providers/docker: only correct port collisions if not host VM

plugins/providers/docker/action.rb

@@ -16,7 +16,6 @@ module VagrantPlugins
             # If the VM is NOT created yet, then do the setup steps
             if env[:result]
               b2.use EnvSet, :port_collision_repair => true
-              b2.use HandleForwardedPortCollisions
 
               b2.use Call, HasSSH do |env2, b3|
                 if env2[:result]
@@ -28,6 +27,14 @@ module VagrantPlugins
                 end
               end
 
+              b2.use Call, HostMachineRequired do |env2, b3|
+                if !env[:result]
+                  # We're not using a proxy host VM, so just handle
+                  # port collisions like we would any other system.
+                  b3.use HandleForwardedPortCollisions
+                end
+              end
+
               b2.use PrepareNFSValidIds
               b2.use SyncedFolderCleanup
               b2.use SyncedFolders
@@ -220,6 +227,7 @@ module VagrantPlugins
       autoload :ForwardPorts, action_root.join("forward_ports")
       autoload :HasSSH, action_root.join("has_ssh")
       autoload :HostMachine, action_root.join("host_machine")
+      autoload :HostMachineRequired, action_root.join("host_machine_required")
       autoload :HostMachineSyncFolders, action_root.join("host_machine_sync_folders")
       autoload :HostMachineSyncFoldersDisable, action_root.join("host_machine_sync_folders_disable")
       autoload :PrepareSSH, action_root.join("prepare_ssh")

plugins/providers/docker/action/host_machine_required.rb

@@ -0,0 +1,17 @@
+module VagrantPlugins
+  module DockerProvider
+    module Action
+      # This middleware is used with Call to test if we're using a host VM.
+      class HostMachineRequired
+        def initialize(app, env)
+          @app = app
+        end
+
+        def call(env)
+          env[:result] = env[:machine].provider.host_vm?
+          @app.call(env)
+        end
+      end
+    end
+  end
+end