(POOLER-66) Purge vms and folders no longer configured

This commit enables optional purging for vms and folders when they are
not configured in the vmpooler provided configuration. Base folders are
determined from folders specified in the pool configuration. Then,
anything not configured in that folder for that provider and is not a
whitelisted folder title will be destroyed. Without this change vmpooler
will leave unconfigured vms and folders behind and any vms will be left
running forever without manual intervention. Additionally, any
associated redis data will never be expired.

spec/unit/pool_manager_spec.rb

@@ -802,6 +802,140 @@ EOT
     end
   end
 
+  describe '#purge_unused_vms_and_folders' do
+    let(:config) { YAML.load(<<-EOT
+---
+:config: {}
+:providers:
+  :mock: {}
+:pools:
+  - name: '#{pool}'
+    size: 1
+EOT
+      )
+    }
+
+    it 'should return when purging is not enabled' do
+      expect(subject.purge_unused_vms_and_folders).to be_nil
+    end
+
+    context 'with purging enabled globally' do
+      before(:each) do
+        config[:config]['purge_unconfigured_folders'] = true
+        expect(Thread).to receive(:new).and_yield
+      end
+
+      it 'should run a purge for each provider' do
+        expect(subject).to receive(:purge_vms_and_folders)
+
+        subject.purge_unused_vms_and_folders
+      end
+
+      it 'should log when purging fails' do
+        expect(subject).to receive(:purge_vms_and_folders).and_raise(RuntimeError,'MockError')
+        expect(logger).to receive(:log).with('s', '[!] failed while purging provider mock VMs and folders with an error: MockError')
+
+        subject.purge_unused_vms_and_folders
+      end
+    end
+
+    context 'with purging enabled on the provider' do
+      before(:each) do
+        config[:providers][:mock]['purge_unconfigured_folders'] = true
+        expect(Thread).to receive(:new).and_yield
+      end
+
+      it 'should run a purge for the provider' do
+        expect(subject).to receive(:purge_vms_and_folders)
+
+        subject.purge_unused_vms_and_folders
+      end
+    end
+  end
+
+  describe '#pool_folders' do
+    let(:folder_name) { 'myinstance' }
+    let(:folder_base) { 'vmpooler' }
+    let(:folder) { [folder_base,folder_name].join('/') }
+    let(:datacenter) { 'dc1' }
+    let(:provider_name) { 'mock_provider' }
+    let(:expected_response) {
+      {
+        folder_name => "#{datacenter}/vm/#{folder_base}"
+      }
+    }
+    let(:config) { YAML.load(<<-EOT
+---
+:providers:
+  :mock:
+:pools:
+  - name: '#{pool}'
+    folder: '#{folder}'
+    size: 1
+    datacenter: '#{datacenter}'
+    provider: '#{provider_name}'
+  - name: '#{pool}2'
+    folder: '#{folder}'
+    size: 1
+    datacenter: '#{datacenter}'
+    provider: '#{provider_name}2'
+EOT
+      )
+    }
+
+    it 'should return a list of pool folders' do
+      expect(provider).to receive(:get_target_datacenter_from_config).with(pool).and_return(datacenter)
+
+      expect(subject.pool_folders(provider)).to eq(expected_response)
+    end
+
+    it 'should raise an error when the provider fails to get the datacenter' do
+      expect(provider).to receive(:get_target_datacenter_from_config).with(pool).and_raise('mockerror')
+
+      expect{ subject.pool_folders(provider) }.to raise_error(RuntimeError, 'mockerror')
+    end
+  end
+
+  describe '#purge_vms_and_folders' do
+    let(:folder_name) { 'myinstance' }
+    let(:folder_base) { 'vmpooler' }
+    let(:datacenter) { 'dc1' }
+    let(:full_folder_path) { "#{datacenter}/vm/folder_base" }
+    let(:configured_folders) { { folder_name => full_folder_path } }
+    let(:base_folders) { [ full_folder_path ] }
+    let(:folder) { [folder_base,folder_name].join('/') }
+    let(:provider_name) { 'mock_provider' }
+    let(:whitelist) { nil }
+    let(:config) { YAML.load(<<-EOT
+---
+:config: {}
+:providers:
+  :mock_provider: {}
+:pools:
+  - name: '#{pool}'
+    folder: '#{folder}'
+    size: 1
+    datacenter: '#{datacenter}'
+    provider: '#{provider_name}'
+EOT
+      )
+    }
+
+    it 'should run purge_unconfigured_folders' do
+      expect(subject).to receive(:pool_folders).and_return(configured_folders)
+      expect(provider).to receive(:purge_unconfigured_folders).with(base_folders, configured_folders, whitelist)
+
+      subject.purge_vms_and_folders(provider)
+    end
+
+    it 'should raise any errors' do
+      expect(subject).to receive(:pool_folders).and_return(configured_folders)
+      expect(provider).to receive(:purge_unconfigured_folders).with(base_folders, configured_folders, whitelist).and_raise('mockerror')
+
+      expect{ subject.purge_vms_and_folders(provider) }.to raise_error(RuntimeError, 'mockerror')
+    end
+  end
+
   describe '#create_vm_disk' do
     let(:provider) { double('provider') }
     let(:disk_size) { 15 }
@@ -2080,6 +2214,8 @@ EOT
         let(:config) {
         YAML.load(<<-EOT
 ---
+:providers:
+  :vsphere: {}
 :pools:
   - name: #{pool}
   - name: 'dummy'