add experimental plugin system

sdk/plugin/notifier/grpc.go

@@ -0,0 +1,72 @@
+package notifier
+
+import (
+	"context"
+	"time"
+
+	"google.golang.org/protobuf/types/known/emptypb"
+	"google.golang.org/protobuf/types/known/timestamppb"
+
+	"github.com/drakkan/sftpgo/v2/sdk/plugin/notifier/proto"
+)
+
+const (
+	rpcTimeout = 20 * time.Second
+)
+
+// GRPCClient is an implementation of Notifier interface that talks over RPC.
+type GRPCClient struct {
+	client proto.NotifierClient
+}
+
+// NotifyFsEvent implements the Notifier interface
+func (c *GRPCClient) NotifyFsEvent(action, username, fsPath, fsTargetPath, sshCmd, protocol string, fileSize int64, status int) error {
+	ctx, cancel := context.WithTimeout(context.Background(), rpcTimeout)
+	defer cancel()
+
+	_, err := c.client.SendFsEvent(ctx, &proto.FsEvent{
+		Timestamp:    timestamppb.New(time.Now()),
+		Action:       action,
+		Username:     username,
+		FsPath:       fsPath,
+		FsTargetPath: fsTargetPath,
+		SshCmd:       sshCmd,
+		FileSize:     fileSize,
+		Protocol:     protocol,
+		Status:       int32(status),
+	})
+
+	return err
+}
+
+// NotifyUserEvent implements the Notifier interface
+func (c *GRPCClient) NotifyUserEvent(action string, user []byte) error {
+	ctx, cancel := context.WithTimeout(context.Background(), rpcTimeout)
+	defer cancel()
+
+	_, err := c.client.SendUserEvent(ctx, &proto.UserEvent{
+		Timestamp: timestamppb.New(time.Now()),
+		Action:    action,
+		User:      user,
+	})
+
+	return err
+}
+
+// GRPCServer defines the gRPC server that GRPCClient talks to.
+type GRPCServer struct {
+	Impl Notifier
+}
+
+// SendFsEvent implements the serve side fs notify method
+func (s *GRPCServer) SendFsEvent(ctx context.Context, req *proto.FsEvent) (*emptypb.Empty, error) {
+	err := s.Impl.NotifyFsEvent(req.Action, req.Username, req.FsPath, req.FsTargetPath, req.SshCmd,
+		req.Protocol, req.FileSize, int(req.Status))
+	return &emptypb.Empty{}, err
+}
+
+// SendUserEvent implements the serve side user notify method
+func (s *GRPCServer) SendUserEvent(ctx context.Context, req *proto.UserEvent) (*emptypb.Empty, error) {
+	err := s.Impl.NotifyUserEvent(req.Action, req.User)
+	return &emptypb.Empty{}, err
+}