(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.

lib/vmpooler/pool_manager.rb

@@ -287,6 +287,54 @@ module Vmpooler
       end
     end
 
+    def purge_unused_vms_and_folders
+      global_purge = $config[:config]['purge_unconfigured_folders']
+      providers = $config[:providers].keys
+      providers.each do |provider|
+        provider_purge = $config[:providers][provider]['purge_unconfigured_folders']
+        provider_purge = global_purge if provider_purge.nil?
+        if provider_purge
+          Thread.new do
+            begin
+              purge_vms_and_folders($providers[provider.to_s])
+            rescue => err
+              $logger.log('s', "[!] failed while purging provider #{provider.to_s} VMs and folders with an error: #{err}")
+            end
+          end
+        end
+      end
+      return
+    end
+
+    # Return a list of pool folders
+    def pool_folders(provider)
+      provider_name = provider.name
+      folders = {}
+      $config[:pools].each do |pool|
+        next unless pool['provider'] == provider_name
+        folder_parts = pool['folder'].split('/')
+        datacenter = provider.get_target_datacenter_from_config(pool['name'])
+        folders[folder_parts.pop] = "#{datacenter}/vm/#{folder_parts.join('/')}"
+      end
+      folders
+    end
+
+    def get_base_folders(folders)
+      base = []
+      folders.each do |key, value|
+        base << value
+      end
+      base.uniq
+    end
+
+    def purge_vms_and_folders(provider)
+      provider_name = provider.name
+      configured_folders = pool_folders(provider)
+      base_folders = get_base_folders(configured_folders)
+      whitelist = $config[:providers][provider_name.to_sym]['folder_whitelist']
+      provider.purge_unconfigured_folders(base_folders, configured_folders, whitelist)
+    end
+
     def create_vm_disk(pool_name, vm, disk_size, provider)
       Thread.new do
         begin
@@ -961,6 +1009,8 @@ module Vmpooler
         end
       end
 
+      purge_unused_vms_and_folders
+
       loop_count = 1
       loop do
         if !$threads['disk_manager']