Install latest Go toolchain on vagrant dev vms

Vagrantfile

@@ -1,7 +1,7 @@
 VAGRANTFILE_API_VERSION = "2"
 
 vm_ip = "172.16.0.3" # arbitrary private IP
-pkgs = "lxc-docker golang ethtool libpcap-dev git mercurial"
+pkgs = "lxc-docker build-essential ethtool libpcap-dev git mercurial"
 
 Vagrant.configure(VAGRANTFILE_API_VERSION) do |config|
   config.vm.box = "phusion/ubuntu-14.04-amd64"
@@ -14,14 +14,19 @@ Vagrant.configure(VAGRANTFILE_API_VERSION) do |config|
   config.vm.provision :shell, :inline => "sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys 36A1D7869245C8950F966E92D8576A8BA88D21E9"
   config.vm.provision :shell, :inline => "echo deb https://get.docker.io/ubuntu docker main > /etc/apt/sources.list.d/docker.list"
 
-  pkg_cmd = "apt-get update -qq; " \
-  "apt-get install -q -y --force-yes --no-install-recommends "
-  pkg_cmd << pkgs
+  pkg_cmd = "export DEBIAN_FRONTEND=noninteractive; " \
+    "apt-get update -qq; " \
+    "apt-get install -qq --no-install-recommends #{pkgs}"
+
+  install_go_toolchain = "curl -s https://storage.googleapis.com/golang/go1.4.linux-amd64.tar.gz | tar xz -C /usr/local"
+
   config.vm.provision :shell, :inline => pkg_cmd
+  config.vm.provision :shell, :inline => install_go_toolchain
   config.vm.provision :shell, :inline => "usermod -a -G docker vagrant; "
   config.vm.provision :shell, :inline => "echo export GOPATH=/home/vagrant >> /home/vagrant/.bashrc"
+  config.vm.provision :shell, :inline => "echo export PATH=/usr/local/go/bin:${PATH} >> /home/vagrant/.bashrc"
   config.vm.provision :shell, :inline => "chown -R vagrant:vagrant /home/vagrant/src"
-  config.vm.provision :shell, :inline => "sudo go install -a -tags netgo std"
+  config.vm.provision :shell, :inline => "/usr/local/go/bin/go clean -i net; /usr/local/go/bin/go install -tags netgo std"
 
 end