Implement steering/throttle reading from simulator

pkg/controls/controls.go

@@ -0,0 +1,123 @@
+package controls
+
+import (
+	"bufio"
+	"encoding/json"
+	"fmt"
+	"github.com/cyrilix/robocar-protobuf/go/events"
+	"github.com/cyrilix/robocar-simulator/pkg/simulator"
+	log "github.com/sirupsen/logrus"
+	"io"
+	"net"
+	"sync"
+)
+
+type SteeringController interface {
+ 	WriteSteering(message *events.SteeringMessage)
+}
+
+type ThrottleController interface {
+	WriteThrottle(message *events.ThrottleMessage)
+}
+
+func New(address string) (*Gateway, error) {
+	conn, err := net.Dial("tcp", address)
+	if err != nil {
+		return nil, fmt.Errorf("unable to connect to %v", address)
+	}
+	return &Gateway{
+		conn:  conn,
+	}, nil
+}
+
+/* Simulator interface to publish command controls from mqtt topic */
+type Gateway struct {
+	cancel           chan interface{}
+
+	muControl   sync.Mutex
+	lastControl *simulator.ControlMsg
+	conn        io.WriteCloser
+}
+
+func (g *Gateway) Start() {
+	log.Info("connect to simulator")
+	g.cancel = make(chan interface{})
+}
+
+func (g *Gateway) Stop() {
+	log.Info("close simulator gateway")
+	close(g.cancel)
+
+	if err := g.Close(); err != nil {
+		log.Printf("unexpected error while simulator connection is closed: %v", err)
+	}
+}
+
+func (g *Gateway) Close() error {
+	if g.conn == nil {
+		log.Warnln("no connection to close")
+		return nil
+	}
+	if err := g.conn.Close(); err != nil {
+		return fmt.Errorf("unable to close connection to simulator: %v", err)
+	}
+	return nil
+}
+
+func (g *Gateway) WriteSteering(message *events.SteeringMessage) {
+	g.muControl.Lock()
+	defer g.muControl.Unlock()
+	g.initLastControlMsg()
+
+	g.lastControl.Steering = message.Steering
+	g.writeContent()
+}
+
+func (g *Gateway) WriteThrottle(message *events.ThrottleMessage) {
+	g.muControl.Lock()
+	defer g.muControl.Unlock()
+	g.initLastControlMsg()
+
+	if message.Throttle > 0 {
+		g.lastControl.Throttle = message.Throttle
+		g.lastControl.Brake = 0.
+	} else {
+		g.lastControl.Throttle = 0.
+		g.lastControl.Brake = -1 * message.Throttle
+	}
+
+	g.writeContent()
+}
+
+func (g *Gateway) writeContent() {
+	w := bufio.NewWriter(g.conn)
+	content, err := json.Marshal(g.lastControl)
+	if err != nil {
+		log.Errorf("unable to marshall control msg \"%#v\": %v", g.lastControl, err)
+		return
+	}
+
+	_, err = w.Write(append(content, '\n'))
+	if err != nil {
+		log.Errorf("unable to write control msg \"%#v\" to simulator: %v", g.lastControl, err)
+		return
+	}
+	err = w.Flush()
+	if err != nil {
+		log.Errorf("unable to flush control msg \"%#v\" to simulator: %v", g.lastControl, err)
+		return
+	}
+}
+
+func (g *Gateway) initLastControlMsg() {
+	if g.lastControl != nil {
+		return
+	}
+	g.lastControl = &simulator.ControlMsg{
+		MsgType:  "control",
+		Steering: 0.,
+		Throttle: 0.,
+		Brake:    0.,
+	}
+}
+

pkg/controls/controls_test.go

@@ -0,0 +1,281 @@
+package controls
+
+import (
+	"bufio"
+	"encoding/json"
+	"fmt"
+	"github.com/cyrilix/robocar-protobuf/go/events"
+	"github.com/cyrilix/robocar-simulator/pkg/simulator"
+	log "github.com/sirupsen/logrus"
+	"io"
+	"net"
+	"sync"
+	"testing"
+)
+
+func TestGateway_WriteSteering(t *testing.T) {
+
+	cases := []struct {
+		name        string
+		msg         *events.SteeringMessage
+		previousMsg *simulator.ControlMsg
+		expectedMsg simulator.ControlMsg
+	}{
+		{"First Message",
+			&events.SteeringMessage{Steering: 0.5, Confidence: 1},
+			nil,
+			simulator.ControlMsg{
+				MsgType:  "control",
+				Steering: 0.5,
+				Throttle: 0,
+				Brake:    0,
+			}},
+		{"Update steering",
+			&events.SteeringMessage{Steering: -0.5, Confidence: 1},
+			&simulator.ControlMsg{
+				MsgType:  "control",
+				Steering: 0.2,
+				Throttle: 0,
+				Brake:    0,
+			},
+			simulator.ControlMsg{
+				MsgType:  "control",
+				Steering: -0.5,
+				Throttle: 0,
+				Brake:    0,
+			}},
+		{"Update steering shouldn't erase throttle value",
+			&events.SteeringMessage{Steering: -0.3, Confidence: 1},
+			&simulator.ControlMsg{
+				MsgType:  "control",
+				Steering: 0.2,
+				Throttle: 0.6,
+				Brake:    0.1,
+			},
+			simulator.ControlMsg{
+				MsgType:  "control",
+				Steering: -0.3,
+				Throttle: 0.6,
+				Brake:    0.1,
+			}},
+	}
+
+	simulatorMock := ConnMock{}
+	err := simulatorMock.listen()
+	if err != nil {
+		t.Errorf("unable to start mock server: %v", err)
+	}
+	defer func(){
+		if err := simulatorMock.Close(); err != nil {
+			t.Errorf("unable to stop simulator mock: %v", err)
+		}
+	}()
+
+	server, err := New(simulatorMock.Addr())
+	if err != nil {
+		t.Fatalf("unable to init simulator gateway: %v", err)
+	}
+
+	for _, c := range cases {
+		server.lastControl = c.previousMsg
+
+		server.WriteSteering(c.msg)
+
+		ctrlMsg := <- simulatorMock.Notify()
+		if *ctrlMsg != c.expectedMsg {
+			t.Errorf("[%v] bad messge received: %#v, wants %#v", c.name, ctrlMsg, c.expectedMsg)
+		}
+	}
+}
+
+func TestGateway_WriteThrottle(t *testing.T) {
+
+	cases := []struct {
+		name        string
+		msg         *events.ThrottleMessage
+		previousMsg *simulator.ControlMsg
+		expectedMsg simulator.ControlMsg
+	}{
+		{"First Message",
+			&events.ThrottleMessage{Throttle: 0.5, Confidence: 1},
+			nil,
+			simulator.ControlMsg{
+				MsgType:  "control",
+				Steering: 0,
+				Throttle: 0.5,
+				Brake:    0,
+			}},
+		{"Update Throttle",
+			&events.ThrottleMessage{Throttle: 0.6, Confidence: 1},
+			&simulator.ControlMsg{
+				MsgType:  "control",
+				Steering: 0,
+				Throttle: 0.4,
+				Brake:    0,
+			},
+			simulator.ControlMsg{
+				MsgType:  "control",
+				Steering: 0,
+				Throttle: 0.6,
+				Brake:    0,
+			}},
+		{"Update steering shouldn't erase throttle value",
+			&events.ThrottleMessage{Throttle: 0.3, Confidence: 1},
+			&simulator.ControlMsg{
+				MsgType:  "control",
+				Steering: 0.2,
+				Throttle: 0.6,
+				Brake:    0.,
+			},
+			simulator.ControlMsg{
+				MsgType:  "control",
+				Steering: 0.2,
+				Throttle: 0.3,
+				Brake:    0.,
+			}},
+		{"Throttle to brake",
+			&events.ThrottleMessage{Throttle: -0.7, Confidence: 1},
+			&simulator.ControlMsg{
+				MsgType:  "control",
+				Steering: 0.2,
+				Throttle: 0.6,
+				Brake:    0.,
+			},
+			simulator.ControlMsg{
+				MsgType:  "control",
+				Steering: 0.2,
+				Throttle: 0.,
+				Brake:    0.7,
+			}},
+		{"Update brake",
+			&events.ThrottleMessage{Throttle: -0.2, Confidence: 1},
+			&simulator.ControlMsg{
+				MsgType:  "control",
+				Steering: 0.2,
+				Throttle: 0.,
+				Brake:    0.5,
+			},
+			simulator.ControlMsg{
+				MsgType:  "control",
+				Steering: 0.2,
+				Throttle: 0.,
+				Brake:    0.2,
+			}},
+		{"Brake to throttle",
+			&events.ThrottleMessage{Throttle: 0.9, Confidence: 1},
+			&simulator.ControlMsg{
+				MsgType:  "control",
+				Steering: 0.2,
+				Throttle: 0.,
+				Brake:    0.4,
+			},
+			simulator.ControlMsg{
+				MsgType:  "control",
+				Steering: 0.2,
+				Throttle: 0.9,
+				Brake:    0.,
+			}},
+	}
+
+	simulatorMock := ConnMock{}
+	err := simulatorMock.listen()
+	if err != nil {
+		t.Errorf("unable to start mock server: %v", err)
+	}
+	defer func(){
+		if err := simulatorMock.Close(); err != nil {
+			t.Errorf("unable to stop simulator mock: %v", err)
+		}
+	}()
+
+	server, err := New(simulatorMock.Addr())
+	if err != nil {
+		t.Fatalf("unable to init simulator gateway: %v", err)
+	}
+
+	for _, c := range cases {
+		server.lastControl = c.previousMsg
+
+		server.WriteThrottle(c.msg)
+
+		ctrlMsg := <- simulatorMock.Notify()
+		if *ctrlMsg != c.expectedMsg {
+			t.Errorf("[%v] bad messge received: %#v, wants %#v", c.name, ctrlMsg, c.expectedMsg)
+		}
+	}
+}
+
+type ConnMock struct {
+	initMsgsOnce sync.Once
+
+	ln             net.Listener
+	notifyChan     chan *simulator.ControlMsg
+	initNotifyChan sync.Once
+}
+
+func (c *ConnMock) Notify() <-chan *simulator.ControlMsg {
+	c.initNotifyChan.Do(func() { c.notifyChan = make(chan *simulator.ControlMsg) })
+	return c.notifyChan
+}
+
+func (c *ConnMock) listen() error {
+	ln, err := net.Listen("tcp", "127.0.0.1:")
+	c.ln = ln
+	if err != nil {
+
+		return fmt.Errorf("unable to listen on port: %v", err)
+	}
+
+	go func() {
+		for {
+			conn, err := c.ln.Accept()
+			if err != nil {
+				log.Infof("connection close: %v", err)
+				break
+			}
+			go c.handleConnection(conn)
+		}
+	}()
+	return nil
+}
+
+func (c *ConnMock) Addr() string {
+	return c.ln.Addr().String()
+}
+
+func (c *ConnMock) handleConnection(conn net.Conn) {
+	c.initNotifyChan.Do(func() { c.notifyChan = make(chan *simulator.ControlMsg) })
+	reader := bufio.NewReader(conn)
+	for {
+		rawCmd, err := reader.ReadBytes('\n')
+		if err != nil {
+			if err == io.EOF {
+				log.Info("connection closed")
+				break
+			}
+			log.Errorf("unable to read request: %v", err)
+			return
+		}
+
+		var msg simulator.ControlMsg
+		err = json.Unmarshal(rawCmd, &msg)
+		if err != nil {
+			log.Errorf("unable to unmarchal control msg \"%v\": %v", string(rawCmd), err)
+			continue
+		}
+
+		c.notifyChan <- &msg
+	}
+}
+
+func (c *ConnMock) Close() error {
+	log.Infof("close mock server")
+	err := c.ln.Close()
+	if err != nil {
+		return fmt.Errorf("unable to close mock server: %v", err)
+	}
+	if c.notifyChan != nil {
+		close(c.notifyChan)
+	}
+	return nil
+}

pkg/gateway/gateway.go

@@ -0,0 +1,247 @@
+package gateway
+
+import (
+	"bufio"
+	"encoding/json"
+	"fmt"
+	"github.com/avast/retry-go"
+	"github.com/cyrilix/robocar-protobuf/go/events"
+	"github.com/cyrilix/robocar-simulator/pkg/simulator"
+	mqtt "github.com/eclipse/paho.mqtt.golang"
+	"github.com/golang/protobuf/proto"
+	"github.com/golang/protobuf/ptypes/timestamp"
+	log "github.com/sirupsen/logrus"
+	"io"
+	"net"
+	"time"
+)
+
+func New(publisher Publisher, addressSimulator string) *Gateway {
+	l := log.WithField("simulator", addressSimulator)
+	l.Info("run gateway from simulator")
+
+	return &Gateway{
+		address:   addressSimulator,
+		publisher: publisher,
+		log:       l,
+	}
+}
+
+/* Simulator interface to publish gateway frames into mqtt topicFrame */
+type Gateway struct {
+	cancel chan interface{}
+
+	address string
+	conn    io.ReadCloser
+
+	publisher Publisher
+	log       *log.Entry
+}
+
+func (p *Gateway) Start() error {
+	p.log.Info("connect to simulator")
+	p.cancel = make(chan interface{})
+	msgChan := make(chan *simulator.TelemetryMsg)
+
+	go p.run(msgChan)
+
+	for {
+		select {
+		case msg := <-msgChan:
+			go p.publishFrame(msg)
+			go p.publishInputSteering(msg)
+			go p.publishInputThrottle(msg)
+		case <-p.cancel:
+			return nil
+		}
+	}
+}
+
+func (p *Gateway) Stop() {
+	p.log.Info("close simulator gateway")
+	close(p.cancel)
+
+	if err := p.Close(); err != nil {
+		p.log.Warnf("unexpected error while simulator connection is closed: %v", err)
+	}
+}
+
+func (p *Gateway) Close() error {
+	if p.conn == nil {
+		p.log.Warn("no connection to close")
+		return nil
+	}
+	if err := p.conn.Close(); err != nil {
+		return fmt.Errorf("unable to close connection to simulator: %v", err)
+	}
+	return nil
+}
+
+func (p *Gateway) run(msgChan chan<- *simulator.TelemetryMsg) {
+	err := retry.Do(func() error {
+		p.log.Info("connect to simulator")
+		conn, err := connect(p.address)
+		if err != nil {
+			return fmt.Errorf("unable to connect to simulator at %v", p.address)
+		}
+		p.conn = conn
+		p.log.Info("connection success")
+		return nil
+	},
+		retry.Delay(1*time.Second),
+	)
+	if err != nil {
+		p.log.Panicf("unable to connect to simulator: %v", err)
+	}
+
+	reader := bufio.NewReader(p.conn)
+
+	err = retry.Do(
+		func() error { return p.listen(msgChan, reader) },
+	)
+	if err != nil {
+		p.log.Errorf("unable to connect to server: %v", err)
+	}
+}
+
+func (p *Gateway) listen(msgChan chan<- *simulator.TelemetryMsg, reader *bufio.Reader) error {
+	for {
+		rawLine, err := reader.ReadBytes('\n')
+		if err == io.EOF {
+			p.log.Info("Connection closed")
+			return err
+		}
+		if err != nil {
+			return fmt.Errorf("unable to read response: %v", err)
+		}
+
+		var msg simulator.TelemetryMsg
+		err = json.Unmarshal(rawLine, &msg)
+		if err != nil {
+			p.log.Errorf("unable to unmarshal simulator msg '%v': %v", string(rawLine), err)
+		}
+		if "telemetry" != msg.MsgType {
+			continue
+		}
+		msgChan <- &msg
+	}
+}
+
+func (p *Gateway) publishFrame(msgSim *simulator.TelemetryMsg) {
+	now := time.Now()
+	msg := &events.FrameMessage{
+		Id: &events.FrameRef{
+			Name: "gateway",
+			Id:   fmt.Sprintf("%d%03d", now.Unix(), now.Nanosecond()/1000/1000),
+			CreatedAt: &timestamp.Timestamp{
+				Seconds: now.Unix(),
+				Nanos:   int32(now.Nanosecond()),
+			},
+		},
+		Frame: msgSim.Image,
+	}
+
+	log.Debugf("publish frame '%v/%v'", msg.Id.Name, msg.Id.Id)
+	payload, err := proto.Marshal(msg)
+	if err != nil {
+		p.log.Errorf("unable to marshal protobuf message: %v", err)
+	}
+	p.publisher.PublishFrame(payload)
+}
+
+func (p *Gateway) publishInputSteering(msgSim *simulator.TelemetryMsg) {
+	steering := &events.SteeringMessage{
+		Steering:  float32(msgSim.SteeringAngle),
+		Confidence: 1.0,
+	}
+
+	log.Debugf("publish steering '%v'", steering.Steering)
+	payload, err := proto.Marshal(steering)
+	if err != nil {
+		p.log.Errorf("unable to marshal protobuf message: %v", err)
+	}
+	p.publisher.PublishSteering(payload)
+}
+
+func (p *Gateway) publishInputThrottle(msgSim *simulator.TelemetryMsg) {
+	steering := &events.ThrottleMessage{
+		Throttle:  float32(msgSim.Throttle),
+		Confidence: 1.0,
+	}
+
+	log.Debugf("publish throttle '%v'", steering.Throttle)
+	payload, err := proto.Marshal(steering)
+	if err != nil {
+		p.log.Errorf("unable to marshal protobuf message: %v", err)
+	}
+	p.publisher.PublishThrottle(payload)
+}
+
+var connect = func(address string) (io.ReadWriteCloser, error) {
+	conn, err := net.Dial("tcp", address)
+	if err != nil {
+		return nil, fmt.Errorf("unable to connect to %v", address)
+	}
+	return conn, nil
+}
+
+type Publisher interface {
+	PublishFrame(payload []byte)
+	PublishThrottle(payload []byte)
+	PublishSteering(payload []byte)
+}
+
+func NewMqttPublisher(client mqtt.Client, topicFrame, topicThrottle, topicSteering string) Publisher {
+	return &MqttPublisher{
+		client:     client,
+		topicFrame: topicFrame,
+		topicSteering: topicSteering,
+		topicThrottle: topicThrottle,
+	}
+}
+
+type MqttPublisher struct {
+	client     mqtt.Client
+	topicFrame string
+	topicSteering string
+	topicThrottle string
+}
+
+func (m *MqttPublisher) PublishThrottle(payload []byte) {
+	if m.topicThrottle == "" {
+		return
+	}
+	err := m.publish(m.topicThrottle, payload)
+	if err != nil {
+		log.Errorf("unable to publish throttle: %v", err)
+	}
+}
+
+func (m *MqttPublisher) PublishSteering(payload []byte) {
+	if m.topicSteering == "" {
+		return
+	}
+	err := m.publish(m.topicSteering, payload)
+	if err != nil {
+		log.Errorf("unable to publish steering: %v", err)
+	}
+}
+
+func (m *MqttPublisher) PublishFrame(payload []byte) {
+	if m.topicFrame == "" {
+		return
+	}
+	err := m.publish(m.topicFrame, payload)
+	if err != nil {
+		log.Errorf("unable to publish frame: %v", err)
+	}
+}
+
+func (m *MqttPublisher) publish(topic string, payload []byte) error {
+	token := m.client.Publish(topic, 0, false, payload)
+	token.WaitTimeout(10 * time.Millisecond)
+	if err := token.Error(); err != nil {
+		return fmt.Errorf("unable to publish to topic: %v", err)
+	}
+	return nil
+}

pkg/gateway/gateway_test.go

@@ -0,0 +1,289 @@
+package gateway
+
+import (
+	"bufio"
+	"encoding/json"
+	"fmt"
+	"github.com/cyrilix/robocar-protobuf/go/events"
+	"github.com/golang/protobuf/proto"
+	log "github.com/sirupsen/logrus"
+	"io"
+	"io/ioutil"
+	"net"
+	"strings"
+	"sync"
+	"testing"
+	"time"
+)
+
+type MockPublisher struct {
+	notifyFrameChan        chan []byte
+	initNotifyFrameChan    sync.Once
+	notifySteeringChan     chan []byte
+	initNotifySteeringChan sync.Once
+	notifyThrottleChan     chan []byte
+	initNotifyThrottleChan sync.Once
+}
+
+func (p *MockPublisher) Close() error {
+	if p.notifyFrameChan != nil {
+		close(p.notifyFrameChan)
+	}
+	if p.notifyThrottleChan != nil {
+		close(p.notifyThrottleChan)
+	}
+	if p.notifySteeringChan != nil {
+		close(p.notifySteeringChan)
+	}
+	return nil
+}
+
+func (p *MockPublisher) PublishFrame(payload []byte) {
+	p.notifyFrameChan <- payload
+}
+func (p *MockPublisher) PublishSteering(payload []byte) {
+	p.notifySteeringChan <- payload
+}
+func (p *MockPublisher) PublishThrottle(payload []byte) {
+	p.notifyThrottleChan <- payload
+}
+
+func (p *MockPublisher) NotifyFrame() <-chan []byte {
+	p.initNotifyFrameChan.Do(func() { p.notifyFrameChan = make(chan []byte) })
+	return p.notifyFrameChan
+}
+func (p *MockPublisher) NotifySteering() <-chan []byte {
+	p.initNotifySteeringChan.Do(func() { p.notifySteeringChan = make(chan []byte) })
+	return p.notifySteeringChan
+}
+func (p *MockPublisher) NotifyThrottle() <-chan []byte {
+	p.initNotifyThrottleChan.Do(func() { p.notifyThrottleChan = make(chan []byte) })
+	return p.notifyThrottleChan
+}
+
+func TestPart_ListenEvents(t *testing.T) {
+	simulatorMock := SimulatorMock{}
+	err := simulatorMock.Start()
+	if err != nil {
+		t.Errorf("unable to start mock server: %v", err)
+	}
+	defer func() {
+		if err := simulatorMock.Close(); err != nil {
+			t.Errorf("unable to close mock server: %v", err)
+		}
+	}()
+
+	publisher := MockPublisher{}
+
+	part := New(&publisher, simulatorMock.Addr())
+	go func() {
+		err := part.Start()
+		if err != nil {
+			t.Fatalf("unable to start gateway simulator: %v", err)
+		}
+	}()
+	defer func() {
+		if err := part.Close(); err != nil {
+			t.Errorf("unable to close gateway simulator: %v", err)
+		}
+	}()
+
+	simulatorMock.WaitConnection()
+	log.Trace("read test data")
+	testContent, err := ioutil.ReadFile("testdata/msg.json")
+	lines := strings.Split(string(testContent), "\n")
+
+	for idx, line := range lines {
+		err = simulatorMock.EmitMsg(line)
+		if err != nil {
+			t.Errorf("[line %v/%v] unable to write line: %v", idx+1, len(lines), err)
+		}
+
+		eventsType := map[string]bool{"frame": false, "steering": false, "throttle": false}
+		nbEventsExpected := len(eventsType)
+		wg := sync.WaitGroup{}
+		// Expect number mqtt event
+
+		wg.Add(nbEventsExpected)
+		finished := make(chan struct{})
+		go func() {
+			wg.Wait()
+			finished <- struct{}{}
+		}()
+
+		timeout := time.Tick(100 * time.Millisecond)
+
+		endLoop := false
+		for {
+			select {
+			case byteMsg := <-publisher.NotifyFrame():
+				checkFrame(t, byteMsg)
+				eventsType["frame"] = true
+				wg.Done()
+			case byteMsg := <-publisher.NotifySteering():
+				checkSteering(t, byteMsg, line)
+				eventsType["steering"] = true
+				wg.Done()
+			case byteMsg := <-publisher.NotifyThrottle():
+				checkThrottle(t, byteMsg, line)
+				eventsType["throttle"] = true
+				wg.Done()
+			case <-finished:
+				log.Trace("loop ended")
+				endLoop = true
+			case <-timeout:
+				t.Errorf("not all event are published")
+				t.FailNow()
+			}
+			if endLoop {
+				break
+			}
+		}
+		for k, v := range eventsType {
+			if !v {
+				t.Errorf("no %v event published for line %v", k, line)
+			}
+		}
+	}
+}
+
+
+func checkFrame(t *testing.T, byteMsg []byte) {
+	var msg events.FrameMessage
+	err := proto.Unmarshal(byteMsg, &msg)
+	if err != nil {
+		t.Errorf("unable to unmarshal frame msg: %v", err)
+	}
+	if msg.GetId() == nil {
+		t.Error("frame msg has not Id")
+	}
+	if len(msg.Frame) < 10 {
+		t.Errorf("[%v] invalid frame image: %v", msg.Id, msg.GetFrame())
+	}
+}
+func checkSteering(t *testing.T, byteMsg []byte, rawLine string) {
+	var input map[string]interface{}
+	err := json.Unmarshal([]byte(rawLine), &input)
+	if err != nil {
+		t.Fatalf("unable to parse input data '%v': %v", rawLine, err)
+	}
+	steering := input["steering_angle"].(float64)
+	expectedSteering := float32(steering)
+
+	var msg events.SteeringMessage
+	err = proto.Unmarshal(byteMsg, &msg)
+	if err != nil {
+		t.Errorf("unable to unmarshal steering msg: %v", err)
+	}
+
+	if msg.GetSteering() != expectedSteering{
+		t.Errorf("invalid steering value: %f, wants %f", msg.GetSteering(), expectedSteering)
+	}
+	if msg.Confidence != 1.0 {
+		t.Errorf("invalid steering confidence: %f, wants %f", msg.Confidence, 1.0)
+	}
+}
+
+func checkThrottle(t *testing.T, byteMsg []byte, rawLine string) {
+	var input map[string]interface{}
+	err := json.Unmarshal([]byte(rawLine), &input)
+	if err != nil {
+		t.Fatalf("unable to parse input data '%v': %v", rawLine, err)
+	}
+	throttle := input["throttle"].(float64)
+	expectedThrottle := float32(throttle)
+
+	var msg events.SteeringMessage
+	err = proto.Unmarshal(byteMsg, &msg)
+	if err != nil {
+		t.Errorf("unable to unmarshal throttle msg: %v", err)
+	}
+
+	if msg.GetSteering() != expectedThrottle {
+		t.Errorf("invalid throttle value: %f, wants %f", msg.GetSteering(), expectedThrottle)
+	}
+	if msg.Confidence != 1.0 {
+		t.Errorf("invalid throttle confidence: %f, wants %f", msg.Confidence, 1.0)
+	}
+}
+
+type SimulatorMock struct {
+	ln            net.Listener
+	muConn        sync.Mutex
+	conn          net.Conn
+	writer        *bufio.Writer
+	newConnection chan net.Conn
+	logger        *log.Entry
+}
+
+func (c *SimulatorMock) EmitMsg(p string) (err error) {
+	c.muConn.Lock()
+	defer c.muConn.Unlock()
+	_, err = c.writer.WriteString(p + "\n")
+	if err != nil {
+		c.logger.Errorf("unable to write response: %v", err)
+	}
+	if err == io.EOF {
+		c.logger.Info("Connection closed")
+		return err
+	}
+	err = c.writer.Flush()
+	return err
+}
+
+func (c *SimulatorMock) WaitConnection() {
+	c.muConn.Lock()
+	defer c.muConn.Unlock()
+	c.logger.Debug("simulator waiting connection")
+	if c.conn != nil {
+		return
+	}
+	c.logger.Debug("new connection")
+	conn := <-c.newConnection
+
+	c.conn = conn
+	c.writer = bufio.NewWriter(conn)
+}
+
+func (c *SimulatorMock) Start() error {
+	c.logger = log.WithField("simulator", "mock")
+	c.newConnection = make(chan net.Conn)
+	ln, err := net.Listen("tcp", "127.0.0.1:")
+	c.ln = ln
+	if err != nil {
+		return fmt.Errorf("unable to listen on port: %v", err)
+	}
+	go func() {
+		for {
+			conn, err := c.ln.Accept()
+			if err != nil && err == io.EOF {
+				c.logger.Errorf("connection close: %v", err)
+				break
+			}
+			if c.newConnection == nil {
+				break
+			}
+			c.newConnection <- conn
+		}
+	}()
+	return nil
+}
+
+func (c *SimulatorMock) Addr() string {
+	return c.ln.Addr().String()
+}
+
+func (c *SimulatorMock) Close() error {
+	c.logger.Debug("close mock server")
+
+	if c == nil {
+		return nil
+	}
+	close(c.newConnection)
+	c.newConnection = nil
+	err := c.ln.Close()
+	if err != nil {
+		return fmt.Errorf("unable to close mock server: %v", err)
+	}
+	return nil
+}

pkg/simulator/simulator.go.go

@@ -0,0 +1,23 @@
+package simulator
+
+type TelemetryMsg struct {
+	MsgType       string  `json:"msg_type"`
+	SteeringAngle float64 `json:"steering_angle"`
+	Throttle      float64 `json:"throttle"`
+	Speed         float64 `json:"speed"`
+	Image         []byte  `json:"image"`
+	Hit           string  `json:"hit"`
+	PosX          float64 `json:"pos_x"`
+	PosY          float64 `json:"posy"`
+	PosZ          float64 `json:"pos_z"`
+	Time          float64 `json:"time"`
+	Cte           float64 `json:"cte"`
+}
+
+/* Json msg used to control cars. MsgType must be filled with "control" */
+type ControlMsg struct {
+	MsgType  string  `json:"msg_type"`
+	Steering float32 `json:"steering"`
+	Throttle float32 `json:"throttle"`
+	Brake    float32 `json:"brake"`
+}