Adding machine interface

This adds a machine interface that can be used to mock operations of
machine. This interface is subject to change as it reflects the Machine
structure.

Signed-off-by: xibz <[email protected]>

client_transports.go

@@ -1,3 +1,16 @@
+// Copyright 2018-2019 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License"). You may
+// not use this file except in compliance with the License. A copy of the
+// License is located at
+//
+//	http://aws.amazon.com/apache2.0/
+//
+// or in the "license" file accompanying this file. This file is distributed
+// on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
+// express or implied. See the License for the specific language governing
+// permissions and limitations under the License.
+
 package firecracker
 
 import (

client_transports_test.go

@@ -1,3 +1,16 @@
+// Copyright 2018-2019 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License"). You may
+// not use this file except in compliance with the License. A copy of the
+// License is located at
+//
+//	http://aws.amazon.com/apache2.0/
+//
+// or in the "license" file accompanying this file. This file is distributed
+// on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
+// express or implied. See the License for the specific language governing
+// permissions and limitations under the License.
+
 package firecracker
 
 import (

handlers.go

@@ -173,7 +173,13 @@ func NewSetMetadataHandler(metadata interface{}) Handler {
 	return Handler{
 		Name: SetMetadataHandlerName,
 		Fn: func(ctx context.Context, m *Machine) error {
-			return m.SetMetadata(ctx, metadata)
+			if _, err := m.client.PutMmds(ctx, metadata); err != nil {
+				m.logger.Errorf("Setting metadata: %s", err)
+				return err
+			}
+
+			m.logger.Printf("SetMetadata successful")
+			return nil
 		},
 	}
 }

machine.go

@@ -588,22 +588,12 @@ func (m *Machine) sendCtrlAltDel(ctx context.Context) error {
 	return err
 }
 
-// EnableMetadata will append or replace the metadata handler.
+// EnableMetadata will append or replace the metadata handler and only will be
+// called when calling the Machine Start operation.
 func (m *Machine) EnableMetadata(metadata interface{}) {
 	m.Handlers.FcInit = m.Handlers.FcInit.Swappend(NewSetMetadataHandler(metadata))
 }
 
-// SetMetadata sets the machine's metadata for MDDS
-func (m *Machine) SetMetadata(ctx context.Context, metadata interface{}) error {
-	if _, err := m.client.PutMmds(ctx, metadata); err != nil {
-		m.logger.Errorf("Setting metadata: %s", err)
-		return err
-	}
-
-	m.logger.Printf("SetMetadata successful")
-	return nil
-}
-
 // UpdateGuestDrive will modify the current guest drive of ID index with the new
 // parameters of the partialDrive.
 func (m *Machine) UpdateGuestDrive(ctx context.Context, driveID, pathOnHost string, opts ...PatchGuestDriveByIDOpt) error {

machine_test.go

@@ -637,7 +637,7 @@ func TestWaitForSocket(t *testing.T) {
 
 func testSetMetadata(ctx context.Context, t *testing.T, m *Machine) {
 	metadata := map[string]string{"key": "value"}
-	err := m.SetMetadata(ctx, metadata)
+	_, err := m.client.PutMmds(ctx, metadata)
 	if err != nil {
 		t.Errorf("failed to set metadata: %s", err)
 	}

machineiface.go

@@ -0,0 +1,29 @@
+// Copyright 2018-2019 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License"). You may
+// not use this file except in compliance with the License. A copy of the
+// License is located at
+//
+//	http://aws.amazon.com/apache2.0/
+//
+// or in the "license" file accompanying this file. This file is distributed
+// on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
+// express or implied. See the License for the specific language governing
+// permissions and limitations under the License.
+
+package firecracker
+
+import (
+	"context"
+)
+
+// MachineIface can be used for mocking and testing of the Machine. The Machine
+// is subject to change, meaning this interface would change.
+type MachineIface interface {
+	Start(context.Context) error
+	StopVMM() error
+	Shutdown(context.Context) error
+	Wait(context.Context) error
+	EnableMetadata(interface{})
+	UpdateGuestDrive(context.Context, string, string, ...PatchGuestDriveByIDOpt) error
+}

rate_limiter.go

@@ -1,3 +1,16 @@
+// Copyright 2018-2019 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License"). You may
+// not use this file except in compliance with the License. A copy of the
+// License is located at
+//
+//	http://aws.amazon.com/apache2.0/
+//
+// or in the "license" file accompanying this file. This file is distributed
+// on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
+// express or implied. See the License for the specific language governing
+// permissions and limitations under the License.
+
 package firecracker
 
 import (

rate_limiter_test.go

@@ -1,3 +1,16 @@
+// Copyright 2018-2019 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License"). You may
+// not use this file except in compliance with the License. A copy of the
+// License is located at
+//
+//	http://aws.amazon.com/apache2.0/
+//
+// or in the "license" file accompanying this file. This file is distributed
+// on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
+// express or implied. See the License for the specific language governing
+// permissions and limitations under the License.
+
 package firecracker_test
 
 import (