providers/virtualbox: allow and prefer static guest IPs for NFS

Since vbox guest properties are proving to be less reliable than we had
hoped, bring back the static config parsing mechanism for finding a
guest IP to hand to NFS. If we find a static IP (or set of IPs) we'll
use that instead of trying to probe guest properties.

This retains NFS support for DHCP interfaces while regaining the
reliability that we previously had when static IPs were required.

plugins/providers/virtualbox/action/prepare_nfs_settings.rb

@@ -34,8 +34,7 @@ module VagrantPlugins
         # The ! indicates that this method modifies its argument.
         def add_ips_to_env!(env)
           adapter, host_ip = find_host_only_adapter
-          machine_ip       = nil
-          machine_ip       = read_machine_ip(adapter) if adapter
+          machine_ip       = read_static_machine_ips || read_dynamic_machine_ip(adapter)
 
           raise Vagrant::Errors::NFSNoHostonlyNetwork if !host_ip || !machine_ip
 
@@ -61,6 +60,25 @@ module VagrantPlugins
           nil
         end
 
+        # Returns the IP address(es) of the guest by looking for static IPs
+        # given to host only adapters in the Vagrantfile
+        #
+        # @return [Array]<String> Configured static IPs
+        def read_static_machine_ips
+          ips = []
+          @machine.config.vm.networks.each do |type, options|
+            if type == :private_network && options[:ip].is_a?(String)
+              ips << options[:ip]
+            end
+          end
+
+          if ips.empty?
+            return nil
+          end
+
+          ips
+        end
+
         # Returns the IP address of the guest by looking at vbox guest property
         # for the appropriate guest adapter.
         #
@@ -69,7 +87,9 @@ module VagrantPlugins
         #
         # @param [Integer] adapter number to read IP for
         # @return [String] ip address of adapter
-        def read_machine_ip(adapter)
+        def read_dynamic_machine_ip(adapter)
+          return nil unless adapter
+
           # vbox guest properties are 0-indexed, while showvminfo network
           # interfaces are 1-indexed. go figure.
           guestproperty_adapter = adapter - 1

test/unit/plugins/providers/virtualbox/action/prepare_nfs_settings_test.rb

@@ -51,6 +51,10 @@ describe VagrantPlugins::ProviderVirtualBox::Action::PrepareNFSSettings do
         {name: "vmnet2", ip: "1.2.3.4"},
       ])
       driver.stub(:read_guest_ip).with(1).and_return("2.3.4.5")
+
+      # override sleep to 0 so test does not take seconds
+      retry_options = subject.retry_options
+      subject.stub(:retry_options).and_return(retry_options.merge(sleep: 0))
     end
 
     it "sets nfs_host_ip and nfs_machine_ip properly" do
@@ -74,10 +78,6 @@ describe VagrantPlugins::ProviderVirtualBox::Action::PrepareNFSSettings do
       ]
       driver.stub(:read_guest_ip) { raise_then_return.shift.call }
 
-      # override sleep to 0 so test does not take seconds
-      retry_options = subject.retry_options
-      subject.stub(:retry_options).and_return(retry_options.merge(sleep: 0))
-
       subject.call(env)
 
       env[:nfs_host_ip].should    == "1.2.3.4"
@@ -89,12 +89,21 @@ describe VagrantPlugins::ProviderVirtualBox::Action::PrepareNFSSettings do
         raise Vagrant::Errors::VirtualBoxGuestPropertyNotFound, :guest_property => 'stub'
       }
 
-      # override sleep to 0 so test does not take seconds
-      retry_options = subject.retry_options
-      subject.stub(:retry_options).and_return(retry_options.merge(sleep: 0))
-
       expect { subject.call(env) }.
         to raise_error(Vagrant::Errors::NFSNoGuestIP)
     end
+
+    it "allows statically configured guest IPs to work for NFS, even when guest property would fail" do
+      env[:machine].config.vm.network :private_network, ip: "11.12.13.14"
+
+      driver.stub(:read_guest_ip) {
+        raise Vagrant::Errors::VirtualBoxGuestPropertyNotFound, :guest_property => "stub"
+      }
+
+      subject.call(env)
+
+      env[:nfs_host_ip].should    == "1.2.3.4"
+      env[:nfs_machine_ip].should == ["11.12.13.14"]
+    end
   end
 end