Automate required plugin installation.

vagrant/.vagrantplugins.rb

+# -*- mode: ruby -*-
+# vi: set ft=ruby :
+
+def install_plugins(plugins)
+  not_installed = []
+  plugins.each do |plugin|
+    unless Vagrant.has_plugin?(plugin)
+      not_installed << plugin
+    end
+  end
+
+  if not_installed.any?
+    puts "The following required plugins must be installed:"
+    puts "'#{not_installed.join("', '")}'"
+    print "Install? [y]/n: "
+    unless STDIN.gets.chomp == "n"
+      not_installed.each { |plugin| install_plugin(plugin) }
+    else
+      exit
+    end
+    $? ? continue : raise('Plugin installation failed, see errors above.')
+  end
+end
+
+def install_plugin(plugin)
+  system "vagrant plugin install #{plugin}"
+end
+
+# If plugins successfully installed, restart vagrant to detect changes.
+def continue
+  exec "vagrant #{ARGV[0]}"
+end
+

vagrant/base/analyticstack/Vagrantfile

 Vagrant.require_version ">= 1.8.7"
-unless Vagrant.has_plugin?("vagrant-vbguest")
-  raise "Please install the vagrant-vbguest plugin by running `vagrant plugin install vagrant-vbguest`"
-end
+require_relative '.vagrantplugins'
+install_plugins(['vagrant-vbguest'])
 
 VAGRANTFILE_API_VERSION = "2"
 

vagrant/base/cluster/Vagrantfile

 # -*- mode: ruby -*-
-
 # vi: set ft=ruby :
 
 VAGRANTFILE_API_VERSION = "2"

vagrant/base/devstack/Vagrantfile

 Vagrant.require_version ">= 1.8.7"
-unless Vagrant.has_plugin?("vagrant-vbguest")
-  raise "Please install the vagrant-vbguest plugin by running `vagrant plugin install vagrant-vbguest`"
-end
+require_relative '.vagrantplugins'
+install_plugins(['vagrant-vbguest'])
 
 VAGRANTFILE_API_VERSION = "2"
 

vagrant/release/analyticstack/Vagrantfile

 Vagrant.require_version ">= 1.8.7"
-unless Vagrant.has_plugin?("vagrant-vbguest")
-  raise "Please install the vagrant-vbguest plugin by running `vagrant plugin install vagrant-vbguest`"
-end
+require_relative '.vagrantplugins'
+install_plugins(['vagrant-vbguest'])
 
 VAGRANTFILE_API_VERSION = "2"
 

vagrant/release/devstack/Vagrantfile

 Vagrant.require_version ">= 1.8.7"
-unless Vagrant.has_plugin?("vagrant-vbguest")
-  raise "Please install the vagrant-vbguest plugin by running `vagrant plugin install vagrant-vbguest`"
-end
+require_relative '.vagrantplugins'
+install_plugins(['vagrant-vbguest'])
 
 VAGRANTFILE_API_VERSION = "2"