Accept and propagate context (#121)

* Workaround arduino-cli blocking commands

* Propagate context everywhere

* Fix

* stash

* Adjust iot package

* Fix cancellation leak

* Use context in listfqbn

Author: polldo

arduino/cli/commander.go

@@ -44,9 +44,11 @@ type commander struct {
 func NewCommander() (arduino.Commander, error) {
 	// Discard arduino-cli log info messages
 	logrus.SetLevel(logrus.ErrorLevel)
-	// Initialize arduino-cli configuration
+
+	// Initialize arduino-cli configuration.
 	configuration.Settings = configuration.Init(configuration.FindConfigFileInArgsOrWorkingDirectory(os.Args))
-	// Create arduino-cli instance, needed to execute arduino-cli commands
+
+	// Create and init an arduino-cli instance, needed to execute arduino-cli commands.
 	inst, err := instance.Create()
 	if err != nil {
 		err = fmt.Errorf("creating arduino-cli instance: %w", err)
@@ -61,34 +63,64 @@ func NewCommander() (arduino.Commander, error) {
 	return cmd, nil
 }
 
+func mergeErrors(err error, errs []error) error {
+	merr := errors.New("merged errors: ")
+	empty := true
+
+	if err != nil {
+		merr = fmt.Errorf("%w%v; ", merr, err)
+		empty = false
+	}
+
+	if len(errs) > 0 {
+		empty = false
+		for _, e := range errs {
+			merr = fmt.Errorf("%w%v; ", merr, e)
+		}
+	}
+
+	if !empty {
+		return merr
+	}
+	return nil
+}
+
 // BoardList executes the 'arduino-cli board list' command
 // and returns its result.
-func (c *commander) BoardList() ([]*rpc.DetectedPort, error) {
+func (c *commander) BoardList(ctx context.Context) ([]*rpc.DetectedPort, error) {
 	req := &rpc.BoardListRequest{
 		Instance: c.Instance,
 		Timeout:  time.Second.Milliseconds(),
 	}
 
-	ports, errs, err := board.List(req)
-	if err != nil {
-		err = fmt.Errorf("%s: %w", "detecting boards", err)
-		return nil, err
+	// There is no obvious way to cancel the execution of this command.
+	// So, we execute it in a goroutine and leave it running alone if ctx gets cancelled.
+	type resp struct {
+		err   error
+		ports []*rpc.DetectedPort
 	}
+	quit := make(chan resp, 1)
+	go func() {
+		ports, errs, err := board.List(req)
+		quit <- resp{err: mergeErrors(err, errs), ports: ports}
+		close(quit)
+	}()
 
-	if len(errs) > 0 {
-		err = errors.New("starting discovery procedure: received errors: ")
-		for _, e := range errs {
-			err = fmt.Errorf("%w%v; ", err, e)
+	// Wait for the command to complete or the context to be terminated.
+	select {
+	case <-ctx.Done():
+		return nil, errors.New("board list command cancelled")
+	case r := <-quit:
+		if r.err != nil {
+			return nil, fmt.Errorf("executing board list command: %w", r.err)
 		}
-		return nil, err
+		return r.ports, nil
 	}
-
-	return ports, nil
 }
 
 // UploadBin executes the 'arduino-cli upload -i' command
 // and returns its result.
-func (c *commander) UploadBin(fqbn, bin, address, protocol string) error {
+func (c *commander) UploadBin(ctx context.Context, fqbn, bin, address, protocol string) error {
 	req := &rpc.UploadRequest{
 		Instance:   c.Instance,
 		Fqbn:       fqbn,
@@ -97,11 +129,25 @@ func (c *commander) UploadBin(fqbn, bin, address, protocol string) error {
 		Port:       &rpc.Port{Address: address, Protocol: protocol},
 		Verbose:    false,
 	}
-
 	l := logrus.StandardLogger().WithField("source", "arduino-cli").Writer()
-	if _, err := upload.Upload(context.Background(), req, l, l); err != nil {
-		err = fmt.Errorf("%s: %w", "uploading binary", err)
-		return err
+
+	// There is no obvious way to cancel the execution of this command.
+	// So, we execute it in a goroutine and leave it running if ctx gets cancelled.
+	quit := make(chan error, 1)
+	go func() {
+		_, err := upload.Upload(ctx, req, l, l)
+		quit <- err
+		close(quit)
+	}()
+
+	// Wait for the upload to complete or the context to be terminated.
+	select {
+	case <-ctx.Done():
+		return errors.New("upload cancelled")
+	case err := <-quit:
+		if err != nil {
+			return fmt.Errorf("uploading binary: %w", err)
+		}
+		return nil
 	}
-	return nil
 }

arduino/commander.go

@@ -18,13 +18,15 @@
 package arduino
 
 import (
+	"context"
+
 	rpc "github.com/arduino/arduino-cli/rpc/cc/arduino/cli/commands/v1"
 )
 
 // Commander of arduino package allows to call
 // the arduino-cli commands in a programmatic way.
 type Commander interface {
-	BoardList() ([]*rpc.DetectedPort, error)
-	UploadBin(fqbn, bin, address, protocol string) error
+	BoardList(ctx context.Context) ([]*rpc.DetectedPort, error)
+	UploadBin(ctx context.Context, fqbn, bin, address, protocol string) error
 	//Compile() error
 }

arduino/grpc/board.go

@@ -30,7 +30,7 @@ type boardHandler struct {
 
 // BoardList executes the 'arduino-cli board list' command
 // and returns its result.
-func (b boardHandler) BoardList() ([]*rpc.DetectedPort, error) {
+func (b boardHandler) BoardList(ctx context.Context) ([]*rpc.DetectedPort, error) {
 	boardListResp, err := b.serviceClient.BoardList(context.Background(),
 		&rpc.BoardListRequest{Instance: b.instance})
 

arduino/grpc/compile.go

@@ -38,7 +38,7 @@ func (c compileHandler) Compile() error {
 
 // Upload executes the 'arduino-cli upload -i' command
 // and returns its result.
-func (c compileHandler) UploadBin(fqbn, bin, address, protocol string) error {
+func (c compileHandler) UploadBin(ctx context.Context, fqbn, bin, address, protocol string) error {
 	stream, err := c.serviceClient.Upload(context.Background(),
 		&rpc.UploadRequest{
 			Instance:   c.instance,

cli/dashboard/create.go

@@ -18,6 +18,7 @@
 package dashboard
 
 import (
+	"context"
 	"fmt"
 	"os"
 	"strings"
@@ -76,7 +77,7 @@ func runCreateCommand(flags *createFlags) error {
 		params.Name = &flags.name
 	}
 
-	dashboard, err := dashboard.Create(params, cred)
+	dashboard, err := dashboard.Create(context.TODO(), params, cred)
 	if err != nil {
 		return err
 	}

cli/dashboard/delete.go

@@ -18,6 +18,7 @@
 package dashboard
 
 import (
+	"context"
 	"fmt"
 	"os"
 
@@ -60,7 +61,7 @@ func runDeleteCommand(flags *deleteFlags) error {
 	}
 
 	params := &dashboard.DeleteParams{ID: flags.id}
-	err = dashboard.Delete(params, cred)
+	err = dashboard.Delete(context.TODO(), params, cred)
 	if err != nil {
 		return err
 	}

cli/dashboard/extract.go

@@ -18,6 +18,7 @@
 package dashboard
 
 import (
+	"context"
 	"fmt"
 	"os"
 
@@ -64,7 +65,7 @@ func runExtractCommand(flags *extractFlags) error {
 		ID: flags.id,
 	}
 
-	template, err := dashboard.Extract(params, cred)
+	template, err := dashboard.Extract(context.TODO(), params, cred)
 	if err != nil {
 		return err
 	}

cli/dashboard/list.go

@@ -18,6 +18,7 @@
 package dashboard
 
 import (
+	"context"
 	"fmt"
 	"math"
 	"os"
@@ -66,7 +67,7 @@ func runListCommand(flags *listFlags) error {
 		return fmt.Errorf("retrieving credentials: %w", err)
 	}
 
-	dash, err := dashboard.List(cred)
+	dash, err := dashboard.List(context.TODO(), cred)
 	if err != nil {
 		return err
 	}

cli/device/create.go

@@ -18,6 +18,7 @@
 package device
 
 import (
+	"context"
 	"fmt"
 	"os"
 
@@ -27,6 +28,7 @@ import (
 	"github.com/arduino/arduino-cloud-cli/config"
 	"github.com/sirupsen/logrus"
 	"github.com/spf13/cobra"
+	"go.bug.st/cleanup"
 )
 
 type createFlags struct {
@@ -73,7 +75,10 @@ func runCreateCommand(flags *createFlags) error {
 		params.FQBN = &flags.fqbn
 	}
 
-	dev, err := device.Create(params, cred)
+	ctx, cancel := cleanup.InterruptableContext(context.Background())
+	defer cancel()
+
+	dev, err := device.Create(ctx, params, cred)
 	if err != nil {
 		return err
 	}

cli/device/creategeneric.go

@@ -18,6 +18,7 @@
 package device
 
 import (
+	"context"
 	"fmt"
 	"os"
 
@@ -27,6 +28,7 @@ import (
 	"github.com/arduino/arduino-cloud-cli/config"
 	"github.com/sirupsen/logrus"
 	"github.com/spf13/cobra"
+	"go.bug.st/cleanup"
 )
 
 type createGenericFlags struct {
@@ -66,7 +68,10 @@ func runCreateGenericCommand(flags *createGenericFlags) error {
 		FQBN: flags.fqbn,
 	}
 
-	dev, err := device.CreateGeneric(params, cred)
+	ctx, cancel := cleanup.InterruptableContext(context.Background())
+	defer cancel()
+
+	dev, err := device.CreateGeneric(ctx, params, cred)
 	if err != nil {
 		return err
 	}