provisioners/chef: use synced folder cache instead of counter

plugins/provisioners/chef/config/base.rb

@@ -1,11 +1,7 @@
-require "vagrant/util/counter"
-
 module VagrantPlugins
   module Chef
     module Config
       class Base < Vagrant.plugin("2", :config)
-        extend Vagrant::Util::Counter
-
         # The path to Chef's bin/ directory.
         # @return [String]
         attr_accessor :binary_path

plugins/provisioners/chef/config/base_runner.rb

@@ -81,7 +81,7 @@ module VagrantPlugins
           @https_proxy_pass   = nil if @https_proxy_pass == UNSET_VALUE
           @no_proxy           = nil if @no_proxy == UNSET_VALUE
           @node_name          = nil if @node_name == UNSET_VALUE
-          @provisioning_path  = nil if @provisioning_path == UNSET_VALUE
+          @provisioning_path = "/tmp/vagrant-chef" if @provisioning_path == UNSET_VALUE
           @file_backup_path   = "/var/chef/backup" if @file_backup_path == UNSET_VALUE
           @file_cache_path    = "/var/chef/cache"  if @file_cache_path == UNSET_VALUE
           @verbose_logging    = false if @verbose_logging == UNSET_VALUE
@@ -89,12 +89,6 @@ module VagrantPlugins
           if @encrypted_data_bag_secret_key_path == UNSET_VALUE
             @encrypted_data_bag_secret_key_path = nil
           end
-
-          # Set the default provisioning path to be a unique path in /tmp
-          if !@provisioning_path
-            counter = self.class.get_and_update_counter(:chef_config)
-            @provisioning_path = "/tmp/vagrant-chef-#{counter}"
-          end
         end
 
         def merge(other)

plugins/provisioners/chef/provisioner/chef_solo.rb

@@ -1,3 +1,7 @@
+require "digest/md5"
+require "securerandom"
+require "set"
+
 require "log4r"
 
 require "vagrant/util/counter"
@@ -11,6 +15,8 @@ module VagrantPlugins
       class ChefSolo < Base
         extend Vagrant::Util::Counter
         include Vagrant::Util::Counter
+        include Vagrant::Action::Builtin::MixinSyncedFolders
+
         attr_reader :environments_folders
         attr_reader :cookbook_folders
         attr_reader :role_folders
@@ -28,10 +34,11 @@ module VagrantPlugins
           @data_bags_folders = expanded_folders(@config.data_bags_path, "data_bags")
           @environments_folders = expanded_folders(@config.environments_path, "environments")
 
-          share_folders(root_config, "csc", @cookbook_folders)
-          share_folders(root_config, "csr", @role_folders)
-          share_folders(root_config, "csdb", @data_bags_folders)
-          share_folders(root_config, "cse", @environments_folders)
+          existing = synced_folders(@machine, cached: true)
+          share_folders(root_config, "csc", @cookbook_folders, existing)
+          share_folders(root_config, "csr", @role_folders, existing)
+          share_folders(root_config, "csdb", @data_bags_folders, existing)
+          share_folders(root_config, "cse", @environments_folders, existing)
         end
 
         def provision(mode = :solo)
@@ -72,8 +79,10 @@ module VagrantPlugins
               local_path = File.expand_path(path, @machine.env.root_path)
 
               if File.exist?(local_path)
-                # Path exists on the host, setup the remote path
-                remote_path = "#{@config.provisioning_path}/chef-solo-#{get_and_update_counter(:cookbooks_path)}"
+                # Path exists on the host, setup the remote path. We use
+                # the MD5 of the local path so that it is predictable.
+                key         = Digest::MD5.hexdigest(local_path)
+                remote_path = "#{@config.provisioning_path}/#{key}"
               else
                 @machine.ui.warn(I18n.t("vagrant.provisioners.chef.cookbook_folder_not_found_warning",
                                        path: local_path.to_s))
@@ -103,16 +112,31 @@ module VagrantPlugins
 
         # Shares the given folders with the given prefix. The folders should
         # be of the structure resulting from the `expanded_folders` function.
-        def share_folders(root_config, prefix, folders)
+        def share_folders(root_config, prefix, folders, existing=nil)
+          existing_set = Set.new
+          (existing || []).each do |_, fs|
+            fs.each do |id, data|
+              existing_set.add(data[:guestpath])
+            end
+          end
+
           folders.each do |type, local_path, remote_path|
-            if type == :host
+            next if type != :host
+
+            # If this folder already exists, then we don't share it, it means
+            # it was already put down on disk.
+            if existing_set.include?(remote_path)
+              @logger.debug("Not sharing #{local_path}, exists as #{remote_path}")
+              next
+            end
+
             opts = {}
             opts[:id] = "v-#{prefix}-#{self.class.get_and_update_counter(:shared_folder)}"
             opts[:type] = @config.synced_folder_type if @config.synced_folder_type
 
             root_config.vm.synced_folder(local_path, remote_path, opts)
           end
-          end
+
           @shared_folders += folders
         end