guests/coreos: proper guest IP detection [GH-2146]

CHANGELOG.md

@@ -11,6 +11,7 @@ BUG FIXES:
   - core: Handle the case where we get an EACCES cleaning up the .vagrant
     directory.
   - core: Fix exception on upgrade warnings from V1 to V2. [GH-2142]
+  - guests/coreos: Proper IP detection. [GH-2146]
   - hosts/linux: NFS exporting works properly again. [GH-2137]
   - provisioners/chef: Work even with restrictive umask on user. [GH-2121]
   - provisioners/chef: Fix environment validation to be less restrictive.

plugins/guests/coreos/cap/configure_networks.rb

@@ -28,9 +28,16 @@ module VagrantPlugins
             primary_machine_config = machine.env.active_machines.first
             primary_machine = machine.env.machine(*primary_machine_config, true)
 
-            get_ip = ->(machine) do
+            get_ip = lambda do |machine|
-              _, network_config = machine.config.vm.networks.detect { |type, _| type == :private_network}
+              ip = nil
-              network_config[:ip]
+              machine.config.vm.networks.each do |type, opts|
+                if type == :private_network && opts[:ip]
+                  ip = opts[:ip]
+                  break
+                end
+              end
+
+              ip
             end
 
             primary_machine_ip = get_ip.(primary_machine)