require 'spec_helper'
require 'time'
require 'mock_redis'

# Custom RSpec :Matchers

# Match a Hashtable['name'] is an expected value
RSpec::Matchers.define :a_pool_with_name_of do |value|
  match { |actual| actual['name'] == value }
end

describe 'Pool Manager' do
  let(:logger) { MockLogger.new }
  let(:redis) { MockRedis.new }
  let(:metrics) { Vmpooler::DummyStatsd.new }
  let(:config) { {} }
  let(:pool) { 'pool1' }
  let(:vm) { 'vm1' }
  let(:timeout) { 5 }
  let(:host) { double('host') }
  let(:token) { 'token1234'}

  subject { Vmpooler::PoolManager.new(config, logger, redis, metrics) }

  describe '#check_pending_vm' do
    let(:vsphere) { double('vsphere') }

    before do
      expect(subject).not_to be_nil
    end

    it 'calls _check_pending_vm' do
      expect(Thread).to receive(:new).and_yield
      expect(subject).to receive(:_check_pending_vm).with(vm,pool,timeout,vsphere)

      subject.check_pending_vm(vm, pool, timeout, vsphere)
    end
  end

  describe '#open_socket' do
    let(:TCPSocket) { double('tcpsocket') }
    let(:socket) { double('tcpsocket') }
    let(:hostname) { 'host' }
    let(:domain) { 'domain.local'}
    let(:default_socket) { 22 }

    before do
      expect(subject).not_to be_nil
      allow(socket).to receive(:close)
    end

    it 'opens socket with defaults' do
      expect(TCPSocket).to receive(:new).with(hostname,default_socket).and_return(socket)

      expect(subject.open_socket(hostname)).to eq(nil)
    end

    it 'yields the socket if a block is given' do
      expect(TCPSocket).to receive(:new).with(hostname,default_socket).and_return(socket)

      expect{ |socket| subject.open_socket(hostname,nil,nil,default_socket,&socket) }.to yield_control.exactly(1).times 
    end

    it 'closes the opened socket' do
      expect(TCPSocket).to receive(:new).with(hostname,default_socket).and_return(socket)
      expect(socket).to receive(:close)

      expect(subject.open_socket(hostname)).to eq(nil)
    end

    it 'opens a specific socket' do
      expect(TCPSocket).to receive(:new).with(hostname,80).and_return(socket)

      expect(subject.open_socket(hostname,nil,nil,80)).to eq(nil)
    end

    it 'uses a specific domain with the hostname' do
      expect(TCPSocket).to receive(:new).with("#{hostname}.#{domain}",default_socket).and_return(socket)

      expect(subject.open_socket(hostname,domain)).to eq(nil)
    end

    it 'raises error if host is not resolvable' do
      expect(TCPSocket).to receive(:new).with(hostname,default_socket).and_raise(SocketError,'getaddrinfo: No such host is known')

      expect { subject.open_socket(hostname,nil,1) }.to raise_error(SocketError)
    end

    it 'raises error if socket is not listening' do
      expect(TCPSocket).to receive(:new).with(hostname,default_socket).and_raise(SocketError,'No connection could be made because the target machine actively refused it')

      expect { subject.open_socket(hostname,nil,1) }.to raise_error(SocketError)
    end
  end

  describe '#_check_pending_vm' do
    let(:vsphere) { double('vsphere') }

    before do
      expect(subject).not_to be_nil
    end

    context 'host does not exist or not in pool' do
      it 'calls fail_pending_vm' do
        expect(vsphere).to receive(:find_vm).and_return(nil)
        expect(subject).to receive(:fail_pending_vm).with(vm, pool, timeout, false) 

        subject._check_pending_vm(vm, pool, timeout, vsphere)
      end
    end

    context 'host is in pool' do
      it 'calls move_pending_vm_to_ready if host is ready' do
        expect(vsphere).to receive(:find_vm).and_return(host)
        expect(subject).to receive(:open_socket).and_return(nil)
        expect(subject).to receive(:move_pending_vm_to_ready).with(vm, pool, host)

        subject._check_pending_vm(vm, pool, timeout, vsphere)
      end

      it 'calls fail_pending_vm if an error is raised' do
        expect(vsphere).to receive(:find_vm).and_return(host)
        expect(subject).to receive(:open_socket).and_raise(SocketError,'getaddrinfo: No such host is known')
        expect(subject).to receive(:fail_pending_vm).with(vm, pool, timeout)

        subject._check_pending_vm(vm, pool, timeout, vsphere)
      end
    end
  end

  describe '#remove_nonexistent_vm' do
    before do
      expect(subject).not_to be_nil
    end

    it 'removes VM from pending in redis' do
      create_pending_vm(pool,vm)

      expect(redis.sismember("vmpooler__pending__#{pool}", vm)).to be(true)
      subject.remove_nonexistent_vm(vm, pool)
      expect(redis.sismember("vmpooler__pending__#{pool}", vm)).to be(false)
    end

    it 'logs msg' do
      expect(logger).to receive(:log).with('d', "[!] [#{pool}] '#{vm}' no longer exists. Removing from pending.")

      subject.remove_nonexistent_vm(vm, pool)
    end
  end

 describe '#fail_pending_vm' do
    before do
      expect(subject).not_to be_nil
    end

    before(:each) do
      create_pending_vm(pool,vm)
    end

    it 'takes no action if VM is not cloning' do
      expect(subject.fail_pending_vm(vm, pool, timeout)).to eq(nil)
      expect(redis.sismember("vmpooler__pending__#{pool}", vm)).to be(true)
    end

    it 'takes no action if VM is within timeout' do
      redis.hset("vmpooler__vm__#{vm}", 'clone',Time.now.to_s)
      expect(subject.fail_pending_vm(vm, pool, timeout)).to eq(nil)
      expect(redis.sismember("vmpooler__pending__#{pool}", vm)).to be(true)
    end

    it 'moves VM to completed queue if VM has exceeded timeout and exists' do
      redis.hset("vmpooler__vm__#{vm}", 'clone',Date.new(2001,1,1).to_s)
      expect(subject.fail_pending_vm(vm, pool, timeout,true)).to eq(nil)
      expect(redis.sismember("vmpooler__pending__#{pool}", vm)).to be(false)
      expect(redis.sismember("vmpooler__completed__#{pool}", vm)).to be(true)
    end

    it 'logs message if VM has exceeded timeout and exists' do
      redis.hset("vmpooler__vm__#{vm}", 'clone',Date.new(2001,1,1).to_s)
      expect(logger).to receive(:log).with('d', "[!] [#{pool}] '#{vm}' marked as 'failed' after #{timeout} minutes")
      expect(subject.fail_pending_vm(vm, pool, timeout,true)).to eq(nil)
    end

    it 'calls remove_nonexistent_vm if VM has exceeded timeout and does not exist' do
      redis.hset("vmpooler__vm__#{vm}", 'clone',Date.new(2001,1,1).to_s)
      expect(subject).to receive(:remove_nonexistent_vm).with(vm, pool)
      expect(subject.fail_pending_vm(vm, pool, timeout,false)).to eq(nil)
    end

    it 'swallows error if an error is raised' do
      redis.hset("vmpooler__vm__#{vm}", 'clone','iamnotparsable_asdate')
      expect(subject.fail_pending_vm(vm, pool, timeout,true)).to eq(nil)
    end

    it 'logs message if an error is raised' do
      redis.hset("vmpooler__vm__#{vm}", 'clone','iamnotparsable_asdate')
      expect(logger).to receive(:log).with('d', String)

      subject.fail_pending_vm(vm, pool, timeout,true)
    end
  end
  
  describe '#move_pending_vm_to_ready' do
    before do
      expect(subject).not_to be_nil
      allow(Socket).to receive(:getaddrinfo)
    end

    before(:each) do
      create_pending_vm(pool,vm)
    end

    context 'when hostname does not match VM name' do
      it 'should not take any action' do
        expect(logger).to receive(:log).exactly(0).times
        expect(Socket).to receive(:getaddrinfo).exactly(0).times

        allow(host).to receive(:summary).and_return( double('summary') )
        allow(host).to receive_message_chain(:summary, :guest).and_return( double('guest') )
        allow(host).to receive_message_chain(:summary, :guest, :hostName).and_return ('different_name')

        subject.move_pending_vm_to_ready(vm, pool, host)
      end
    end

    context 'when hostname matches VM name' do
      before do
        allow(host).to receive(:summary).and_return( double('summary') )
        allow(host).to receive_message_chain(:summary, :guest).and_return( double('guest') )
        allow(host).to receive_message_chain(:summary, :guest, :hostName).and_return (vm)
      end

      it 'should move the VM from pending to ready pool' do
        expect(redis.sismember("vmpooler__pending__#{pool}", vm)).to be(true)
        expect(redis.sismember("vmpooler__ready__#{pool}", vm)).to be(false)
        subject.move_pending_vm_to_ready(vm, pool, host)
        expect(redis.sismember("vmpooler__pending__#{pool}", vm)).to be(false)
        expect(redis.sismember("vmpooler__ready__#{pool}", vm)).to be(true)
      end

      it 'should log a message' do
        expect(logger).to receive(:log).with('s', "[>] [#{pool}] '#{vm}' moved to 'ready' queue")

        subject.move_pending_vm_to_ready(vm, pool, host)
      end

      it 'should set the boot time in redis' do
        redis.hset("vmpooler__vm__#{vm}", 'clone',Time.now.to_s)
        expect(redis.hget('vmpooler__boot__' + Date.today.to_s, pool + ':' + vm)).to be_nil
        subject.move_pending_vm_to_ready(vm, pool, host)
        expect(redis.hget('vmpooler__boot__' + Date.today.to_s, pool + ':' + vm)).to_not be_nil
        # TODO Should we inspect the value to see if it's valid?
      end

      it 'should not determine boot timespan if clone start time not set' do
        expect(redis.hget('vmpooler__boot__' + Date.today.to_s, pool + ':' + vm)).to be_nil
        subject.move_pending_vm_to_ready(vm, pool, host)
        expect(redis.hget('vmpooler__boot__' + Date.today.to_s, pool + ':' + vm)).to eq("") # Possible implementation bug here. Should still be nil here
      end

      it 'should raise error if clone start time is not parsable' do
        redis.hset("vmpooler__vm__#{vm}", 'clone','iamnotparsable_asdate')
        expect{subject.move_pending_vm_to_ready(vm, pool, host)}.to raise_error(/iamnotparsable_asdate/)
      end
    end
  end

  describe '#check_ready_vm' do
    let(:vsphere) { double('vsphere') }
    let(:ttl) { 0 }

    let(:config) {
      YAML.load(<<-EOT
---
:config:
  vm_checktime: 15

EOT
      )
    }

    before(:each) do
      expect(Thread).to receive(:new).and_yield
      create_ready_vm(pool,vm)
    end

    it 'should raise an error if a TTL above zero is specified' do
      expect { subject.check_ready_vm(vm,pool,5,vsphere) }.to raise_error(NameError) # This is an implementation bug
    end

    context 'a VM that does not need to be checked' do
      it 'should do nothing' do
        redis.hset("vmpooler__vm__#{vm}", 'check',Time.now.to_s)
        subject.check_ready_vm(vm, pool, ttl, vsphere)
      end
    end

    context 'a VM that does not exist' do
      before do
        allow(vsphere).to receive(:find_vm).and_return(nil)
      end

      it 'should set the current check timestamp' do
        allow(subject).to receive(:open_socket)
        expect(redis.hget("vmpooler__vm__#{vm}", 'check')).to be_nil
        subject.check_ready_vm(vm, pool, ttl, vsphere)
        expect(redis.hget("vmpooler__vm__#{vm}", 'check')).to_not be_nil
      end

      it 'should log a message' do
        expect(logger).to receive(:log).with('s', "[!] [#{pool}] '#{vm}' not found in vCenter inventory, removed from 'ready' queue")
        allow(subject).to receive(:open_socket)
        subject.check_ready_vm(vm, pool, ttl, vsphere)
      end

      it 'should remove the VM from the ready queue' do
        allow(subject).to receive(:open_socket)
        expect(redis.sismember("vmpooler__ready__#{pool}", vm)).to be(true)
        subject.check_ready_vm(vm, pool, ttl, vsphere)
        expect(redis.sismember("vmpooler__ready__#{pool}", vm)).to be(false)
      end
    end

    context 'a VM that needs to be checked' do
      before(:each) do
        redis.hset("vmpooler__vm__#{vm}", 'check',Date.new(2001,1,1).to_s)

        allow(host).to receive(:summary).and_return( double('summary') )
        allow(host).to receive_message_chain(:summary, :guest).and_return( double('guest') )
        allow(host).to receive_message_chain(:summary, :guest, :hostName).and_return (vm)
        
        allow(vsphere).to receive(:find_vm).and_return(host)
      end

      context 'and is ready' do
        before(:each) do
          allow(host).to receive(:runtime).and_return( double('runtime') )
          allow(host).to receive_message_chain(:runtime, :powerState).and_return('poweredOn')
          allow(host).to receive_message_chain(:summary, :guest, :hostName).and_return (vm)
          allow(subject).to receive(:open_socket).with(vm).and_return(nil)
        end

        it 'should only set the next check interval' do
          subject.check_ready_vm(vm, pool, ttl, vsphere)
        end
      end

      context 'but turned off and name mismatch' do
        before(:each) do
          allow(host).to receive(:runtime).and_return( double('runtime') )
          allow(host).to receive_message_chain(:runtime, :powerState).and_return('poweredOff')
          allow(host).to receive_message_chain(:summary, :guest, :hostName).and_return ('')
          allow(subject).to receive(:open_socket).with(vm).and_raise(SocketError,'getaddrinfo: No such host is known')
        end

        it 'should move the VM to the completed queue multiple times' do
          # There is an implementation bug which attempts the move multiple times
          expect(redis).to receive(:smove).with("vmpooler__ready__#{pool}", "vmpooler__completed__#{pool}", vm).at_least(2).times

          subject.check_ready_vm(vm, pool, ttl, vsphere)
        end

        it 'should move the VM to the completed queue' do
          expect(redis.sismember("vmpooler__ready__#{pool}", vm)).to be(true)
          expect(redis.sismember("vmpooler__completed__#{pool}", vm)).to be(false)
          subject.check_ready_vm(vm, pool, ttl, vsphere)
          expect(redis.sismember("vmpooler__ready__#{pool}", vm)).to be(false)
          expect(redis.sismember("vmpooler__completed__#{pool}", vm)).to be(true)
        end

        it 'should log messages about being powered off, name mismatch and removed from ready queue' do
          expect(logger).to receive(:log).with('d', "[!] [#{pool}] '#{vm}' appears to be powered off, removed from 'ready' queue")
          expect(logger).to receive(:log).with('d', "[!] [#{pool}] '#{vm}' has mismatched hostname, removed from 'ready' queue")

         # There is an implementation bug which attempts the move multiple times however
         # as the VM is no longer in the ready queue, redis also throws an error
         expect(logger).to receive(:log).with("d", "[!] [#{pool}] '#{vm}' is unreachable, and failed to remove from 'ready' queue")

          subject.check_ready_vm(vm, pool, ttl, vsphere)
        end

        it 'should log a message if it fails to move queues' do
          expect(logger).to receive(:log).with('d', "[!] [#{pool}] '#{vm}' appears to be powered off, removed from 'ready' queue")
          expect(logger).to receive(:log).with('d', "[!] [#{pool}] '#{vm}' has mismatched hostname, removed from 'ready' queue")
          expect(logger).to receive(:log).with('d', "[!] [#{pool}] '#{vm}' is unreachable, and failed to remove from 'ready' queue")

          subject.check_ready_vm(vm, pool, ttl, vsphere)
        end
      end
    end
  end

  describe '#check_running_vm' do
    let(:vsphere) { double('vsphere') }
    let (:ttl) { 5 }

    before do
      expect(subject).not_to be_nil
    end

    it 'calls _check_running_vm' do
      expect(Thread).to receive(:new).and_yield
      expect(subject).to receive(:_check_running_vm).with(vm, pool, ttl, vsphere)

      subject.check_running_vm(vm, pool, ttl, vsphere)
    end
  end

  describe '#_check_running_vm' do
    let(:vsphere) { double('vsphere') }

    before do
      expect(subject).not_to be_nil
    end

    before(:each) do
      create_running_vm(pool,vm)
    end

    it 'does nothing with a missing VM' do
      allow(vsphere).to receive(:find_vm).and_return(nil)
      expect(redis.sismember("vmpooler__running__#{pool}", vm)).to be(true)
      subject._check_running_vm(vm, pool, timeout, vsphere)
      expect(redis.sismember("vmpooler__running__#{pool}", vm)).to be(true)
    end

    context 'valid host' do
      let(:vm_host) { double('vmhost') }

     it 'should not move VM when not poweredOn' do
        # I'm not sure this test is useful.  There is no codepath
        # in _check_running_vm that looks at Power State
        allow(vsphere).to receive(:find_vm).and_return vm_host
        allow(vm_host).to receive(:runtime).and_return true
        allow(vm_host).to receive_message_chain(:runtime, :powerState).and_return 'poweredOff'
        expect(logger).not_to receive(:log).with('d', "[!] [#{pool}] '#{vm}' appears to be powered off or dead")
        expect(redis.sismember("vmpooler__running__#{pool}", vm)).to be(true)
        subject._check_running_vm(vm, pool, timeout, vsphere)
        expect(redis.sismember("vmpooler__running__#{pool}", vm)).to be(true)
      end

      it 'should not move VM if it has no checkout time' do
        allow(vsphere).to receive(:find_vm).and_return vm_host
        expect(redis.sismember("vmpooler__running__#{pool}", vm)).to be(true)
        subject._check_running_vm(vm, pool, 0, vsphere)
        expect(redis.sismember("vmpooler__running__#{pool}", vm)).to be(true)
      end

      it 'should not move VM if TTL is zero' do
        allow(vsphere).to receive(:find_vm).and_return vm_host
        redis.hset("vmpooler__active__#{pool}", vm,(Time.now - timeout*60*60).to_s)
        expect(redis.sismember("vmpooler__running__#{pool}", vm)).to be(true)
        subject._check_running_vm(vm, pool, 0, vsphere)
        expect(redis.sismember("vmpooler__running__#{pool}", vm)).to be(true)
      end

      it 'should move VM when past TTL' do
        allow(vsphere).to receive(:find_vm).and_return vm_host
        redis.hset("vmpooler__active__#{pool}", vm,(Time.now - timeout*60*60).to_s)
        expect(redis.sismember("vmpooler__running__#{pool}", vm)).to be(true)
        expect(redis.sismember("vmpooler__completed__#{pool}", vm)).to be(false)
        subject._check_running_vm(vm, pool, timeout, vsphere)
        expect(redis.sismember("vmpooler__running__#{pool}", vm)).to be(false)
        expect(redis.sismember("vmpooler__completed__#{pool}", vm)).to be(true)
      end
    end
  end

  describe '#move_vm_queue' do
    let(:queue_from) { 'pending' }
    let(:queue_to) { 'completed' }
    let(:message) { 'message' }

    before do
      expect(subject).not_to be_nil
    end

    before(:each) do
      create_pending_vm(pool, vm, token)
    end

    it 'VM should be in the "from queue" before the move' do
      expect(redis.sismember("vmpooler__#{queue_from}__#{pool}",vm))
    end

    it 'VM should not be in the "from queue" after the move' do
      subject.move_vm_queue(pool, vm, queue_from, queue_to, message)
      expect(!redis.sismember("vmpooler__#{queue_from}__#{pool}",vm))
    end

    it 'VM should not be in the "to queue" before the move' do
      expect(!redis.sismember("vmpooler__#{queue_to}__#{pool}",vm))
    end

    it 'VM should be in the "to queue" after the move' do
      subject.move_vm_queue(pool, vm, queue_from, queue_to, message)
      expect(redis.sismember("vmpooler__#{queue_to}__#{pool}",vm))
    end

    it 'should log a message' do
      allow(logger).to receive(:log).with('d', "[!] [#{pool}] '#{vm}' #{message}")

      subject.move_vm_queue(pool, vm, queue_from, queue_to, message)
    end
  end

  describe '#clone_vm' do
    before do
      expect(subject).not_to be_nil
    end

    before(:each) do
      expect(Thread).to receive(:new).and_yield
    end

    let(:config) {
      YAML.load(<<-EOT
---
:config:
  prefix: "prefix"
:vsphere:
  username: "vcenter_user"
EOT
      )
    }

    let (:folder) { 'vmfolder' }
    let (:folder_object) { double('folder_object') }
    let (:template_name) { pool }
    let (:template) { "template/#{template_name}" }
    let (:datastore) { 'datastore' }
    let (:target) { 'clone_target' }
    let (:vsphere) { double('vsphere') }
    let (:template_folder_object) { double('template_folder_object') }
    let (:template_vm_object) { double('template_vm_object') }
    let (:clone_task) { double('clone_task') }

    context 'no template specified' do
      it 'should raise an error' do
  
        expect{subject.clone_vm(nil,folder,datastore,target,vsphere)}.to raise_error(/Please provide a full path to the template/)
      end

      it 'should log a message' do
        expect(logger).to receive(:log).with('s', "[!] [] '' failed while preparing to clone with an error: Please provide a full path to the template")

        expect{subject.clone_vm(nil,folder,datastore,target,vsphere)}.to raise_error(RuntimeError)
      end
    end

    context 'a template with no forward slash in the string' do
      it 'should raise an error' do
  
        expect{subject.clone_vm('vm1',folder,datastore,target,vsphere)}.to raise_error(/Please provide a full path to the template/)
      end

      it 'should log a message' do
        expect(logger).to receive(:log).with('s', "[!] [] '' failed while preparing to clone with an error: Please provide a full path to the template")

        expect{subject.clone_vm('vm1',folder,datastore,target,vsphere)}.to raise_error(RuntimeError)
      end
    end

    # Note - It is impossible to get into the following code branch
    # ...
    # if vm['template'].length == 0
    #   fail "Unable to find template '#{vm['template']}'!"
    # end
    # ...

    context "Template name does not match pool name (Implementation Bug)" do
      let (:template_name) { 'template_vm' }

      # The implementaion of clone_vm incorrectly uses the VM Template name instead of the pool name.  The VM Template represents the
      # name of the VM to clone in vSphere whereas pool is the name of the pool in Pooler.  The tests below document the behaviour of
      # clone_vm if the Template and Pool name differ.  It is expected that these test will fail once this bug is removed.

      context 'a valid template' do
        before(:each) do
          expect(template_folder_object).to receive(:find).with(template_name).and_return(template_vm_object)
          expect(vsphere).to receive(:find_folder).with('template').and_return(template_folder_object)
        end

        context 'with no errors during cloning' do
          before(:each) do
            expect(vsphere).to receive(:find_least_used_host).with(target).and_return('least_used_host')
            expect(vsphere).to receive(:find_datastore).with(datastore).and_return('datastore')
            expect(vsphere).to receive(:find_folder).with('vmfolder').and_return(folder_object)
            expect(template_vm_object).to receive(:CloneVM_Task).and_return(clone_task)
            expect(clone_task).to receive(:wait_for_completion)
            expect(metrics).to receive(:timing).with(/clone\./,/0/)
          end

          it 'should create a cloning VM' do
            expect(logger).to receive(:log).at_least(:once)
            expect(redis.scard("vmpooler__pending__#{pool}")).to eq(0)

            subject.clone_vm(template,folder,datastore,target,vsphere)

            expect(redis.scard("vmpooler__pending__#{template_name}")).to eq(1)
            # Get the new VM Name from the pending pool queue as it should be the only entry
            vm_name = redis.smembers("vmpooler__pending__#{template_name}")[0]
            expect(redis.hget("vmpooler__vm__#{vm_name}", 'clone')).to_not be_nil
            expect(redis.hget("vmpooler__vm__#{vm_name}", 'template')).to eq(template_name)
            expect(redis.hget("vmpooler__clone__#{Date.today.to_s}", "#{template_name}:#{vm_name}")).to_not be_nil
            expect(redis.hget("vmpooler__vm__#{vm_name}", 'clone_time')).to_not be_nil
          end

          it 'should log a message that is being cloned from a template' do
            expect(logger).to receive(:log).with('d',/\[ \] \[#{template_name}\] '(.+)' is being cloned from '#{template_name}'/)
            allow(logger).to receive(:log)

            subject.clone_vm(template,folder,datastore,target,vsphere)
          end

          it 'should log a message that it completed being cloned' do
            expect(logger).to receive(:log).with('s',/\[\+\] \[#{template_name}\] '(.+)' cloned from '#{template_name}' in [0-9.]+ seconds/)
            allow(logger).to receive(:log)

            subject.clone_vm(template,folder,datastore,target,vsphere)
          end
        end

        # An error can be cause by the following configuration errors:
        # - Missing or invalid datastore
        # - Missing or invalid clone target
        # also any runtime errors during the cloning process
        # https://www.vmware.com/support/developer/converter-sdk/conv50_apireference/vim.VirtualMachine.html#clone
        context 'with an error during cloning' do
          before(:each) do
            expect(vsphere).to receive(:find_least_used_host).with(target).and_return('least_used_host')
            expect(vsphere).to receive(:find_datastore).with(datastore).and_return(nil)
            expect(vsphere).to receive(:find_folder).with('vmfolder').and_return(folder_object)
            expect(template_vm_object).to receive(:CloneVM_Task).and_return(clone_task)
            expect(clone_task).to receive(:wait_for_completion).and_raise(RuntimeError,'SomeError')
            expect(metrics).to receive(:timing).with(/clone\./,/0/).exactly(0).times

          end

          it 'should raise an error within the Thread' do
            expect(logger).to receive(:log).at_least(:once)
            expect{subject.clone_vm(template,folder,datastore,target,vsphere)}.to raise_error(/SomeError/)
          end

          it 'should log a message that is being cloned from a template' do
            expect(logger).to receive(:log).with('d',/\[ \] \[#{template_name}\] '(.+)' is being cloned from '#{template_name}'/)
            allow(logger).to receive(:log)

            # Swallow the error
            begin
              subject.clone_vm(template,folder,datastore,target,vsphere)
            rescue
            end
          end

          it 'should log messages that the clone failed' do
            expect(logger).to receive(:log).with('s', /\[!\] \[#{template_name}\] '(.+)' clone failed with an error: SomeError/)
            expect(logger).to receive(:log).with('s', /\[!\] \[#{template_name}\] '(.+)' failed while preparing to clone with an error: SomeError/)
            allow(logger).to receive(:log)

            # Swallow the error
            begin
              subject.clone_vm(template,folder,datastore,target,vsphere)
            rescue
            end
          end
        end
      end
    end

    context 'a valid template' do
      before(:each) do
        expect(template_folder_object).to receive(:find).with(template_name).and_return(template_vm_object)
        expect(vsphere).to receive(:find_folder).with('template').and_return(template_folder_object)
      end

      context 'with no errors during cloning' do
        before(:each) do
          expect(vsphere).to receive(:find_least_used_host).with(target).and_return('least_used_host')
          expect(vsphere).to receive(:find_datastore).with(datastore).and_return('datastore')
          expect(vsphere).to receive(:find_folder).with('vmfolder').and_return(folder_object)
          expect(template_vm_object).to receive(:CloneVM_Task).and_return(clone_task)
          expect(clone_task).to receive(:wait_for_completion)
          expect(metrics).to receive(:timing).with(/clone\./,/0/)
        end

        it 'should create a cloning VM' do
          expect(logger).to receive(:log).at_least(:once)
          expect(redis.scard("vmpooler__pending__#{pool}")).to eq(0)

          subject.clone_vm(template,folder,datastore,target,vsphere)

          expect(redis.scard("vmpooler__pending__#{pool}")).to eq(1)
          # Get the new VM Name from the pending pool queue as it should be the only entry
          vm_name = redis.smembers("vmpooler__pending__#{pool}")[0]
          expect(redis.hget("vmpooler__vm__#{vm_name}", 'clone')).to_not be_nil
          expect(redis.hget("vmpooler__vm__#{vm_name}", 'template')).to eq(template_name)
          expect(redis.hget("vmpooler__clone__#{Date.today.to_s}", "#{pool}:#{vm_name}")).to_not be_nil
          expect(redis.hget("vmpooler__vm__#{vm_name}", 'clone_time')).to_not be_nil
        end

        it 'should decrement the clone tasks counter' do
          redis.incr('vmpooler__tasks__clone')
          redis.incr('vmpooler__tasks__clone')
          expect(redis.get('vmpooler__tasks__clone')).to eq('2')
          subject.clone_vm(template,folder,datastore,target,vsphere)
          expect(redis.get('vmpooler__tasks__clone')).to eq('1')
        end

        it 'should log a message that is being cloned from a template' do
          expect(logger).to receive(:log).with('d',/\[ \] \[#{pool}\] '(.+)' is being cloned from '#{template_name}'/)
          allow(logger).to receive(:log)

          subject.clone_vm(template,folder,datastore,target,vsphere)
        end

        it 'should log a message that it completed being cloned' do
          expect(logger).to receive(:log).with('s',/\[\+\] \[#{pool}\] '(.+)' cloned from '#{template_name}' in [0-9.]+ seconds/)
          allow(logger).to receive(:log)

          subject.clone_vm(template,folder,datastore,target,vsphere)
        end
      end

      # An error can be cause by the following configuration errors:
      # - Missing or invalid datastore
      # - Missing or invalid clone target
      # also any runtime errors during the cloning process
      # https://www.vmware.com/support/developer/converter-sdk/conv50_apireference/vim.VirtualMachine.html#clone
      context 'with an error during cloning' do
        before(:each) do
          expect(vsphere).to receive(:find_least_used_host).with(target).and_return('least_used_host')
          expect(vsphere).to receive(:find_datastore).with(datastore).and_return(nil)
          expect(vsphere).to receive(:find_folder).with('vmfolder').and_return(folder_object)
          expect(template_vm_object).to receive(:CloneVM_Task).and_return(clone_task)
          expect(clone_task).to receive(:wait_for_completion).and_raise(RuntimeError,'SomeError')
          expect(metrics).to receive(:timing).with(/clone\./,/0/).exactly(0).times

        end

        it 'should raise an error within the Thread' do
          expect(logger).to receive(:log).at_least(:once)
          expect{subject.clone_vm(template,folder,datastore,target,vsphere)}.to raise_error(/SomeError/)
        end

        it 'should log a message that is being cloned from a template' do
          expect(logger).to receive(:log).with('d',/\[ \] \[#{pool}\] '(.+)' is being cloned from '#{template_name}'/)
          allow(logger).to receive(:log)

          # Swallow the error
          begin
            subject.clone_vm(template,folder,datastore,target,vsphere)
          rescue
          end
        end

        it 'should log messages that the clone failed' do
          expect(logger).to receive(:log).with('s', /\[!\] \[#{pool}\] '(.+)' clone failed with an error: SomeError/)
          expect(logger).to receive(:log).with('s', /\[!\] \[#{pool}\] '(.+)' failed while preparing to clone with an error: SomeError/)
          allow(logger).to receive(:log)

          # Swallow the error
          begin
            subject.clone_vm(template,folder,datastore,target,vsphere)
          rescue
          end
        end
      end
    end
  end

  describe "#destroy_vm" do
    let (:vsphere) { double('vsphere') }

    let(:config) {
      YAML.load(<<-EOT
---
:redis:
  data_ttl: 168
EOT
      )
    }

    before do
      expect(subject).not_to be_nil
    end

    before(:each) do
      expect(Thread).to receive(:new).and_yield

      create_completed_vm(vm,pool,true)
    end

    context 'when redis data_ttl is not specified in the configuration' do
      let(:config) {
        YAML.load(<<-EOT
---
:redis:
  "key": "value"
EOT
      )
      }

      before(:each) do
        expect(vsphere).to receive(:find_vm).and_return(nil)
      end

      it 'should call redis expire with 0' do
        expect(redis.hget("vmpooler__vm__#{vm}", 'checkout')).to_not be_nil
        subject.destroy_vm(vm,pool,vsphere)
        expect(redis.hget("vmpooler__vm__#{vm}", 'checkout')).to be_nil
      end
    end

    context 'when there is no redis section in the configuration' do
      let(:config) {}
      
      it 'should raise an error' do
        expect{ subject.destroy_vm(vm,pool,vsphere) }.to raise_error(NoMethodError)
      end
    end

    context 'when a VM does not exist' do
      before(:each) do
        expect(vsphere).to receive(:find_vm).and_return(nil)
      end

      it 'should not call any vsphere methods' do
        subject.destroy_vm(vm,pool,vsphere)
      end
    end

    context 'when a VM exists' do
      let (:destroy_task) { double('destroy_task') }
      let (:poweroff_task) { double('poweroff_task') }

      before(:each) do
        expect(vsphere).to receive(:find_vm).and_return(host)
        allow(host).to receive(:runtime).and_return(true)
      end

      context 'and an error occurs during destroy' do
        before(:each) do
          allow(host).to receive_message_chain(:runtime, :powerState).and_return('poweredOff')
          expect(host).to receive(:Destroy_Task).and_return(destroy_task)
          expect(destroy_task).to receive(:wait_for_completion).and_raise(RuntimeError,'DestroyFailure')
          expect(metrics).to receive(:timing).exactly(0).times
        end

        it 'should raise an error in the thread' do
          expect { subject.destroy_vm(vm,pool,vsphere) }.to raise_error(/DestroyFailure/)
        end
      end

      context 'and an error occurs during power off' do
        before(:each) do
          allow(host).to receive_message_chain(:runtime, :powerState).and_return('poweredOn')
          expect(host).to receive(:PowerOffVM_Task).and_return(poweroff_task)
          expect(poweroff_task).to receive(:wait_for_completion).and_raise(RuntimeError,'PowerOffFailure')
          expect(logger).to receive(:log).with('d', "[ ] [#{pool}] '#{vm}' is being shut down")
          expect(metrics).to receive(:timing).exactly(0).times
        end

        it 'should raise an error in the thread' do
          expect { subject.destroy_vm(vm,pool,vsphere) }.to raise_error(/PowerOffFailure/)
        end
      end

      context 'and is powered off' do
        before(:each) do
          allow(host).to receive_message_chain(:runtime, :powerState).and_return('poweredOff')
          expect(host).to receive(:Destroy_Task).and_return(destroy_task)
          expect(destroy_task).to receive(:wait_for_completion)
          expect(metrics).to receive(:timing).with("destroy.#{pool}", /0/)
        end

        it 'should log a message the VM was destroyed' do
          expect(logger).to receive(:log).with('s', /\[-\] \[#{pool}\] '#{vm}' destroyed in [0-9.]+ seconds/)
          subject.destroy_vm(vm,pool,vsphere)
        end
      end

      context 'and is powered on' do
        before(:each) do
          allow(host).to receive_message_chain(:runtime, :powerState).and_return('poweredOn')
          expect(host).to receive(:Destroy_Task).and_return(destroy_task)
          expect(host).to receive(:PowerOffVM_Task).and_return(poweroff_task)
          expect(poweroff_task).to receive(:wait_for_completion)
          expect(destroy_task).to receive(:wait_for_completion)
          expect(metrics).to receive(:timing).with("destroy.#{pool}", /0/)
        end

        it 'should log a message the VM is being shutdown' do
          expect(logger).to receive(:log).with('d', "[ ] [#{pool}] '#{vm}' is being shut down")
          allow(logger).to receive(:log)

          subject.destroy_vm(vm,pool,vsphere)
        end

        it 'should log a message the VM was destroyed' do
         expect(logger).to receive(:log).with('s', /\[-\] \[#{pool}\] '#{vm}' destroyed in [0-9.]+ seconds/)
          allow(logger).to receive(:log)

          subject.destroy_vm(vm,pool,vsphere)
        end
      end
    end
  end

  describe '#create_vm_disk' do
    let(:vsphere) { double('vsphere') }
    let(:disk_size) { 15 }

    before do
      expect(subject).not_to be_nil
    end

    it 'calls _create_vm_disk' do
      expect(Thread).to receive(:new).and_yield
      expect(subject).to receive(:_create_vm_disk).with(vm, disk_size, vsphere)

      subject.create_vm_disk(vm, disk_size, vsphere)
    end
  end

  describe "#_create_vm_disk" do
    let(:vsphere) { double('vsphere') }
    let(:disk_size) { '15' }
    let(:datastore) { 'datastore0'}
    let(:config) {
      YAML.load(<<-EOT
---
:pools:
  - name: #{pool}
    datastore: '#{datastore}'
EOT
      )
    }

    before do
      expect(subject).not_to be_nil
    end

    before(:each) do
      allow(vsphere).to receive(:find_vm).with(vm).and_return(host)
      create_running_vm(pool,vm,token)
    end

    it 'should not do anything if the VM does not exist' do
      expect(vsphere).to receive(:find_vm).with(vm).and_return(nil)
      expect(logger).to receive(:log).exactly(0).times
      subject._create_vm_disk(vm, disk_size, vsphere)
    end

    it 'should not do anything if the disk size is nil' do
      expect(logger).to receive(:log).exactly(0).times
      subject._create_vm_disk(vm, nil, vsphere)
    end

    it 'should not do anything if the disk size is empty string' do
      expect(logger).to receive(:log).exactly(0).times
      subject._create_vm_disk(vm, '', vsphere)
    end

    it 'should not do anything if the disk size is less than 1' do
      expect(logger).to receive(:log).exactly(0).times
      subject._create_vm_disk(vm, '0', vsphere)
    end

    it 'should not do anything if the disk size cannot be converted to an integer' do
      expect(logger).to receive(:log).exactly(0).times
      subject._create_vm_disk(vm, 'abc123', vsphere)
    end

    it 'should raise an error if the disk size is a Fixnum' do
      expect(logger).to receive(:log).exactly(0).times
      expect{ subject._create_vm_disk(vm, 10, vsphere) }.to raise_error(NoMethodError,/empty?/)
    end

    it 'should not do anything if the datastore for pool is nil' do
      expect(logger).to receive(:log).with('s', "[ ] [disk_manager] '#{vm}' is attaching a #{disk_size}gb disk")
      expect(logger).to receive(:log).with('s', "[+] [disk_manager] '#{vm}' failed to attach disk")
      config[:pools][0]['datastore'] = nil

      subject._create_vm_disk(vm, disk_size, vsphere)
    end

    it 'should not do anything if the datastore for pool is empty' do
      expect(logger).to receive(:log).with('s', "[ ] [disk_manager] '#{vm}' is attaching a #{disk_size}gb disk")
      expect(logger).to receive(:log).with('s', "[+] [disk_manager] '#{vm}' failed to attach disk")
      config[:pools][0]['datastore'] = ''

      subject._create_vm_disk(vm, disk_size, vsphere)
    end

    it 'should attach the disk' do
      expect(logger).to receive(:log).with('s', "[ ] [disk_manager] '#{vm}' is attaching a #{disk_size}gb disk")
      expect(logger).to receive(:log).with('s', /\[\+\] \[disk_manager\] '#{vm}' attached #{disk_size}gb disk in 0.[\d]+ seconds/)
      expect(vsphere).to receive(:add_disk).with(host,disk_size,datastore)

      subject._create_vm_disk(vm, disk_size, vsphere)
    end

    it 'should update redis information when attaching the first disk' do
      expect(vsphere).to receive(:add_disk).with(host,disk_size,datastore)

      subject._create_vm_disk(vm, disk_size, vsphere)
      expect(redis.hget("vmpooler__vm__#{vm}", 'disk')).to eq("+#{disk_size}gb")
    end

    it 'should update redis information when attaching the additional disks' do
      expect(vsphere).to receive(:add_disk).with(host,disk_size,datastore)
      initial_disks = '+10gb:+20gb'
      redis.hset("vmpooler__vm__#{vm}", 'disk', initial_disks)

      subject._create_vm_disk(vm, disk_size, vsphere)
      expect(redis.hget("vmpooler__vm__#{vm}", 'disk')).to eq("#{initial_disks}:+#{disk_size}gb")
    end
  end

  describe '#create_vm_snapshot' do
    let(:vsphere) { double('vsphere') }
    let(:snapshot_name) { 'snapshot' }

    before do
      expect(subject).not_to be_nil
    end

    it 'calls _create_vm_snapshot' do
      expect(Thread).to receive(:new).and_yield
      expect(subject).to receive(:_create_vm_snapshot).with(vm, snapshot_name, vsphere)

      subject.create_vm_snapshot(vm, snapshot_name, vsphere)
    end
  end

  describe '#revert_vm_snapshot' do
    let(:vsphere) { double('vsphere') }
    let(:snapshot_name) { 'snapshot' }

    before do
      expect(subject).not_to be_nil
    end

    it 'calls _create_vm_snapshot' do
      expect(Thread).to receive(:new).and_yield
      expect(subject).to receive(:_revert_vm_snapshot).with(vm, snapshot_name, vsphere)

      subject.revert_vm_snapshot(vm, snapshot_name, vsphere)
    end
  end

  describe '#check_disk_queue' do
    let(:threads) {[]}

    before(:each) do
      expect(Thread).to receive(:new).and_yield
      allow(subject).to receive(:_check_disk_queue)
    end

    it 'should log the disk manager is starting' do
      expect(logger).to receive(:log).with('d', "[*] [disk_manager] starting worker thread")

      expect($threads.count).to be(0)
      subject.check_disk_queue(1,0)
      expect($threads.count).to be(1)
    end

    it 'should add the manager to the global thread list' do
      # Note - Ruby core types are not necessarily thread safe
      expect($threads.count).to be(0)
      subject.check_disk_queue(1,0)
      expect($threads.count).to be(1)
    end

    it 'should call _check_disk_queue' do
      expect(subject).to receive(:_check_disk_queue).with(Vmpooler::VsphereHelper)

      subject.check_disk_queue(1,0)
    end

    context 'delays between loops' do
      let(:maxloop) { 2 }
      let(:loop_delay) { 1 }
      # Note a maxloop of zero can not be tested as it never terminates

      it 'defaults to 5 second loop delay' do
        expect(subject).to receive(:sleep).with(5).exactly(maxloop).times
        subject.check_disk_queue(maxloop)
      end

      it 'when a non-default loop delay is specified' do
        start_time = Time.now
        subject.check_disk_queue(maxloop,loop_delay)
        finish_time = Time.now

        # Use a generous delta to take into account various CPU load etc.
        expect(finish_time - start_time).to be_within(0.75).of(maxloop * loop_delay)
      end
    end

    context 'loops specified number of times (5)' do
      let(:maxloop) { 5 }
      # Note a maxloop of zero can not be tested as it never terminates

      after(:each) do
        # Reset the global variable - Note this is a code smell
        $threads = nil
      end

      it 'should call _check_disk_queue 5 times' do
        expect(subject).to receive(:_check_disk_queue).with(Vmpooler::VsphereHelper).exactly(maxloop).times

        subject.check_disk_queue(maxloop,0)
      end
    end
  end

  describe '#_check_disk_queue' do
    let(:vsphere) { double('vsphere') }

    before do
      expect(subject).not_to be_nil
    end

    context 'when no VMs in the queue' do
      it 'should not call create_vm_disk' do
        expect(subject).to receive(:create_vm_disk).exactly(0).times
        subject._check_disk_queue(vsphere)
      end
    end

    context 'when multiple VMs in the queue' do
      before(:each) do
        disk_task_vm('vm1',1)
        disk_task_vm('vm2',2)
        disk_task_vm('vm3',3)
      end

      it 'should call create_vm_disk once' do
        expect(subject).to receive(:create_vm_disk).exactly(1).times
        subject._check_disk_queue(vsphere)
      end

      it 'should snapshot the first VM in the queue' do
        expect(subject).to receive(:create_vm_disk).with('vm1','1',vsphere)
        subject._check_disk_queue(vsphere)
      end

      it 'should log an error if one occurs' do
        expect(subject).to receive(:create_vm_disk).and_raise(RuntimeError,'MockError')
        expect(logger).to receive(:log).with('s', "[!] [disk_manager] disk creation appears to have failed")
        subject._check_disk_queue(vsphere)
      end
    end
  end

  describe '#check_snapshot_queue' do
    let(:threads) {[]}

    before(:each) do
      expect(Thread).to receive(:new).and_yield
      allow(subject).to receive(:_check_snapshot_queue)
    end

    it 'should log the disk manager is starting' do
      expect(logger).to receive(:log).with('d', "[*] [snapshot_manager] starting worker thread")

      expect($threads.count).to be(0)
      subject.check_snapshot_queue(1,0)
      expect($threads.count).to be(1)
    end

    it 'should add the manager to the global thread list' do
      # Note - Ruby core types are not necessarily thread safe
      expect($threads.count).to be(0)
      subject.check_snapshot_queue(1,0)
      expect($threads.count).to be(1)
    end

    it 'should call _check_snapshot_queue' do
      expect(subject).to receive(:_check_snapshot_queue).with(Vmpooler::VsphereHelper)

      subject.check_snapshot_queue(1,0)
    end

    context 'delays between loops' do
      let(:maxloop) { 2 }
      let(:loop_delay) { 1 }
      # Note a maxloop of zero can not be tested as it never terminates

      it 'defaults to 5 second loop delay' do
        expect(subject).to receive(:sleep).with(5).exactly(maxloop).times
        subject.check_snapshot_queue(maxloop)
      end

      it 'when a non-default loop delay is specified' do
        start_time = Time.now
        subject.check_snapshot_queue(maxloop,loop_delay)
        finish_time = Time.now

        # Use a generous delta to take into account various CPU load etc.
        expect(finish_time - start_time).to be_within(0.75).of(maxloop * loop_delay)
      end
    end

    context 'loops specified number of times (5)' do
      let(:maxloop) { 5 }
      # Note a maxloop of zero can not be tested as it never terminates

      after(:each) do
        # Reset the global variable - Note this is a code smell
        $threads = nil
      end

      it 'should call _check_snapshot_queue 5 times' do
        expect(subject).to receive(:_check_snapshot_queue).with(Vmpooler::VsphereHelper).exactly(maxloop).times

        subject.check_snapshot_queue(maxloop,0)
      end
    end
  end

  describe '#_check_snapshot_queue' do
    let(:vsphere) { double('vsphere') }

    before do
      expect(subject).not_to be_nil
    end

    context 'vmpooler__tasks__snapshot queue' do
      context 'when no VMs in the queue' do
        it 'should not call create_vm_snapshot' do
          expect(subject).to receive(:create_vm_snapshot).exactly(0).times
          subject._check_snapshot_queue(vsphere)
        end
      end

      context 'when multiple VMs in the queue' do
        before(:each) do
          snapshot_vm('vm1','snapshot1')
          snapshot_vm('vm2','snapshot2')
          snapshot_vm('vm3','snapshot3')
        end

        it 'should call create_vm_snapshot once' do
          expect(subject).to receive(:create_vm_snapshot).exactly(1).times
          subject._check_snapshot_queue(vsphere)
        end

        it 'should snapshot the first VM in the queue' do
          expect(subject).to receive(:create_vm_snapshot).with('vm1','snapshot1',vsphere)
          subject._check_snapshot_queue(vsphere)
        end

        it 'should log an error if one occurs' do
          expect(subject).to receive(:create_vm_snapshot).and_raise(RuntimeError,'MockError')
          expect(logger).to receive(:log).with('s', "[!] [snapshot_manager] snapshot appears to have failed")
          subject._check_snapshot_queue(vsphere)
        end
      end
    end

    context 'revert_vm_snapshot queue' do
      context 'when no VMs in the queue' do
        it 'should not call revert_vm_snapshot' do
          expect(subject).to receive(:revert_vm_snapshot).exactly(0).times
          subject._check_snapshot_queue(vsphere)
        end
      end

      context 'when multiple VMs in the queue' do
        before(:each) do
          snapshot_revert_vm('vm1','snapshot1')
          snapshot_revert_vm('vm2','snapshot2')
          snapshot_revert_vm('vm3','snapshot3')
        end

        it 'should call revert_vm_snapshot once' do
          expect(subject).to receive(:revert_vm_snapshot).exactly(1).times
          subject._check_snapshot_queue(vsphere)
        end

        it 'should revert snapshot the first VM in the queue' do
          expect(subject).to receive(:revert_vm_snapshot).with('vm1','snapshot1',vsphere)
          subject._check_snapshot_queue(vsphere)
        end

        it 'should log an error if one occurs' do
          expect(subject).to receive(:revert_vm_snapshot).and_raise(RuntimeError,'MockError')
          expect(logger).to receive(:log).with('s', "[!] [snapshot_manager] snapshot revert appears to have failed")
          subject._check_snapshot_queue(vsphere)
        end
      end
    end
  end


  describe '#migration_limit' do
    # This is a little confusing.  Is this supposed to return a boolean
    # or integer type?
    [false,0].each do |testvalue|
      it "should return false for an input of #{testvalue}" do
        expect(subject.migration_limit(testvalue)).to eq(false)
      end
    end

    [1,32768].each do |testvalue|
      it "should return #{testvalue} for an input of #{testvalue}" do
        expect(subject.migration_limit(testvalue)).to eq(testvalue)
      end
    end

    [-1,-32768].each do |testvalue|
      it "should return nil for an input of #{testvalue}" do
        expect(subject.migration_limit(testvalue)).to be_nil
      end
    end
  end

  describe '#migrate_vm' do
    let(:vsphere) { double('vsphere') }

    before do
      expect(subject).not_to be_nil
    end

    it 'calls _migrate_vm' do
      expect(Thread).to receive(:new).and_yield
      expect(subject).to receive(:_migrate_vm).with(vm, pool, vsphere)

      subject.migrate_vm(vm, pool, vsphere)
    end
  end

  describe "#get_vm_host_info" do
    before do
      expect(subject).not_to be_nil
    end

    let(:vm_object) { double('vm_object') }
    let(:parent_host) { double('parent_host') }

    it 'should return an array with host information' do
      expect(vm_object).to receive_message_chain(:summary, :runtime, :host).and_return(parent_host)
      expect(parent_host).to receive(:name).and_return('vmhostname')

      expect(subject.get_vm_host_info(vm_object)).to eq([parent_host,'vmhostname'])
    end
  end

  describe "#execute!" do
    let(:threads) {{}}

    let(:config) {
      YAML.load(<<-EOT
---
:pools:
  - name: #{pool}
EOT
      )
    }

    let(:thread) { double('thread') }

    before do
      expect(subject).not_to be_nil
    end

    context 'on startup' do
      before(:each) do
        allow(subject).to receive(:check_disk_queue)
        allow(subject).to receive(:check_snapshot_queue)
        allow(subject).to receive(:check_pool)
        expect(logger).to receive(:log).with('d', 'starting vmpooler')
      end

      it 'should set clone tasks to zero' do
        redis.set('vmpooler__tasks__clone', 1)
        subject.execute!(1,0)
        expect(redis.get('vmpooler__tasks__clone')).to eq('0')
      end

      it 'should clear migration tasks' do
        redis.set('vmpooler__migration', 1)
        subject.execute!(1,0)
        expect(redis.get('vmpooler__migration')).to be_nil
      end

      it 'should run the check_disk_queue method' do
        expect(subject).to receive(:check_disk_queue)

        subject.execute!(1,0)
      end

      it 'should run the check_snapshot_queue method' do
        expect(subject).to receive(:check_snapshot_queue)

        subject.execute!(1,0)
      end

      it 'should check the pools in the config' do
        expect(subject).to receive(:check_pool).with(a_pool_with_name_of(pool))

        subject.execute!(1,0)
      end
    end

    context 'with dead disk_manager thread' do
      before(:each) do
        allow(subject).to receive(:check_snapshot_queue)
        allow(subject).to receive(:check_pool)
        expect(logger).to receive(:log).with('d', 'starting vmpooler')
      end

      after(:each) do
        # Reset the global variable - Note this is a code smell
        $threads = nil
      end

      it 'should run the check_disk_queue method and log a message' do
        expect(thread).to receive(:alive?).and_return(false)
        expect(subject).to receive(:check_disk_queue)
        expect(logger).to receive(:log).with('d', "[!] [disk_manager] worker thread died, restarting")
        $threads['disk_manager'] = thread

        subject.execute!(1,0)
      end
    end

    context 'with dead snapshot_manager thread' do
      before(:each) do
        allow(subject).to receive(:check_disk_queue)
        allow(subject).to receive(:check_pool)
        expect(logger).to receive(:log).with('d', 'starting vmpooler')
      end

      after(:each) do
        # Reset the global variable - Note this is a code smell
        $threads = nil
      end

      it 'should run the check_snapshot_queue method and log a message' do
        expect(thread).to receive(:alive?).and_return(false)
        expect(subject).to receive(:check_snapshot_queue)
        expect(logger).to receive(:log).with('d', "[!] [snapshot_manager] worker thread died, restarting")
        $threads['snapshot_manager'] = thread

        subject.execute!(1,0)
      end
    end

    context 'with dead pool thread' do
      before(:each) do
        allow(subject).to receive(:check_disk_queue)
        allow(subject).to receive(:check_snapshot_queue)
        expect(logger).to receive(:log).with('d', 'starting vmpooler')
      end

      after(:each) do
        # Reset the global variable - Note this is a code smell
        $threads = nil
      end

      it 'should run the check_pool method and log a message' do
        expect(thread).to receive(:alive?).and_return(false)
        expect(subject).to receive(:check_pool).with(a_pool_with_name_of(pool))
        expect(logger).to receive(:log).with('d', "[!] [#{pool}] worker thread died, restarting")
        $threads[pool] = thread

        subject.execute!(1,0)
      end
    end

    context 'delays between loops' do
      let(:maxloop) { 2 }
      let(:loop_delay) { 1 }
      # Note a maxloop of zero can not be tested as it never terminates
      before(:each) do
  
        allow(subject).to receive(:check_disk_queue)
        allow(subject).to receive(:check_snapshot_queue)
        allow(subject).to receive(:check_pool)
      end

      it 'when a non-default loop delay is specified' do
        start_time = Time.now
        subject.execute!(maxloop,loop_delay)
        finish_time = Time.now

        # Use a generous delta to take into account various CPU load etc.
        expect(finish_time - start_time).to be_within(0.75).of(maxloop * loop_delay)
      end
    end

    context 'loops specified number of times (5)' do
      let(:maxloop) { 5 }
      # Note a maxloop of zero can not be tested as it never terminates
      before(:each) do
        end

      after(:each) do
        # Reset the global variable - Note this is a code smell
        $threads = nil
      end

      it 'should run startup tasks only once' do
        allow(subject).to receive(:check_disk_queue)
        allow(subject).to receive(:check_snapshot_queue)
        allow(subject).to receive(:check_pool)

        subject.execute!(maxloop,0)
      end

      it 'should run per thread tasks 5 times when threads are not remembered' do
        expect(subject).to receive(:check_disk_queue).exactly(maxloop).times
        expect(subject).to receive(:check_snapshot_queue).exactly(maxloop).times
        expect(subject).to receive(:check_pool).exactly(maxloop).times

        subject.execute!(maxloop,0)
      end

      it 'should not run per thread tasks when threads are alive' do
        expect(subject).to receive(:check_disk_queue).exactly(0).times
        expect(subject).to receive(:check_snapshot_queue).exactly(0).times
        expect(subject).to receive(:check_pool).exactly(0).times

        allow(thread).to receive(:alive?).and_return(true)
        $threads[pool] = thread
        $threads['disk_manager'] = thread
        $threads['snapshot_manager'] = thread

        subject.execute!(maxloop,0)
      end
    end
  end

 describe "#check_pool" do
    let(:threads) {{}}
    let(:vsphere) {{}}

    let(:config) {
      YAML.load(<<-EOT
---
:pools:
  - name: #{pool}
EOT
      )
    }

    let(:thread) { double('thread') }
    let(:pool_object) { config[:pools][0] }

    before do
      expect(subject).not_to be_nil
      expect(Thread).to receive(:new).and_yield
    end

    context 'on startup' do
      before(:each) do
        # Note the Vmpooler::VsphereHelper is not mocked
        allow(subject).to receive(:_check_pool)        
        expect(logger).to receive(:log).with('d', "[*] [#{pool}] starting worker thread")
      end

      after(:each) do
        # Reset the global variable - Note this is a code smell
        $threads = nil
        $vsphere = nil
      end

      it 'should log a message the worker thread is starting' do
        subject.check_pool(pool_object,1,0)
      end

      it 'should populate the vsphere global variable' do
        subject.check_pool(pool_object,1,0)

        expect($vsphere[pool]).to_not be_nil 
      end

      it 'should populate the threads global variable' do
        subject.check_pool(pool_object,1,0)

        # Unable to test for nil as the Thread is mocked
        expect($threads.keys.include?(pool))
      end
    end

    context 'delays between loops' do
      let(:maxloop) { 2 }
      let(:loop_delay) { 1 }
      # Note a maxloop of zero can not be tested as it never terminates

      before(:each) do
        allow(logger).to receive(:log)
        # Note the Vmpooler::VsphereHelper is not mocked
        allow(subject).to receive(:_check_pool)        
      end

      after(:each) do
        # Reset the global variable - Note this is a code smell
        $threads = nil
        $vsphere = nil
      end

      it 'when a non-default loop delay is specified' do
        start_time = Time.now
        subject.check_pool(pool_object,maxloop,loop_delay)
        finish_time = Time.now

        # Use a generous delta to take into account various CPU load etc.
        expect(finish_time - start_time).to be_within(0.75).of(maxloop * loop_delay)
      end
    end

    context 'loops specified number of times (5)' do
      let(:maxloop) { 5 }
      # Note a maxloop of zero can not be tested as it never terminates
      before(:each) do
        allow(logger).to receive(:log)
        # Note the Vmpooler::VsphereHelper is not mocked
        allow(subject).to receive(:_check_pool)        
      end

      after(:each) do
        # Reset the global variable - Note this is a code smell
        $threads = nil
        $vsphere = nil
      end

      it 'should run startup tasks only once' do
        expect(logger).to receive(:log).with('d', "[*] [#{pool}] starting worker thread")

        subject.check_pool(pool_object,maxloop,0)
      end

      it 'should run per thread tasks 5 times' do
        expect(subject).to receive(:_check_pool).exactly(maxloop).times

        subject.check_pool(pool_object,maxloop,0)
      end
    end
  end

  describe '#remove_vmpooler_migration_vm' do
    before do
      expect(subject).not_to be_nil
    end

    it 'should remove the migration from redis' do
      redis.sadd('vmpooler__migration', vm)
      expect(redis.sismember('vmpooler__migration',vm)).to be(true)
      subject.remove_vmpooler_migration_vm(pool, vm)
      expect(redis.sismember('vmpooler__migration',vm)).to be(false)
    end

    it 'should log a message and swallow an error if one occurs' do
      expect(redis).to receive(:srem).and_raise(RuntimeError,'MockError')
      expect(logger).to receive(:log).with('s', "[x] [#{pool}] '#{vm}' removal from vmpooler__migration failed with an error: MockError")
      subject.remove_vmpooler_migration_vm(pool, vm)
    end
  end

  describe '#migrate_vm_and_record_timing' do
    let(:vsphere) { double('vsphere') }
    let(:vm_object) { double('vm_object') }
    let(:source_host_name) { 'source_host' }
    let(:dest_host_name) { 'dest_host' }

    before do
      expect(subject).not_to be_nil
    end

    before(:each) do
      create_vm(vm,token)
      expect(vsphere).to receive(:migrate_vm_host).with(vm_object, host)
    end

    it 'should return the elapsed time for the migration' do
      result = subject.migrate_vm_and_record_timing(vm_object, vm, pool, host, source_host_name, dest_host_name, vsphere)
      expect(result).to match(/0\.[\d]+/)
    end

    it 'should add timing metric' do
      expect(metrics).to receive(:timing).with("migrate.#{pool}",String)
      subject.migrate_vm_and_record_timing(vm_object, vm, pool, host, source_host_name, dest_host_name, vsphere)
    end

    it 'should increment from_host and to_host metric' do
      expect(metrics).to receive(:increment).with("migrate_from.#{source_host_name}")
      expect(metrics).to receive(:increment).with("migrate_to.#{dest_host_name}")
      subject.migrate_vm_and_record_timing(vm_object, vm, pool, host, source_host_name, dest_host_name, vsphere)
    end

    it 'should set migration_time metric in redis' do
      expect(redis.hget("vmpooler__vm__#{vm}", 'migration_time')).to be_nil
      subject.migrate_vm_and_record_timing(vm_object, vm, pool, host, source_host_name, dest_host_name, vsphere)
      expect(redis.hget("vmpooler__vm__#{vm}", 'migration_time')).to match(/0\.[\d]+/)
    end

    it 'should set checkout_to_migration metric in redis' do
      expect(redis.hget("vmpooler__vm__#{vm}", 'checkout_to_migration')).to be_nil
      subject.migrate_vm_and_record_timing(vm_object, vm, pool, host, source_host_name, dest_host_name, vsphere)
      expect(redis.hget("vmpooler__vm__#{vm}", 'checkout_to_migration')).to match(/0\.[\d]+/)
    end
  end

  describe '#_check_pool' do
    # Default test fixtures will consist of;
    #   - Empty Redis dataset
    #   - A single pool with a pool size of zero i.e. no new VMs should be created
    #   - Task limit of 10
    let(:config) {
      YAML.load(<<-EOT
---
:config:
  task_limit: 10
:pools:
  - name: #{pool}
    folder: 'vm_folder'
    size: 0
EOT
      )
    }
    let(:pool_object) { config[:pools][0] }
    let(:vsphere) { double('vsphere') }
    let(:new_vm) { 'newvm'}

    before do
      expect(subject).not_to be_nil
      allow(logger).to receive(:log).with("s", "[!] [#{pool}] is empty")
    end

    # INVENTORY
    context 'Conducting inventory' do
      before(:each) do
        allow(subject).to receive(:migrate_vm)
        allow(subject).to receive(:check_running_vm)
        allow(subject).to receive(:check_ready_vm)
        allow(subject).to receive(:check_pending_vm)
        allow(subject).to receive(:destroy_vm)
        allow(subject).to receive(:clone_vm)
      end

      it 'should log an error if one occurs' do
        expect(vsphere).to receive(:find_folder).and_raise(RuntimeError,'Mock Error')
        expect(logger).to receive(:log).with('s', "[!] [#{pool}] _check_pool failed with an error while inspecting inventory: Mock Error")

        subject._check_pool(pool_object,vsphere)
      end

      it 'should log the discovery of VMs' do
        expect(vsphere).to receive(:find_folder).and_return(MockFindFolder.new([new_vm]))
        expect(logger).to receive(:log).with('s', "[?] [#{pool}] '#{new_vm}' added to 'discovered' queue")

        subject._check_pool(pool_object,vsphere)
      end

      it 'should add undiscovered VMs to the completed queue' do
        expect(vsphere).to receive(:find_folder).and_return(MockFindFolder.new([new_vm]))
        allow(logger).to receive(:log).with('s', "[?] [#{pool}] '#{new_vm}' added to 'discovered' queue")

        expect(redis.sismember("vmpooler__discovered__#{pool}", new_vm)).to be(false)
        expect(redis.sismember("vmpooler__completed__#{pool}", new_vm)).to be(false)

        subject._check_pool(pool_object,vsphere)

        expect(redis.sismember("vmpooler__discovered__#{pool}", new_vm)).to be(false)
        expect(redis.sismember("vmpooler__completed__#{pool}", new_vm)).to be(true)
      end

      ['running','ready','pending','completed','discovered','migrating'].each do |queue_name|
        it "should not discover VMs in the #{queue_name} queue" do
          expect(vsphere).to receive(:find_folder).and_return(MockFindFolder.new([new_vm]))

          expect(logger).to receive(:log).with('s', "[?] [#{pool}] '#{new_vm}' added to 'discovered' queue").exactly(0).times
          expect(redis.sismember("vmpooler__discovered__#{pool}", new_vm)).to be(false)
          redis.sadd("vmpooler__#{queue_name}__#{pool}", new_vm)

          subject._check_pool(pool_object,vsphere)

          if queue_name == 'discovered'
            # Discovered VMs end up in the completed queue
            expect(redis.sismember("vmpooler__completed__#{pool}", new_vm)).to be(true)
          else
            expect(redis.sismember("vmpooler__#{queue_name}__#{pool}", new_vm)).to be(true)
          end
        end
      end
    end

    # RUNNING
    context 'Running VM not in the inventory' do
      before(:each) do
        expect(vsphere).to receive(:find_folder).and_return(MockFindFolder.new([new_vm]))
        expect(logger).to receive(:log).with('s', "[?] [#{pool}] '#{new_vm}' added to 'discovered' queue")
        create_running_vm(pool,vm,token)
      end

      it 'should not do anything' do
        expect(subject).to receive(:check_running_vm).exactly(0).times

        subject._check_pool(pool_object,vsphere)
      end
    end

    context 'Running VM in the inventory' do
      before(:each) do
        expect(vsphere).to receive(:find_folder).and_return(MockFindFolder.new([vm]))
        allow(subject).to receive(:check_running_vm)
        create_running_vm(pool,vm,token)
      end

      it 'should log an error if one occurs' do
        expect(subject).to receive(:check_running_vm).and_raise(RuntimeError,'MockError')
        expect(logger).to receive(:log).with('d', "[!] [#{pool}] _check_pool with an error while evaluating running VMs: MockError")

        subject._check_pool(pool_object,vsphere)
      end

      it 'should use the VM lifetime in preference to defaults' do
        big_lifetime = 2000

        redis.hset("vmpooler__vm__#{vm}", 'lifetime',big_lifetime)
        # The lifetime comes in as string
        expect(subject).to receive(:check_running_vm).with(vm,pool,"#{big_lifetime}",vsphere)

        subject._check_pool(pool_object,vsphere)
      end

      it 'should use the configuration default if the VM lifetime is not set' do
        config[:config]['vm_lifetime'] = 50
        expect(subject).to receive(:check_running_vm).with(vm,pool,50,vsphere)

        subject._check_pool(pool_object,vsphere)
      end

      it 'should use a lifetime of 12 if nothing is set' do
        expect(subject).to receive(:check_running_vm).with(vm,pool,12,vsphere)

        subject._check_pool(pool_object,vsphere)
      end
    end

    # READY
    context 'Ready VM not in the inventory' do
      before(:each) do
        expect(vsphere).to receive(:find_folder).and_return(MockFindFolder.new([new_vm]))
        expect(logger).to receive(:log).with('s', "[?] [#{pool}] '#{new_vm}' added to 'discovered' queue")
        create_ready_vm(pool,vm,token)
      end

      it 'should not do anything' do
        expect(subject).to receive(:check_ready_vm).exactly(0).times

        subject._check_pool(pool_object,vsphere)
      end
    end

    context 'Ready VM in the inventory' do
      before(:each) do
        expect(vsphere).to receive(:find_folder).and_return(MockFindFolder.new([vm]))
        allow(subject).to receive(:check_ready_vm)
        create_ready_vm(pool,vm,token)
      end

      it 'should log an error if one occurs' do
        expect(subject).to receive(:check_ready_vm).and_raise(RuntimeError,'MockError')
        expect(logger).to receive(:log).with('d', "[!] [#{pool}] _check_pool failed with an error while evaluating ready VMs: MockError")

        subject._check_pool(pool_object,vsphere)
      end

      it 'should use the pool TTL if set' do
        big_lifetime = 2000

        config[:pools][0]['ready_ttl'] = big_lifetime
        expect(subject).to receive(:check_ready_vm).with(vm,pool,big_lifetime,vsphere)

        subject._check_pool(pool_object,vsphere)
      end

      it 'should use a pool TTL of zero if none set' do
        expect(subject).to receive(:check_ready_vm).with(vm,pool,0,vsphere)

        subject._check_pool(pool_object,vsphere)
      end
    end

    # PENDING
    context 'Pending VM not in the inventory' do
      before(:each) do
        expect(vsphere).to receive(:find_folder).and_return(MockFindFolder.new([new_vm]))
        expect(logger).to receive(:log).with('s', "[?] [#{pool}] '#{new_vm}' added to 'discovered' queue")
        create_pending_vm(pool,vm,token)
      end

      it 'should call fail_pending_vm' do
        expect(subject).to receive(:check_ready_vm).exactly(0).times
        expect(subject).to receive(:fail_pending_vm).with(vm,pool,Integer,false)

        subject._check_pool(pool_object,vsphere)
      end
    end

    context 'Pending VM in the inventory' do
      before(:each) do
        expect(vsphere).to receive(:find_folder).and_return(MockFindFolder.new([vm]))
        allow(subject).to receive(:check_pending_vm)
        create_pending_vm(pool,vm,token)
      end

      it 'should log an error if one occurs' do
        expect(subject).to receive(:check_pending_vm).and_raise(RuntimeError,'MockError')
        expect(logger).to receive(:log).with('d', "[!] [#{pool}] _check_pool failed with an error while evaluating pending VMs: MockError")

        subject._check_pool(pool_object,vsphere)
      end

      it 'should use the pool timeout if set' do
        big_lifetime = 2000

        config[:pools][0]['timeout'] = big_lifetime
        expect(subject).to receive(:check_pending_vm).with(vm,pool,big_lifetime,vsphere)

        subject._check_pool(pool_object,vsphere)
      end

      it 'should use the configuration setting if the pool timeout is not set' do
        big_lifetime = 2000

        config[:config]['timeout'] = big_lifetime
        expect(subject).to receive(:check_pending_vm).with(vm,pool,big_lifetime,vsphere)

        subject._check_pool(pool_object,vsphere)
      end

      it 'should use a pool timeout of 15 if nothing is set' do
        expect(subject).to receive(:check_pending_vm).with(vm,pool,15,vsphere)

        subject._check_pool(pool_object,vsphere)
      end
    end

    # COMPLETED
    context 'Completed VM not in the inventory' do
      before(:each) do
        expect(vsphere).to receive(:find_folder).and_return(MockFindFolder.new([new_vm]))
        expect(logger).to receive(:log).with('s', "[?] [#{pool}] '#{new_vm}' added to 'discovered' queue")
        expect(logger).to receive(:log).with('s', "[!] [#{pool}] '#{vm}' not found in inventory, removed from 'completed' queue")
        create_completed_vm(vm,pool,true)
      end

      it 'should log a message' do
        subject._check_pool(pool_object,vsphere)
      end

      it 'should not call destroy_vm' do
        expect(subject).to receive(:destroy_vm).exactly(0).times

        subject._check_pool(pool_object,vsphere)
      end

      it 'should remove redis information' do
        expect(redis.sismember("vmpooler__completed__#{pool}",vm)).to be(true)
        expect(redis.hget("vmpooler__vm__#{vm}", 'checkout')).to_not be(nil)
        expect(redis.hget("vmpooler__active__#{pool}",vm)).to_not be(nil)

        subject._check_pool(pool_object,vsphere)

        expect(redis.sismember("vmpooler__completed__#{pool}",vm)).to be(false)
        expect(redis.hget("vmpooler__vm__#{vm}", 'checkout')).to be(nil)
        expect(redis.hget("vmpooler__active__#{pool}",vm)).to be(nil)
      end
    end

    context 'Completed VM in the inventory' do
      before(:each) do
        expect(vsphere).to receive(:find_folder).and_return(MockFindFolder.new([vm]))
        create_completed_vm(vm,pool,true)
      end

      it 'should call destroy_vm' do
        expect(subject).to receive(:destroy_vm)

        subject._check_pool(pool_object,vsphere)
      end

      context 'with an error during destroy_vm' do
        before(:each) do
          expect(subject).to receive(:destroy_vm).and_raise(RuntimeError,"MockError")
          expect(logger).to receive(:log).with('d', "[!] [#{pool}] _check_pool failed with an error while evaluating completed VMs: MockError")
        end

        it 'should log a message' do
          subject._check_pool(pool_object,vsphere)
        end

        it 'should remove redis information' do
          expect(redis.sismember("vmpooler__completed__#{pool}",vm)).to be(true)
          expect(redis.hget("vmpooler__vm__#{vm}", 'checkout')).to_not be(nil)
          expect(redis.hget("vmpooler__active__#{pool}",vm)).to_not be(nil)

          subject._check_pool(pool_object,vsphere)

          expect(redis.sismember("vmpooler__completed__#{pool}",vm)).to be(false)
          expect(redis.hget("vmpooler__vm__#{vm}", 'checkout')).to be(nil)
          expect(redis.hget("vmpooler__active__#{pool}",vm)).to be(nil)
        end
      end
    end

    # DISCOVERED
    context 'Discovered VM' do
      before(:each) do
        expect(vsphere).to receive(:find_folder).and_return(MockFindFolder.new([vm]))
        create_discovered_vm(vm,pool)
      end

      it 'should be moved to the completed queue' do
        subject._check_pool(pool_object,vsphere)

        expect(redis.sismember("vmpooler__completed__#{pool}", vm)).to be(true)
      end

      it 'should log a message if an error occurs' do
        expect(redis).to receive(:smove).with("vmpooler__discovered__#{pool}", "vmpooler__completed__#{pool}", vm).and_raise(RuntimeError,'MockError')
        expect(logger).to receive(:log).with("d", "[!] [#{pool}] _check_pool failed with an error while evaluating discovered VMs: MockError")

        subject._check_pool(pool_object,vsphere)
      end

      ['pending','ready','running','completed'].each do |queue_name|
        context "exists in the #{queue_name} queue" do
          before(:each) do
            allow(subject).to receive(:migrate_vm)
            allow(subject).to receive(:check_running_vm)
            allow(subject).to receive(:check_ready_vm)
            allow(subject).to receive(:check_pending_vm)
            allow(subject).to receive(:destroy_vm)
            allow(subject).to receive(:clone_vm)
          end

          it "should remain in the #{queue_name} queue" do
            redis.sadd("vmpooler__#{queue_name}__#{pool}", vm)
            allow(logger).to receive(:log)

            subject._check_pool(pool_object,vsphere)

            expect(redis.sismember("vmpooler__#{queue_name}__#{pool}", vm)).to be(true)
          end

          it "should be removed from the discovered queue" do
            redis.sadd("vmpooler__#{queue_name}__#{pool}", vm)
            allow(logger).to receive(:log)

            expect(redis.sismember("vmpooler__discovered__#{pool}", vm)).to be(true)
            subject._check_pool(pool_object,vsphere)
            expect(redis.sismember("vmpooler__discovered__#{pool}", vm)).to be(false)
          end

          it "should log a message" do
            redis.sadd("vmpooler__#{queue_name}__#{pool}", vm)
            expect(logger).to receive(:log).with('d', "[!] [#{pool}] '#{vm}' found in '#{queue_name}', removed from 'discovered' queue")

            subject._check_pool(pool_object,vsphere)
          end
        end
      end
    end

    # MIGRATIONS
    context 'Migrating VM not in the inventory' do
      before(:each) do
        expect(vsphere).to receive(:find_folder).and_return(MockFindFolder.new([new_vm]))
        expect(logger).to receive(:log).with('s', "[?] [#{pool}] '#{new_vm}' added to 'discovered' queue")
        create_migrating_vm(vm,pool)
      end

      it 'should not do anything' do
        expect(subject).to receive(:migrate_vm).exactly(0).times

        subject._check_pool(pool_object,vsphere)
      end
    end

    context 'Migrating VM in the inventory' do
      before(:each) do
        expect(vsphere).to receive(:find_folder).and_return(MockFindFolder.new([vm]))
        allow(subject).to receive(:check_ready_vm)
        allow(logger).to receive(:log).with("s", "[!] [#{pool}] is empty")
        create_migrating_vm(vm,pool)
      end

      it 'should log an error if one occurs' do
        expect(subject).to receive(:migrate_vm).and_raise(RuntimeError,'MockError')
        expect(logger).to receive(:log).with('s', "[x] [#{pool}] '#{vm}' failed to migrate: MockError")

        subject._check_pool(pool_object,vsphere)
      end

      it 'should call migrate_vm' do
        expect(subject).to receive(:migrate_vm).with(vm,pool,vsphere)

        subject._check_pool(pool_object,vsphere)
      end
    end

    # REPOPULATE
    context 'Repopulate a pool' do
      it 'should not call clone_vm when number of VMs is equal to the pool size' do
        expect(vsphere).to receive(:find_folder).and_return(MockFindFolder.new([]))
        expect(subject).to receive(:clone_vm).exactly(0).times

        subject._check_pool(pool_object,vsphere)
      end

      it 'should not call clone_vm when number of VMs is greater than the pool size' do
        expect(vsphere).to receive(:find_folder).and_return(MockFindFolder.new([vm]))
        create_ready_vm(pool,vm,token)
        expect(subject).to receive(:clone_vm).exactly(0).times

        subject._check_pool(pool_object,vsphere)
      end

      ['ready','pending'].each do |queue_name|
        it "should use VMs in #{queue_name} queue to caculate pool size" do
          expect(vsphere).to receive(:find_folder).and_return(MockFindFolder.new([vm]))
          expect(subject).to receive(:clone_vm).exactly(0).times
          # Modify the pool size to 1 and add a VM in the queue
          redis.sadd("vmpooler__#{queue_name}__#{pool}",vm)
          config[:pools][0]['size'] = 1
          
          subject._check_pool(pool_object,vsphere)
        end
      end

      ['running','completed','discovered','migrating'].each do |queue_name|
        it "should not use VMs in #{queue_name} queue to caculate pool size" do
          expect(vsphere).to receive(:find_folder).and_return(MockFindFolder.new([vm]))
          expect(subject).to receive(:clone_vm)
          # Modify the pool size to 1 and add a VM in the queue
          redis.sadd("vmpooler__#{queue_name}__#{pool}",vm)
          config[:pools][0]['size'] = 1

          subject._check_pool(pool_object,vsphere)
        end
      end

      it 'should log a message the first time a pool is empty' do
        expect(vsphere).to receive(:find_folder).and_return(MockFindFolder.new([]))
        expect(logger).to receive(:log).with('s', "[!] [#{pool}] is empty")

        subject._check_pool(pool_object,vsphere)
      end

      context 'when pool is marked as empty' do
        before(:each) do
          expect(vsphere).to receive(:find_folder).and_return(MockFindFolder.new([]))
          redis.set("vmpooler__empty__#{pool}", 'true')
        end

        it 'should not log a message when the pool remains empty' do
          expect(logger).to receive(:log).with('s', "[!] [#{pool}] is empty").exactly(0).times

          subject._check_pool(pool_object,vsphere)
        end

        it 'should remove the empty pool mark if it is no longer empty' do
          create_ready_vm(pool,vm,token)

          expect(redis.get("vmpooler__empty__#{pool}")).to be_truthy
          subject._check_pool(pool_object,vsphere)
          expect(redis.get("vmpooler__empty__#{pool}")).to be_falsey
        end
      end

      context 'when number of VMs is less than the pool size' do
        before(:each) do
          expect(vsphere).to receive(:find_folder).and_return(MockFindFolder.new([]))
        end

        it 'should call clone_vm to populate the pool' do
          pool_size = 5
          config[:pools][0]['size'] = pool_size

          expect(subject).to receive(:clone_vm).exactly(pool_size).times
          
          subject._check_pool(pool_object,vsphere)
        end

        it 'should call clone_vm until task_limit is hit' do
          task_limit = 2
          pool_size = 5
          config[:pools][0]['size'] = pool_size
          config[:config]['task_limit'] = task_limit

          expect(subject).to receive(:clone_vm).exactly(task_limit).times
          
          subject._check_pool(pool_object,vsphere)
        end

        it 'log a message if a cloning error occurs' do
          pool_size = 1
          config[:pools][0]['size'] = pool_size

          expect(subject).to receive(:clone_vm).and_raise(RuntimeError,"MockError")
          expect(logger).to receive(:log).with("s", "[!] [#{pool}] clone failed during check_pool with an error: MockError")
          expect(logger).to receive(:log).with('d', "[!] [#{pool}] _check_pool failed with an error: MockError")
          
          expect{ subject._check_pool(pool_object,vsphere) }.to raise_error(RuntimeError,'MockError')
        end
      end

      context 'export metrics' do
        it 'increments metrics for ready queue' do
          create_ready_vm(pool,'vm1')
          create_ready_vm(pool,'vm2')
          create_ready_vm(pool,'vm3')
          expect(vsphere).to receive(:find_folder).and_return(MockFindFolder.new(['vm1','vm2','vm3']))

          expect(metrics).to receive(:gauge).with("ready.#{pool}", 3)
          allow(metrics).to receive(:gauge)

          subject._check_pool(pool_object,vsphere)
        end

        it 'increments metrics for running queue' do
          create_running_vm(pool,'vm1',token)
          create_running_vm(pool,'vm2',token)
          create_running_vm(pool,'vm3',token)
          expect(vsphere).to receive(:find_folder).and_return(MockFindFolder.new(['vm1','vm2','vm3']))

          expect(metrics).to receive(:gauge).with("running.#{pool}", 3)
          allow(metrics).to receive(:gauge)

          subject._check_pool(pool_object,vsphere)
        end

        it 'increments metrics with 0 when pool empty' do
          expect(vsphere).to receive(:find_folder).and_return(MockFindFolder.new([]))

          expect(metrics).to receive(:gauge).with("ready.#{pool}", 0)
          expect(metrics).to receive(:gauge).with("running.#{pool}", 0)

          subject._check_pool(pool_object,vsphere)
        end
      end
    end
  end

  describe '#_create_vm_snapshot' do
    let(:snapshot_manager) { 'snapshot_manager' }
    let(:pool_helper) { double('snapshot_manager') }
    let(:vsphere) { {snapshot_manager => pool_helper} }

    before do
      expect(subject).not_to be_nil
      $vsphere = vsphere
    end

    context '(valid host)' do
      let(:vm_host) { double('vmhost') }

      it 'creates a snapshot' do
        expect(vsphere).to receive(:find_vm).and_return vm_host
        expect(logger).to receive(:log)
        expect(vm_host).to receive_message_chain(:CreateSnapshot_Task, :wait_for_completion)
        expect(redis).to receive(:hset).with('vmpooler__vm__testvm', 'snapshot:testsnapshot', Time.now.to_s)
        expect(logger).to receive(:log)

        subject._create_vm_snapshot('testvm', 'testsnapshot', vsphere)
      end
    end
  end

  describe '#_revert_vm_snapshot' do
    let(:snapshot_manager) { 'snapshot_manager' }
    let(:pool_helper) { double('snapshot_manager') }
    let(:vsphere) { {snapshot_manager => pool_helper} }

    before do
      expect(subject).not_to be_nil
      $vsphere = vsphere
    end

    context '(valid host)' do
      let(:vm_host) { double('vmhost') }
      let(:vm_snapshot) { double('vmsnapshot') }

      it 'reverts a snapshot' do
        expect(vsphere).to receive(:find_vm).and_return vm_host
        expect(vsphere).to receive(:find_snapshot).and_return vm_snapshot
        expect(logger).to receive(:log)
        expect(vm_snapshot).to receive_message_chain(:RevertToSnapshot_Task, :wait_for_completion)
        expect(logger).to receive(:log)

        subject._revert_vm_snapshot('testvm', 'testsnapshot', vsphere)
      end
    end
  end

  describe '#_check_snapshot_queue' do
    let(:pool_helper) { double('pool') }
    let(:vsphere) { {pool => pool_helper} }

    before do
      expect(subject).not_to be_nil
      $vsphere = vsphere
    end

    it 'checks appropriate redis queues' do
      expect(redis).to receive(:spop).with('vmpooler__tasks__snapshot')
      expect(redis).to receive(:spop).with('vmpooler__tasks__snapshot-revert')

      subject._check_snapshot_queue(vsphere)
    end
  end
end