Vagrantfile: add a configuration patch to fix slow networking on some…

… hosts.

See also hashicorp/vagrant#1172 and https://gist.github.com/simono/73e37d8c3a45664c7045 for a description of the problem and the origins of this fix.

Signed-off-by: Eric Myhre <eric@flynn.io>

Vagrantfile

@@ -25,6 +25,12 @@ Vagrant.configure(VAGRANTFILE_API_VERSION) do |config|
     v.cpus = ENV["VAGRANT_CPUS"] || 2
   end
 
+  # Address issues some hosts experience with networking (specifically, DNS latency) inside the development environment VM.
+  # See also mitchellh/vagrant#1172 for a description of the problem.
+  config.vm.provision :shell, inline: <<SCRIPT
+    if [ ! $(grep single-request-reopen /etc/resolvconf/resolv.conf.d/base) ]; then echo "options single-request-reopen" >> /etc/resolvconf/resolv.conf.d/base && resolvconf -u; fi
+SCRIPT
+
   config.vm.provision "shell", privileged: false, inline: <<SCRIPT
     grep '^export GOPATH' ~/.bashrc || echo export GOPATH=~/go >> ~/.bashrc
     grep '^export PATH' ~/.bashrc || echo export PATH=\\\$PATH:~/go/bin:/vagrant/script >> ~/.bashrc