Support bidirectional requests over gateway

socket.go

@@ -19,10 +19,13 @@
 package main
 
 import (
+	"bytes"
 	"context"
 	"errors"
 	"io"
 	"net"
+	"net/http"
+	"net/url"
 	"os"
 	"path/filepath"
 	"strings"
@@ -31,6 +34,7 @@ import (
 	"github.com/google/uuid"
 	"github.com/rs/zerolog/log"
 	"github.com/smallnest/rpcx/server"
+	"github.com/smallnest/rpcx/share"
 	"github.com/vmihailenco/msgpack/v5"
 	"go.arsenm.dev/infinitime"
 	"go.arsenm.dev/infinitime/blefs"
@@ -46,7 +50,7 @@ var (
 	ErrDFUInvalidFile    = errors.New("provided file is invalid for given upgrade type")
 	ErrDFUNotEnoughFiles = errors.New("not enough files provided for given upgrade type")
 	ErrDFUInvalidUpgType = errors.New("invalid upgrade type")
-	ErrRPCXUsingGateway  = errors.New("bidirectional requests are unsupported over gateway")
+	ErrRPCXNoReturnURL   = errors.New("bidirectional requests over gateway require a returnURL field in the metadata")
 )
 
 type DoneMap map[string]chan struct{}
@@ -137,11 +141,11 @@ func (i *ITD) HeartRate(_ context.Context, _ none, out *uint8) error {
 }
 
 func (i *ITD) WatchHeartRate(ctx context.Context, _ none, out *string) error {
-	// Get client's connection
+	// Get client message sender
-	clientConn, ok := ctx.Value(server.RemoteConnContextKey).(net.Conn)
+	msgSender, ok := getMsgSender(ctx, i.srv)
 	// If user is using gateway, the client connection will not be available
 	if !ok {
-		return ErrRPCXUsingGateway
+		return ErrRPCXNoReturnURL
 	}
 
 	heartRateCh, cancel, err := i.dev.WatchHeartRate()
@@ -168,7 +172,7 @@ func (i *ITD) WatchHeartRate(ctx context.Context, _ none, out *string) error {
 				}
 
 				// Send response to connection if no done signal received
-				i.srv.SendMessage(clientConn, id, "HeartRateSample", nil, data)
+				msgSender.SendMessage(id, "HeartRateSample", nil, data)
 			}
 		}
 	}()
@@ -184,11 +188,11 @@ func (i *ITD) BatteryLevel(_ context.Context, _ none, out *uint8) error {
 }
 
 func (i *ITD) WatchBatteryLevel(ctx context.Context, _ none, out *string) error {
-	// Get client's connection
+	// Get client message sender
-	clientConn, ok := ctx.Value(server.RemoteConnContextKey).(net.Conn)
+	msgSender, ok := getMsgSender(ctx, i.srv)
 	// If user is using gateway, the client connection will not be available
 	if !ok {
-		return ErrRPCXUsingGateway
+		return ErrRPCXNoReturnURL
 	}
 
 	battLevelCh, cancel, err := i.dev.WatchBatteryLevel()
@@ -215,7 +219,7 @@ func (i *ITD) WatchBatteryLevel(ctx context.Context, _ none, out *string) error
 				}
 
 				// Send response to connection if no done signal received
-				i.srv.SendMessage(clientConn, id, "BatteryLevelSample", nil, data)
+				msgSender.SendMessage(id, "BatteryLevelSample", nil, data)
 			}
 		}
 	}()
@@ -231,11 +235,11 @@ func (i *ITD) Motion(_ context.Context, _ none, out *infinitime.MotionValues) er
 }
 
 func (i *ITD) WatchMotion(ctx context.Context, _ none, out *string) error {
-	// Get client's connection
+	// Get client message sender
-	clientConn, ok := ctx.Value(server.RemoteConnContextKey).(net.Conn)
+	msgSender, ok := getMsgSender(ctx, i.srv)
 	// If user is using gateway, the client connection will not be available
 	if !ok {
-		return ErrRPCXUsingGateway
+		return ErrRPCXNoReturnURL
 	}
 
 	motionValsCh, cancel, err := i.dev.WatchMotion()
@@ -262,7 +266,7 @@ func (i *ITD) WatchMotion(ctx context.Context, _ none, out *string) error {
 				}
 
 				// Send response to connection if no done signal received
-				i.srv.SendMessage(clientConn, id, "MotionSample", nil, data)
+				msgSender.SendMessage(id, "MotionSample", nil, data)
 			}
 		}
 	}()
@@ -278,11 +282,11 @@ func (i *ITD) StepCount(_ context.Context, _ none, out *uint32) error {
 }
 
 func (i *ITD) WatchStepCount(ctx context.Context, _ none, out *string) error {
-	// Get client's connection
+	// Get client message sender
-	clientConn, ok := ctx.Value(server.RemoteConnContextKey).(net.Conn)
+	msgSender, ok := getMsgSender(ctx, i.srv)
 	// If user is using gateway, the client connection will not be available
 	if !ok {
-		return ErrRPCXUsingGateway
+		return ErrRPCXNoReturnURL
 	}
 
 	stepCountCh, cancel, err := i.dev.WatchStepCount()
@@ -309,7 +313,7 @@ func (i *ITD) WatchStepCount(ctx context.Context, _ none, out *string) error {
 				}
 
 				// Send response to connection if no done signal received
-				i.srv.SendMessage(clientConn, id, "StepCountSample", nil, data)
+				msgSender.SendMessage(id, "StepCountSample", nil, data)
 			}
 		}
 	}()
@@ -386,8 +390,8 @@ func (i *ITD) FirmwareUpgrade(ctx context.Context, reqData api.FwUpgradeData, ou
 	id := uuid.New().String()
 	*out = id
 
-	// Get client's connection
+	// Get client message sender
-	clientConn, ok := ctx.Value(server.RemoteConnContextKey).(net.Conn)
+	msgSender, ok := getMsgSender(ctx, i.srv)
 	// If user is using gateway, the client connection will not be available
 	if ok {
 		go func() {
@@ -399,11 +403,11 @@ func (i *ITD) FirmwareUpgrade(ctx context.Context, reqData api.FwUpgradeData, ou
 					continue
 				}
 
-				i.srv.SendMessage(clientConn, id, "DFUProgress", nil, data)
+				msgSender.SendMessage(id, "DFUProgress", nil, data)
 			}
 
 			firmwareUpdating = false
-			i.srv.SendMessage(clientConn, id, "Done", nil, nil)
+			msgSender.SendMessage(id, "Done", nil, nil)
 		}()
 	}
 
@@ -506,8 +510,8 @@ func (fs *FS) Upload(ctx context.Context, paths [2]string, out *string) error {
 	id := uuid.New().String()
 	*out = id
 
-	// Get client's connection
+	// Get client message sender
-	clientConn, ok := ctx.Value(server.RemoteConnContextKey).(net.Conn)
+	msgSender, ok := getMsgSender(ctx, fs.srv)
 	// If user is using gateway, the client connection will not be available
 	if ok {
 		go func() {
@@ -522,10 +526,10 @@ func (fs *FS) Upload(ctx context.Context, paths [2]string, out *string) error {
 					continue
 				}
 
-				fs.srv.SendMessage(clientConn, id, "FSProgress", nil, data)
+				msgSender.SendMessage(id, "FSProgress", nil, data)
 			}
 
-			fs.srv.SendMessage(clientConn, id, "Done", nil, nil)
+			msgSender.SendMessage(id, "Done", nil, nil)
 		}()
 	}
 
@@ -554,8 +558,8 @@ func (fs *FS) Download(ctx context.Context, paths [2]string, out *string) error
 	id := uuid.New().String()
 	*out = id
 
-	// Get client's connection
+	// Get client message sender
-	clientConn, ok := ctx.Value(server.RemoteConnContextKey).(net.Conn)
+	msgSender, ok := getMsgSender(ctx, fs.srv)
 	// If user is using gateway, the client connection will not be available
 	if ok {
 		go func() {
@@ -570,10 +574,10 @@ func (fs *FS) Download(ctx context.Context, paths [2]string, out *string) error
 					continue
 				}
 
-				fs.srv.SendMessage(clientConn, id, "FSProgress", nil, data)
+				msgSender.SendMessage(id, "FSProgress", nil, data)
 			}
 
-			fs.srv.SendMessage(clientConn, id, "Done", nil, nil)
+			msgSender.SendMessage(id, "Done", nil, nil)
 			localFile.Close()
 			remoteFile.Close()
 		}()
@@ -608,3 +612,66 @@ func cleanPaths(paths []string) []string {
 	}
 	return paths
 }
+
+func getMsgSender(ctx context.Context, srv *server.Server) (MessageSender, bool) {
+	// Get client message sender
+	clientConn, ok := ctx.Value(server.RemoteConnContextKey).(net.Conn)
+	// If the connection exists, use rpcMsgSender
+	if ok {
+		return &rpcMsgSender{srv, clientConn}, true
+	} else {
+		// Get metadata if it exists
+		metadata, ok := ctx.Value(share.ReqMetaDataKey).(map[string]string)
+		if !ok {
+			return nil, false
+		}
+		// Get returnURL field from metadata if it exists
+		returnURL, ok := metadata["returnURL"]
+		if !ok {
+			return nil, false
+		}
+		// Use httpMsgSender
+		return &httpMsgSender{returnURL}, true
+	}
+
+}
+
+type MessageSender interface {
+	SendMessage(servicePath, serviceMethod string, metadata map[string]string, data []byte) error
+}
+
+type rpcMsgSender struct {
+	srv  *server.Server
+	conn net.Conn
+}
+
+func (r *rpcMsgSender) SendMessage(servicePath, serviceMethod string, metadata map[string]string, data []byte) error {
+
+	return r.srv.SendMessage(r.conn, servicePath, serviceMethod, metadata, data)
+}
+
+type httpMsgSender struct {
+	url string
+}
+
+func (h *httpMsgSender) SendMessage(servicePath, serviceMethod string, metadata map[string]string, data []byte) error {
+	req, err := http.NewRequest(http.MethodPost, h.url, bytes.NewReader(data))
+	if err != nil {
+		return err
+	}
+
+	req.Header.Set("X-RPCX-ServicePath", servicePath)
+	req.Header.Set("X-RPCX-ServiceMethod", serviceMethod)
+
+	query := url.Values{}
+	for k, v := range metadata {
+		query.Set(k, v)
+	}
+	req.Header.Set("X-RPCX-Meta", query.Encode())
+
+	res, err := http.DefaultClient.Do(req)
+	if err != nil {
+		return err
+	}
+	return res.Body.Close()
+}