpu_utilization = cpu_utilization_for host
+      memory_utilization = memory_utilization_for host
+
+      return nil if cpu_utilization > limit
+      return nil if memory_utilization > limit
+
+      [ cpu_utilization + memory_utilization, host ]
+    end
+
+    def host_has_cpu_model?(host, model)
+       get_host_cpu_arch_version(host) == model
+    end
+
+    def get_host_cpu_arch_version(host)
+      cpu_model = host.hardware.cpuPkg[0].description
+      cpu_model_parts = cpu_model.split()
+      arch_version = cpu_model_parts[4]
+      arch_version
+    end
+
+    def cpu_utilization_for(host)
+      cpu_usage = host.summary.quickStats.overallCpuUsage
+      cpu_size = host.summary.hardware.cpuMhz * host.summary.hardware.numCpuCores
+      (cpu_usage.to_f / cpu_size.to_f) * 100
+    end
+
+    def memory_utilization_for(host)
+      memory_usage = host.summary.quickStats.overallMemoryUsage
+      memory_size = host.summary.hardware.memorySize / 1024 / 1024
+      (memory_usage.to_f / memory_size.to_f) * 100
+    end
+
+    def vsphere_connection_alive?(connection)
       begin
-        @connection.serviceInstance.CurrentTime
+        connection.serviceInstance.CurrentTime
       rescue
         initialize
       end
+    end
 
-      hosts = {}
-      hosts_sort = {}
+    def find_least_used_host(cluster)
+      vsphere_connection_alive? @connection
 
+      cluster_object = find_cluster(cluster)
+      target_hosts = get_cluster_host_utilization(cluster_object)
+      least_used_host = target_hosts.sort[0][1]
+      least_used_host
+    end
+
+    def find_cluster(cluster)
       datacenter = @connection.serviceInstance.find_datacenter
-      datacenter.hostFolder.children.each do |folder|
-        next unless folder.name == cluster
-        folder.host.each do |host|
-          if
-            (host.overallStatus == 'green') &&
-            (!host.runtime.inMaintenanceMode)
+      datacenter.hostFolder.children.find { |cluster_object| cluster_object.name == cluster }
+    end
 
-            hosts[host.name] = host
-            hosts_sort[host.name] = host.vm.length
-          end
-        end
+    def get_cluster_host_utilization(cluster)
+      cluster_hosts = []
+      cluster.host.each do |host|
+        host_usage = get_host_utilization(host)
+        cluster_hosts << host_usage if host_usage
       end
+      cluster_hosts
+    end
 
-      hosts[hosts_sort.sort_by { |_k, v| v }[0][0]]
+    def find_least_used_compatible_host(vm)
+      vsphere_connection_alive? @connection
+
+      source_host = vm.summary.runtime.host
+      model = get_host_cpu_arch_version(source_host)
+      cluster = source_host.parent
+      target_hosts = []
+      cluster.host.each do |host|
+        host_usage = get_host_utilization(host, model)
+        target_hosts << host_usage if host_usage
+      end
+      target_hosts.sort[0][1]
     end
 
     def find_pool(poolname)
-      begin
-        @connection.serviceInstance.CurrentTime
-      rescue
-        initialize
-      end
+      vsphere_connection_alive? @connection
 
       datacenter = @connection.serviceInstance.find_datacenter
       base = datacenter.hostFolder
@@ -257,21 +286,13 @@ module Vmpooler
     end
 
     def find_vm(vmname)
-      begin
-        @connection.serviceInstance.CurrentTime
-      rescue
-        initialize
-      end
+      vsphere_connection_alive? @connection
 
       @connection.searchIndex.FindByDnsName(vmSearch: true, dnsName: vmname)
     end
 
     def find_vm_heavy(vmname)
-      begin
-        @connection.serviceInstance.CurrentTime
-      rescue
-        initialize
-      end
+      vsphere_connection_alive? @connection
 
       vmname = vmname.is_a?(Array) ? vmname : [vmname]
       containerView = get_base_vm_container_from @connection
@@ -321,11 +342,7 @@ module Vmpooler
     end
 
     def find_vmdks(vmname, datastore)
-      begin
-        connection.serviceInstance.CurrentTime
-      rescue
-        initialize
-      end
+      vsphere_connection_alive? @connection
 
       disks = []
 
@@ -344,11 +361,7 @@ module Vmpooler
     end
 
     def get_base_vm_container_from(connection)
-      begin
-        connection.serviceInstance.CurrentTime
-      rescue
-        initialize
-      end
+      vsphere_connection_alive? @connection
 
       viewManager = connection.serviceContent.viewManager
       viewManager.CreateContainerView(
@@ -372,6 +385,11 @@ module Vmpooler
       snapshot
     end
 
+    def migrate_vm_host(vm, host)
+      relospec = RbVmomi::VIM.VirtualMachineRelocateSpec(host: host)
+      vm.RelocateVM_Task(spec: relospec).wait_for_completion
+    end
+
     def close
       @connection.close
     end