`--[no-]parallel` for vagrant up

CHANGELOG.md

@@ -1,5 +1,10 @@
 ## 1.2.1 (unreleased)
 
+FEATURES:
+
+  - Add a `--[no-]parallel` flag to `vagrant up` to enable/disable
+    parallelism. Vagrant will parallelize by default.
+
 IMPROVEMENTS:
 
   - Get rid of arbitrary 4 second sleep when connecting via SSH. The

lib/vagrant/batch_action.rb

@@ -6,9 +6,9 @@ module Vagrant
   # This class executes multiple actions as a single batch, parallelizing
   # the action calls if possible.
   class BatchAction
-    def initialize(disable_parallel=false)
+    def initialize(allow_parallel=true)
       @actions          = []
-      @disable_parallel = disable_parallel
+      @allow_parallel   = allow_parallel
       @logger           = Log4r::Logger.new("vagrant::batch_action")
     end
 
@@ -27,14 +27,14 @@ module Vagrant
     # Run all the queued up actions, parallelizing if possible.
     #
     # This will parallelize if and only if the provider of every machine
-    # supports parallelization. Parallelizing can additionally be disabled
+    # supports parallelization and parallelization is possible from
-    # by passing the option into the initializer of this class.
+    # initialization of the class.
     def run
-      par = true
-
-      if @disable_parallel
       par = false
-        @logger.info("Disabled parallelization by force.")
+
+      if @allow_parallel
+        par = true
+        @logger.info("Enabling parallelization by default.")
       end
 
       if par

lib/vagrant/environment.rb

@@ -197,11 +197,11 @@ module Vagrant
     #
     # This handles the case where batch actions are disabled by the
     # VAGRANT_NO_PARALLEL environmental variable.
-    def batch(disable_parallel=false)
+    def batch(parallel=true)
-      disable_parallel ||= !!ENV["VAGRANT_NO_PARALLEL"]
+      parallel = false if ENV["VAGRANT_NO_PARALLEL"]
 
       @batch_lock.synchronize do
-        BatchAction.new(disable_parallel).tap do |b|
+        BatchAction.new(parallel).tap do |b|
           # Yield it so that the caller can setup actions
           yield b
 

plugins/commands/up/command.rb

@@ -11,12 +11,19 @@ module VagrantPlugins
 
       def execute
         options = {}
+        options[:parallel] = true
+
         opts = OptionParser.new do |o|
-          o.banner = "Usage: vagrant up [vm-name] [--[no-]provision] [--provider provider] [-h]"
+          o.banner = "Usage: vagrant up [vm-name] [options] [-h]"
           o.separator ""
 
           build_start_options(o, options)
 
+          o.on("--[no-]parallel",
+               "Enable or disable parallelism if provider supports it.") do |parallel|
+            options[:parallel] = parallel
+          end
+
           o.on("--provider provider", String,
                "Back the machine with a specific provider.") do |provider|
             options[:provider] = provider
@@ -31,7 +38,7 @@ module VagrantPlugins
         @logger.debug("'Up' each target VM...")
 
         # Build up the batch job of what we'll do
-        @env.batch do |batch|
+        @env.batch(options[:parallel]) do |batch|
           with_target_vms(argv, :provider => options[:provider]) do |machine|
             @env.ui.info(I18n.t(
               "vagrant.commands.up.upping",

test/unit/vagrant/environment_test.rb

@@ -58,7 +58,7 @@ describe Vagrant::Environment do
     context "without the disabling env var" do
       it "should run without disabling parallelization" do
         with_temp_env("VAGRANT_NO_PARALLEL" => nil) do
-          Vagrant::BatchAction.should_receive(:new).with(false).and_return(batch)
+          Vagrant::BatchAction.should_receive(:new).with(true).and_return(batch)
           batch.should_receive(:run)
 
           instance.batch {}
@@ -67,10 +67,10 @@ describe Vagrant::Environment do
 
       it "should run with disabling parallelization if explicit" do
         with_temp_env("VAGRANT_NO_PARALLEL" => nil) do
-          Vagrant::BatchAction.should_receive(:new).with(true).and_return(batch)
+          Vagrant::BatchAction.should_receive(:new).with(false).and_return(batch)
           batch.should_receive(:run)
 
-          instance.batch(true) {}
+          instance.batch(false) {}
         end
       end
     end
@@ -78,7 +78,7 @@ describe Vagrant::Environment do
     context "with the disabling env var" do
       it "should run with disabling parallelization" do
         with_temp_env("VAGRANT_NO_PARALLEL" => "yes") do
-          Vagrant::BatchAction.should_receive(:new).with(true).and_return(batch)
+          Vagrant::BatchAction.should_receive(:new).with(false).and_return(batch)
           batch.should_receive(:run)
 
           instance.batch {}