Upgrade V1-style dotfile to V2

See the code and comments for details on how this is done. As usual, we
are very careful about this so as not to inadvertently destruct real
user data.

lib/vagrant/environment.rb

@@ -1,4 +1,5 @@
 require 'fileutils'
+require 'json'
 require 'pathname'
 require 'set'
 
@@ -517,7 +518,61 @@ module Vagrant
     #
     # @param [Pathname] path The path to the dotfile
     def upgrade_v1_dotfile(path)
-      raise "V1 environment detected. An auto-upgrade process will be made soon."
+      @logger.info("Upgrading V1 dotfile to V2 directory structure...")
+
+      # First, verify the file isn't empty. If it is an empty file, we
+      # just delete it and go on with life.
+      contents = path.read.strip
+      if contents.strip == ""
+        @logger.info("V1 dotfile was empty. Removing and moving on.")
+        path.delete
+        return
+      end
+
+      # Otherwise, verify there is valid JSON in here since a Vagrant
+      # environment would always ensure valid JSON. This is a sanity check
+      # to make sure we don't nuke a dotfile that is not ours...
+      @logger.debug("Attempting to parse JSON of V1 file")
+      json_data = nil
+      begin
+        json_data = JSON.parse(contents)
+        @logger.debug("JSON parsed successfully. Things are okay.")
+      rescue JSON::ParserError
+        # The file could've been tampered with since Vagrant 1.0.x is
+        # supposed to ensure that the contents are valid JSON. Show an error.
+        raise Errors::DotfileUpgradeJSONError,
+          :state_file => path.to_s
+      end
+
+      # Alright, let's upgrade this guy to the new structure. Start by
+      # backing up the old dotfile.
+      backup_file = path.dirname.join(".vagrant.v1.#{Time.now.to_i}")
+      @logger.info("Renaming old dotfile to: #{backup_file}")
+      path.rename(backup_file)
+
+      # Now, we create the actual local data directory. This should succeed
+      # this time since we renamed the old conflicting V1.
+      setup_local_data_path
+
+      if json_data["active"]
+        @logger.debug("Upgrading to V2 style for each active VM")
+        json_data["active"].each do |name, id|
+          @logger.info("Upgrading dotfile: #{name} (#{id})")
+
+          # Create the machine configuration directory
+          directory = @local_data_path.join("machines/#{name}/virtualbox")
+          FileUtils.mkdir_p(directory)
+
+          # Write the ID file
+          directory.join("id").open("w+") do |f|
+            f.write(id)
+          end
+        end
+      end
+
+      # Upgrade complete! Let the user know
+      @ui.info(I18n.t("vagrant.general.upgraded_v1_dotfile",
+                     :backup_path => backup_file.to_s))
     end
   end
 end

lib/vagrant/errors.rb

@@ -166,6 +166,10 @@ module Vagrant
       error_key(:dotfile_is_directory)
     end
 
+    class DotfileUpgradeJSONError < VagrantError
+      error_key(:dotfile_upgrade_json_error)
+    end
+
     class DownloaderFileDoesntExist < VagrantError
       status_code(37)
       error_key(:file_missing, "vagrant.downloaders.file")

templates/locales/en.yml

@@ -9,6 +9,17 @@ en:
 
         Old: %{old}
         New: %{new}
+      upgraded_v1_dotfile: |-
+        A Vagrant 1.0.x state file was found for this environment. Vagrant has
+        gone ahead and auto-upgraded this to the latest format. Everything
+        should continue working as normal. Beware, however, that older versions
+        of Vagrant may no longer be used with this environment.
+
+        However, in case anything went wrong, the old dotfile was backed up
+        to the location below. If everything is okay, it is safe to remove
+        this backup.
+
+        Backup: %{backup_path}
 
 #-------------------------------------------------------------------------------
 # Translations for exception classes
@@ -55,6 +66,24 @@ en:
         this command in another directory. If you aren't in a home directory,
         then please rename ".vagrant" to something else, or configure Vagrant
         to use another filename by modifying `config.vagrant.dotfile_name`.
+      dotfile_upgrade_json_error: |-
+        A Vagrant 1.0.x local state file was found. Vagrant is able to upgrade
+        this to the latest format automatically, however various checks are
+        put in place to verify data isn't incorrectly deleted. In this case,
+        the old state file was not valid JSON. Vagrant 1.0.x would store state
+        as valid JSON, meaning that this file was probably tampered with or
+        manually edited. Vagrant's auto-upgrade process cannot continue in this
+        case.
+
+        In most cases, this can be resolve by simply removing the state file.
+        Note however though that if Vagrant was previously managing virtual
+        machines, they may be left in an "orphan" state. That is, if they are
+        running or exist, they'll have to manually be removed.
+
+        If you're unsure what to do, ask the Vagrant mailing list or contact
+        support.
+
+        State file path: %{state_file}
       environment_locked: |-
         An instance of Vagrant is already running. Only one instance of Vagrant
         may run at any given time to avoid problems with VirtualBox inconsistencies

test/unit/vagrant/environment_test.rb

@@ -1,5 +1,7 @@
 require File.expand_path("../../base", __FILE__)
+require "json"
 require "pathname"
+require "tempfile"
 
 require "vagrant/util/file_mode"
 
@@ -91,6 +93,55 @@ describe Vagrant::Environment do
       instance = described_class.new(:local_data_path => dir)
       instance.local_data_path.to_s.should == dir
     end
+
+    describe "upgrading V1 dotfiles" do
+      let(:v1_dotfile_tempfile) { Tempfile.new("vagrant") }
+      let(:v1_dotfile)          { Pathname.new(v1_dotfile_tempfile.path) }
+      let(:local_data_path)     { v1_dotfile_tempfile.path }
+      let(:instance) { described_class.new(:local_data_path => local_data_path) }
+
+      it "should be fine if dotfile is empty" do
+        v1_dotfile.open("w+") do |f|
+          f.write("")
+        end
+
+        expect { instance }.to_not raise_error
+        Pathname.new(local_data_path).should be_directory
+      end
+
+      it "should upgrade all active VMs" do
+        active_vms = {
+          "foo" => "foo_id",
+          "bar" => "bar_id"
+        }
+
+        v1_dotfile.open("w+") do |f|
+          f.write(JSON.dump({
+            "active" => active_vms
+          }))
+        end
+
+        expect { instance }.to_not raise_error
+
+        local_data_pathname = Pathname.new(local_data_path)
+        foo_id_file = local_data_pathname.join("machines/foo/virtualbox/id")
+        foo_id_file.should be_file
+        foo_id_file.read.should == "foo_id"
+
+        bar_id_file = local_data_pathname.join("machines/bar/virtualbox/id")
+        bar_id_file.should be_file
+        bar_id_file.read.should == "bar_id"
+      end
+
+      it "should raise an error if invalid JSON" do
+        v1_dotfile.open("w+") do |f|
+          f.write("bad")
+        end
+
+        expect { instance }.
+          to raise_error(Vagrant::Errors::DotfileUpgradeJSONError)
+      end
+    end
   end
 
   describe "default provider" do
@@ -239,7 +290,7 @@ VF
 
     it "should return a machine object with the machine configuration" do
       # Create a provider
-      foo_config = Class.new do
+      foo_config = Class.new(Vagrant.plugin("2", :config)) do
         attr_accessor :value
       end