refactor: move validation/defaults to app (#514)

This change moves the adding of the mmds network interface and
validation of the microvm spec to the app and out of the gRPC
infrastructure.

Signed-off-by: Richard Case <richard.case@outlook.com>

Author: richardcase

core/application/app_test.go

@@ -629,12 +629,13 @@ func createTestSpecWithMetadata(name, ns, uid string, metadata map[string]string
 				{
 					AllowMetadataRequests: true,
 					GuestMAC:              "AA:FF:00:00:00:01",
-					GuestDeviceName:       "eth0",
+					GuestDeviceName:       "mmds",
+					Type:                  models.IfaceTypeTap,
 				},
 				{
 					AllowMetadataRequests: false,
 					GuestDeviceName:       "eth1",
-					// TODO:
+					Type:                  models.IfaceTypeMacvtap,
 				},
 			},
 			RootVolume: models.Volume{

core/application/commands.go

@@ -14,17 +14,28 @@ import (
 	"github.com/weaveworks-liquidmetal/flintlock/core/ports"
 	"github.com/weaveworks-liquidmetal/flintlock/pkg/defaults"
 	"github.com/weaveworks-liquidmetal/flintlock/pkg/log"
+	"github.com/weaveworks-liquidmetal/flintlock/pkg/validation"
 	"sigs.k8s.io/yaml"
 )
 
+const (
+	MetadataInterfaceName = "mmds"
+)
+
 func (a *app) CreateMicroVM(ctx context.Context, mvm *models.MicroVM) (*models.MicroVM, error) {
 	logger := log.GetLogger(ctx).WithField("component", "app")
-	logger.Trace("creating microvm")
+	logger.Debug("creating microvm")
 
 	if mvm == nil {
 		return nil, coreerrs.ErrSpecRequired
 	}
 
+	logger.Trace("validating model")
+	validator := validation.NewValidator()
+	if validErr := validator.ValidateStruct(mvm); validErr != nil {
+		return nil, fmt.Errorf("an error occurred when attempting to validate microvm spec: %w", validErr)
+	}
+
 	if mvm.ID.IsEmpty() {
 		name, err := a.ports.IdentifierService.GenerateRandom()
 		if err != nil {
@@ -70,6 +81,7 @@ func (a *app) CreateMicroVM(ctx context.Context, mvm *models.MicroVM) (*models.M
 	if err != nil {
 		return nil, fmt.Errorf("adding instance data: %w", err)
 	}
+	a.addMetadataInterface(mvm)
 
 	// Set the timestamp when the VMspec was created.
 	mvm.Spec.CreatedAt = a.ports.Clock().Unix()
@@ -171,3 +183,24 @@ func (a *app) addInstanceData(vm *models.MicroVM, logger *logrus.Entry) error {
 
 	return nil
 }
+
+func (a *app) addMetadataInterface(mvm *models.MicroVM) {
+	for i := range mvm.Spec.NetworkInterfaces {
+		netInt := mvm.Spec.NetworkInterfaces[i]
+		if netInt.GuestDeviceName == MetadataInterfaceName {
+			return
+		}
+	}
+
+	mvm.Spec.NetworkInterfaces = append(mvm.Spec.NetworkInterfaces, models.NetworkInterface{
+		GuestDeviceName:       MetadataInterfaceName,
+		Type:                  models.IfaceTypeTap,
+		AllowMetadataRequests: true,
+		GuestMAC:              "AA:FF:00:00:00:01",
+		StaticAddress: &models.StaticAddress{
+			Address: "169.254.0.1/16",
+		},
+	})
+
+	return
+}

infrastructure/grpc/convert.go

@@ -72,10 +72,6 @@ func convertMicroVMToModel(spec *types.MicroVMSpec) (*models.MicroVM, error) {
 		convertedModel.Spec.NetworkInterfaces = append(convertedModel.Spec.NetworkInterfaces, *convertedNetInt)
 	}
 
-	ifaces := []models.NetworkInterface{*newMetadataInterface()}
-	ifaces = append(ifaces, convertedModel.Spec.NetworkInterfaces...)
-	convertedModel.Spec.NetworkInterfaces = ifaces
-
 	convertedModel.Spec.Metadata = map[string]string{}
 	for metadataKey, metadataValue := range spec.Metadata {
 		convertedModel.Spec.Metadata[metadataKey] = metadataValue

infrastructure/grpc/defaults.go

@@ -2,16 +2,13 @@ package grpc
 
 import (
 	"context"
-	"errors"
 	"fmt"
 
-	"github.com/go-playground/validator/v10"
 	mvmv1 "github.com/weaveworks-liquidmetal/flintlock/api/services/microvm/v1alpha1"
 	"github.com/weaveworks-liquidmetal/flintlock/api/types"
 	"github.com/weaveworks-liquidmetal/flintlock/core/models"
 	"github.com/weaveworks-liquidmetal/flintlock/core/ports"
 	"github.com/weaveworks-liquidmetal/flintlock/pkg/log"
-	"github.com/weaveworks-liquidmetal/flintlock/pkg/validation"
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/status"
 	"google.golang.org/protobuf/types/known/emptypb"
@@ -22,14 +19,12 @@ func NewServer(commandUC ports.MicroVMCommandUseCases, queryUC ports.MicroVMQuer
 	return &server{
 		commandUC: commandUC,
 		queryUC:   queryUC,
-		validator: validation.NewValidator(),
 	}
 }
 
 type server struct {
 	commandUC ports.MicroVMCommandUseCases
 	queryUC   ports.MicroVMQueryUseCases
-	validator validation.Validator
 }
 
 func (s *server) CreateMicroVM(
@@ -51,22 +46,6 @@ func (s *server) CreateMicroVM(
 		return nil, fmt.Errorf("converting request: %w", err)
 	}
 
-	logger.Trace("validating model")
-
-	var valErrors validator.ValidationErrors
-
-	if err = s.validator.ValidateStruct(modelSpec); err != nil {
-		if errors.As(err, &valErrors) {
-			return nil, status.Errorf(
-				codes.InvalidArgument,
-				"an error occurred when attempting to validate the request: %v",
-				err,
-			)
-		}
-
-		return nil, status.Errorf(codes.Internal, "an error occurred: %v", err)
-	}
-
 	logger.Infof("creating microvm %s", modelSpec.ID)
 
 	createdModel, err := s.commandUC.CreateMicroVM(ctx, modelSpec)