Add gRPC interface for board list watcher (#1048)

cli/board/list.go

@@ -25,7 +25,6 @@ import (
 	"github.com/arduino/arduino-cli/cli/errorcodes"
 	"github.com/arduino/arduino-cli/cli/feedback"
 	"github.com/arduino/arduino-cli/cli/instance"
-	"github.com/arduino/arduino-cli/commands"
 	"github.com/arduino/arduino-cli/commands/board"
 	rpc "github.com/arduino/arduino-cli/rpc/commands"
 	"github.com/arduino/arduino-cli/table"
@@ -90,8 +89,7 @@ func runListCommand(cmd *cobra.Command, args []string) {
 }
 
 func watchList(cmd *cobra.Command, inst *rpc.Instance) {
-	pm := commands.GetPackageManager(inst.Id)
-	eventsChan, err := commands.WatchListBoards(pm)
+	eventsChan, err := board.Watch(inst.Id, nil)
 	if err != nil {
 		feedback.Errorf("Error detecting boards: %v", err)
 		os.Exit(errorcodes.ErrNetwork)
@@ -105,28 +103,13 @@ func watchList(cmd *cobra.Command, inst *rpc.Instance) {
 	}
 
 	for event := range eventsChan {
-		boards := []*rpc.BoardListItem{}
-		if event.Type == "add" {
-			boards, err = board.Identify(pm, &commands.BoardPort{
-				Address:             event.Port.Address,
-				Label:               event.Port.AddressLabel,
-				Prefs:               event.Port.Properties,
-				IdentificationPrefs: event.Port.IdentificationProperties,
-				Protocol:            event.Port.Protocol,
-				ProtocolLabel:       event.Port.ProtocolLabel,
-			})
-			if err != nil {
-				feedback.Errorf("Error identifying board: %v", err)
-				os.Exit(errorcodes.ErrNetwork)
-			}
-		}
-
 		feedback.PrintResult(watchEvent{
-			Type:          event.Type,
+			Type:          event.EventType,
 			Address:       event.Port.Address,
 			Protocol:      event.Port.Protocol,
 			ProtocolLabel: event.Port.ProtocolLabel,
-			Boards:        boards,
+			Boards:        event.Port.Boards,
+			Error:         event.Error,
 		})
 	}
 }
@@ -198,6 +181,7 @@ type watchEvent struct {
 	Protocol      string               `json:"protocol,omitempty"`
 	ProtocolLabel string               `json:"protocol_label,omitempty"`
 	Boards        []*rpc.BoardListItem `json:"boards,omitempty"`
+	Error         string               `json:"error,omitempty"`
 }
 
 func (dr watchEvent) Data() interface{} {

client_example/main.go

@@ -26,6 +26,7 @@ import (
 	"path"
 	"path/filepath"
 	"strings"
+	"time"
 
 	rpc "github.com/arduino/arduino-cli/rpc/commands"
 	dbg "github.com/arduino/arduino-cli/rpc/debug"
@@ -154,6 +155,10 @@ func main() {
 	log.Println("calling BoardList()")
 	callBoardList(client, instance)
 
+	// Watch for boards connection and disconnection
+	log.Println("calling BoardListWatch()")
+	callBoardListWatch(client, instance)
+
 	// Uninstall a platform
 	log.Println("calling PlatformUninstall(arduino:samd)")
 	callPlatformUnInstall(client, instance)
@@ -592,6 +597,41 @@ func callBoardList(client rpc.ArduinoCoreClient, instance *rpc.Instance) {
 	}
 }
 
+func callBoardListWatch(client rpc.ArduinoCoreClient, instance *rpc.Instance) {
+	watchClient, err := client.BoardListWatch(context.Background())
+	if err != nil {
+		log.Fatalf("Board list watch error: %s\n", err)
+	}
+
+	// Start the watcher
+	watchClient.Send(&rpc.BoardListWatchReq{
+		Instance: instance,
+	})
+
+	go func() {
+		for {
+			res, err := watchClient.Recv()
+			if err != nil {
+				log.Fatalf("Board list watch error: %s\n", err)
+			}
+
+			log.Printf("event: %s, address: %s\n", res.EventType, res.Port.Address)
+			if res.EventType == "add" {
+				log.Printf("protocol: %s, ", res.Port.Protocol)
+				log.Printf("protocolLabel: %s, ", res.Port.ProtocolLabel)
+				log.Printf("boards: %s\n\n", res.Port.Boards)
+			}
+		}
+	}()
+
+	// Watch for 10 seconds and then interrupts
+	timer := time.NewTicker(time.Duration(10 * time.Second))
+	<-timer.C
+	watchClient.Send(&rpc.BoardListWatchReq{
+		Interrupt: true,
+	})
+}
+
 func callPlatformUnInstall(client rpc.ArduinoCoreClient, instance *rpc.Instance) {
 	uninstallRespStream, err := client.PlatformUninstall(context.Background(),
 		&rpc.PlatformUninstallReq{

commands/board/list.go

@@ -108,8 +108,8 @@ func identifyViaCloudAPI(port *commands.BoardPort) ([]*rpc.BoardListItem, error)
 	return apiByVidPid(id.Get("vid"), id.Get("pid"))
 }
 
-// Identify returns a list of boards checking first the installed platforms or the Cloud API
-func Identify(pm *packagemanager.PackageManager, port *commands.BoardPort) ([]*rpc.BoardListItem, error) {
+// identify returns a list of boards checking first the installed platforms or the Cloud API
+func identify(pm *packagemanager.PackageManager, port *commands.BoardPort) ([]*rpc.BoardListItem, error) {
 	boards := []*rpc.BoardListItem{}
 
 	// first query installed cores through the Package Manager
@@ -169,7 +169,7 @@ func List(instanceID int32) (r []*rpc.DetectedPort, e error) {
 
 	retVal := []*rpc.DetectedPort{}
 	for _, port := range ports {
-		boards, err := Identify(pm, port)
+		boards, err := identify(pm, port)
 		if err != nil {
 			return nil, err
 		}
@@ -187,3 +187,52 @@ func List(instanceID int32) (r []*rpc.DetectedPort, e error) {
 
 	return retVal, nil
 }
+
+// Watch returns a channel that receives boards connection and disconnection events.
+// The discovery process can be interrupted by sending a message to the interrupt channel.
+func Watch(instanceID int32, interrupt <-chan bool) (<-chan *rpc.BoardListWatchResp, error) {
+	pm := commands.GetPackageManager(instanceID)
+	eventsChan, err := commands.WatchListBoards(pm)
+	if err != nil {
+		return nil, err
+	}
+
+	outChan := make(chan *rpc.BoardListWatchResp)
+	go func() {
+		for {
+			select {
+			case event := <-eventsChan:
+				boards := []*rpc.BoardListItem{}
+				boardsError := ""
+				if event.Type == "add" {
+					boards, err = identify(pm, &commands.BoardPort{
+						Address:             event.Port.Address,
+						Label:               event.Port.AddressLabel,
+						Prefs:               event.Port.Properties,
+						IdentificationPrefs: event.Port.IdentificationProperties,
+						Protocol:            event.Port.Protocol,
+						ProtocolLabel:       event.Port.ProtocolLabel,
+					})
+					if err != nil {
+						boardsError = err.Error()
+					}
+				}
+
+				outChan <- &rpc.BoardListWatchResp{
+					EventType: event.Type,
+					Port: &rpc.DetectedPort{
+						Address:       event.Port.Address,
+						Protocol:      event.Port.Protocol,
+						ProtocolLabel: event.Port.ProtocolLabel,
+						Boards:        boards,
+					},
+					Error: boardsError,
+				}
+			case <-interrupt:
+				break
+			}
+		}
+	}()
+
+	return outChan, nil
+}

commands/daemon/daemon.go

@@ -19,6 +19,7 @@ package daemon
 
 import (
 	"context"
+	"io"
 
 	"github.com/arduino/arduino-cli/arduino/utils"
 	"github.com/arduino/arduino-cli/commands"
@@ -58,6 +59,39 @@ func (s *ArduinoCoreServerImpl) BoardListAll(ctx context.Context, req *rpc.Board
 	return board.ListAll(ctx, req)
 }
 
+// BoardListWatch FIXMEDOC
+func (s *ArduinoCoreServerImpl) BoardListWatch(stream rpc.ArduinoCore_BoardListWatchServer) error {
+	msg, err := stream.Recv()
+	if err == io.EOF {
+		return nil
+	}
+	if err != nil {
+		return err
+	}
+
+	interrupt := make(chan bool)
+	go func() {
+		msg, err := stream.Recv()
+		if err != nil {
+			interrupt <- true
+		}
+		if msg != nil {
+			interrupt <- msg.Interrupt
+		}
+	}()
+
+	eventsChan, err := board.Watch(msg.Instance.Id, interrupt)
+	if err != nil {
+		return err
+	}
+
+	for event := range eventsChan {
+		stream.Send(event)
+	}
+
+	return nil
+}
+
 // BoardAttach FIXMEDOC
 func (s *ArduinoCoreServerImpl) BoardAttach(req *rpc.BoardAttachReq, stream rpc.ArduinoCore_BoardAttachServer) error {
 

rpc/commands/board.proto

@@ -206,6 +206,22 @@ message BoardListAllResp {
     repeated BoardListItem boards = 1;
 }
 
+message BoardListWatchReq {
+    // Arduino Core Service instance from the `Init` response.
+    Instance instance = 1;
+    // Set this to true to stop the discovery process
+    bool interrupt = 2;
+}
+
+message BoardListWatchResp {
+    // Event type as received from the serial discovery tool
+    string event_type = 1;
+    // Information about the port
+    DetectedPort port = 2;
+    // Eventual errors when detecting connected boards
+    string error = 3;
+}
+
 message BoardListItem {
     // The name for use when identifying the board to a human.
     string name = 1;

rpc/commands/commands.proto

@@ -80,6 +80,9 @@ service ArduinoCore {
   // List all the boards provided by installed platforms.
   rpc BoardListAll(BoardListAllReq) returns (BoardListAllResp);
 
+  // List boards connection and disconnected events.
+  rpc BoardListWatch(stream BoardListWatchReq) returns (stream BoardListWatchResp);
+
   // Compile an Arduino sketch.
   rpc Compile(CompileReq) returns (stream CompileResp);
 

rpc/commands/common.pb.go

@@ -16,7 +16,7 @@
 // Code generated by protoc-gen-go. DO NOT EDIT.
 // versions:
 // 	protoc-gen-go v1.25.0
-// 	protoc        v3.13.0
+// 	protoc        v3.12.4
 // source: commands/common.proto
 
 package commands

rpc/commands/compile.pb.go

@@ -16,7 +16,7 @@
 // Code generated by protoc-gen-go. DO NOT EDIT.
 // versions:
 // 	protoc-gen-go v1.25.0
-// 	protoc        v3.13.0
+// 	protoc        v3.12.4
 // source: commands/compile.proto
 
 package commands

rpc/commands/core.pb.go

@@ -16,7 +16,7 @@
 // Code generated by protoc-gen-go. DO NOT EDIT.
 // versions:
 // 	protoc-gen-go v1.25.0
-// 	protoc        v3.13.0
+// 	protoc        v3.12.4
 // source: commands/core.proto
 
 package commands

rpc/commands/lib.pb.go

@@ -16,7 +16,7 @@
 // Code generated by protoc-gen-go. DO NOT EDIT.
 // versions:
 // 	protoc-gen-go v1.25.0
-// 	protoc        v3.13.0
+// 	protoc        v3.12.4
 // source: commands/lib.proto
 
 package commands

rpc/commands/upload.pb.go

@@ -16,7 +16,7 @@
 // Code generated by protoc-gen-go. DO NOT EDIT.
 // versions:
 // 	protoc-gen-go v1.25.0
-// 	protoc        v3.13.0
+// 	protoc        v3.12.4
 // source: commands/upload.proto
 
 package commands

rpc/debug/debug.pb.go

@@ -16,7 +16,7 @@
 // Code generated by protoc-gen-go. DO NOT EDIT.
 // versions:
 // 	protoc-gen-go v1.25.0
-// 	protoc        v3.13.0
+// 	protoc        v3.12.4
 // source: debug/debug.proto
 
 package debug

rpc/monitor/monitor.pb.go

@@ -16,7 +16,7 @@
 // Code generated by protoc-gen-go. DO NOT EDIT.
 // versions:
 // 	protoc-gen-go v1.25.0
-// 	protoc        v3.13.0
+// 	protoc        v3.12.4
 // source: monitor/monitor.proto
 
 package monitor

rpc/settings/settings.pb.go

@@ -16,7 +16,7 @@
 // Code generated by protoc-gen-go. DO NOT EDIT.
 // versions:
 // 	protoc-gen-go v1.25.0
-// 	protoc        v3.13.0
+// 	protoc        v3.12.4
 // source: settings/settings.proto
 
 package settings