Added support for creating and loading snapshots of VM.

Notes:
1. Uses logging-only branch from ustiugov/firecracker-go-sdk
2. Firecracker logs path is hard-coded.

Signed-off-by: Plamen Petrov <[email protected]>

Author: plamenmpetrov

firecracker-control/local.go

@@ -632,3 +632,60 @@ func (s *local) ResumeVM(ctx context.Context, req *proto.ResumeVMRequest) (*empt
 
 	return resp, nil
 }
+
+// CreateSnapshot Creates a snapshot of a VM
+func (s *local) CreateSnapshot(ctx context.Context, req *proto.CreateSnapshotRequest) (*empty.Empty, error) {
+	client, err := s.shimFirecrackerClient(ctx, req.VMID)
+	if err != nil {
+		return nil, err
+	}
+
+	defer client.Close()
+
+	resp, err := client.CreateSnapshot(ctx, req)
+	if err != nil {
+		s.logger.WithError(err).Error()
+		return nil, err
+	}
+
+	return resp, nil
+}
+
+// LoadSnapshot Loads a snapshot of a VM
+func (s *local) LoadSnapshot(ctx context.Context, req *proto.LoadSnapshotRequest) (*empty.Empty, error) {
+	client, err := s.shimFirecrackerClient(ctx, req.VMID)
+	if err != nil {
+		return nil, err
+	}
+
+	defer client.Close()
+
+	resp, err := client.LoadSnapshot(ctx, req)
+	if err != nil {
+		s.logger.WithError(err).Error()
+		return nil, err
+	}
+
+	return resp, nil
+}
+
+// Offload Shuts down a VM started through the firecracker go sdk and deletes
+// the corresponding firecracker socket. All of the other resources (shim, other sockets)
+// will persist.
+func (s *local) Offload(ctx context.Context, req *proto.OffloadRequest) (*empty.Empty, error) {
+	client, err := s.shimFirecrackerClient(ctx, req.VMID)
+	if err != nil {
+		return nil, err
+	}
+
+	defer client.Close()
+
+	resp, err := client.Offload(ctx, req)
+	if err != nil {
+		s.logger.WithError(err).Error()
+		return nil, err
+	}
+
+	return resp, nil
+}
+

firecracker-control/service.go

@@ -126,3 +126,18 @@ func (s *service) UpdateBalloonStats(ctx context.Context, req *proto.UpdateBallo
 	log.G(ctx).Debug("Updating balloon device statistics polling interval")
 	return s.local.UpdateBalloonStats(ctx, req)
 }
+
+func (s *service) LoadSnapshot(ctx context.Context, req *proto.LoadSnapshotRequest) (*empty.Empty, error) {
+	log.G(ctx).Debugf("load snapshot request: %+v", req)
+	return s.local.LoadSnapshot(ctx, req)
+}
+
+func (s *service) CreateSnapshot(ctx context.Context, req *proto.CreateSnapshotRequest) (*empty.Empty, error) {
+	log.G(ctx).Debugf("create snapshot request: %+v", req)
+	return s.local.CreateSnapshot(ctx, req)
+}
+
+func (s *service) Offload(ctx context.Context, req *proto.OffloadRequest) (*empty.Empty, error) {
+	log.G(ctx).Debugf("offload request: %+v", req)
+	return s.local.Offload(ctx, req)
+}

proto/firecracker.pb.go

@@ -103,6 +103,23 @@ enum DriveExposePolicy {
     BIND = 1;
 }
 
+message CreateSnapshotRequest {
+    string VMID = 1;
+    string SnapshotFilePath = 2;
+    string MemFilePath = 3;
+}
+
+message LoadSnapshotRequest {
+    string VMID = 1;
+    string SnapshotFilePath = 2;
+    string MemFilePath = 3;
+}
+
+message OffloadRequest {
+    string VMID = 1;
+}
+
+
 message JailerConfig {
     string NetNS = 1;
     // List of the physical numbers of the CPUs on which processes in that