Detect guest for machine

internal/core/machine.go

@@ -1,12 +1,14 @@
 package core
 
 import (
+	"fmt"
 	"reflect"
 
 	"github.com/golang/protobuf/ptypes"
 	"github.com/mitchellh/mapstructure"
 
 	"github.com/hashicorp/go-hclog"
+	"github.com/hashicorp/vagrant-plugin-sdk/component"
 	"github.com/hashicorp/vagrant-plugin-sdk/core"
 	"github.com/hashicorp/vagrant-plugin-sdk/proto/vagrant_plugin_sdk"
 	"github.com/hashicorp/vagrant/internal/server/proto/vagrant_server"
@@ -41,8 +43,67 @@ func (m *Machine) Box() (b *core.Box, err error) {
 
 // Guest implements core.Machine
 func (m *Machine) Guest() (g core.Guest, err error) {
-	// TODO: need Vagrantfile + communicator
-	return
+	guests, err := m.project.basis.typeComponents(m.ctx, component.GuestType)
+	if err != nil {
+		return
+	}
+
+	var result core.Guest
+	var result_name string
+
+	for name, g := range guests {
+		guest := g.Value.(core.Guest)
+		detected, err := guest.Detect(m.toTarget())
+		if err != nil {
+			m.logger.Error("guest error on detection check",
+				"plugin", name,
+				"type", "Guest",
+				"error", err)
+
+			continue
+		}
+		if result == nil {
+			if detected {
+				result = guest
+				result_name = name
+			}
+			continue
+		}
+
+		gp, err := guest.Parents()
+		if err != nil {
+			m.logger.Error("failed to get parents from guest",
+				"plugin", name,
+				"type", "Guest",
+				"error", err)
+
+			continue
+		}
+
+		rp, err := result.Parents()
+		if err != nil {
+			m.logger.Error("failed to get parents from guest",
+				"plugin", result_name,
+				"type", "Guest",
+				"error", err)
+
+			continue
+		}
+
+		if len(gp) > len(rp) {
+			result = guest
+			result_name = name
+		}
+	}
+
+	if result == nil {
+		return nil, fmt.Errorf("failed to detect guest plugin for current platform")
+	}
+
+	m.logger.Info("guest detection complete",
+		"name", result_name)
+
+	return result, nil
 }
 
 func (m *Machine) Inspect() (printable string, err error) {
@@ -97,5 +158,9 @@ func (m *Machine) SaveMachine() (err error) {
 	return m.Save()
 }
 
+func (m *Machine) toTarget() core.Target {
+	return m
+}
+
 var _ core.Machine = (*Machine)(nil)
 var _ core.Target = (*Machine)(nil)