NOISSUE - Fix CoAP adapter (absmach#1572)

* Revert "NOISSUE - Add nats wrapper for COAP (absmach#1569)"

This reverts commit cc5d519.

Signed-off-by: dusanb94 <dusan.borovcanin@mainflux.com>

* Fix CoAP adapter

Signed-off-by: dusanb94 <dusan.borovcanin@mainflux.com>

* Update CoAP observation cancel

Signed-off-by: dusanb94 <dusan.borovcanin@mainflux.com>

* Fix observe

Signed-off-by: dusanb94 <dusan.borovcanin@mainflux.com>

* Fix GET handling

Signed-off-by: dusanb94 <dusan.borovcanin@mainflux.com>

* Revert authorization

Signed-off-by: dusanb94 <dusan.borovcanin@mainflux.com>

* Use constants instead of magic numbers

Signed-off-by: dusanb94 <dusan.borovcanin@mainflux.com>

* Remove an empty line

Signed-off-by: dusanb94 <dusan.borovcanin@mainflux.com>

* Extract special observe value to constant

Signed-off-by: dusanb94 <dusan.borovcanin@mainflux.com>

cmd/coap/main.go

@@ -20,8 +20,8 @@ import (
 	"github.com/mainflux/mainflux/coap"
 	"github.com/mainflux/mainflux/coap/api"
 	logger "github.com/mainflux/mainflux/logger"
-	"github.com/mainflux/mainflux/pkg/messaging/nats"
 	thingsapi "github.com/mainflux/mainflux/things/api/auth/grpc"
+	broker "github.com/nats-io/nats.go"
 	opentracing "github.com/opentracing/opentracing-go"
 	gocoap "github.com/plgd-dev/go-coap/v2"
 	stdprometheus "github.com/prometheus/client_golang/prometheus"
@@ -77,14 +77,13 @@ func main() {
 
 	tc := thingsapi.NewClient(conn, thingsTracer, cfg.thingsAuthTimeout)
 
-	pubsub, err := nats.NewPubSub(cfg.natsURL, "coap", logger)
+	nc, err := broker.Connect(cfg.natsURL)
 	if err != nil {
 		log.Fatalf(err.Error())
 	}
+	defer nc.Close()
 
-	defer pubsub.Close()
-
-	svc := coap.New(tc, pubsub)
+	svc := coap.New(tc, nc)
 
 	svc = api.LoggingMiddleware(svc, logger)
 

coap/adapter.go

@@ -11,8 +11,9 @@ import (
 	"fmt"
 	"sync"
 
+	"github.com/gogo/protobuf/proto"
 	"github.com/mainflux/mainflux/pkg/errors"
-	"github.com/mainflux/mainflux/pkg/messaging/nats"
+	broker "github.com/nats-io/nats.go"
 
 	"github.com/mainflux/mainflux"
 	"github.com/mainflux/mainflux/pkg/messaging"
@@ -41,16 +42,16 @@ var _ Service = (*adapterService)(nil)
 // Observers is a map of maps,
 type adapterService struct {
 	auth      mainflux.ThingsServiceClient
-	pubsub    nats.PubSub
+	conn      *broker.Conn
 	observers map[string]observers
 	obsLock   sync.Mutex
 }
 
 // New instantiates the CoAP adapter implementation.
-func New(auth mainflux.ThingsServiceClient, pubsub nats.PubSub) Service {
+func New(auth mainflux.ThingsServiceClient, nc *broker.Conn) Service {
 	as := &adapterService{
 		auth:      auth,
-		pubsub:    pubsub,
+		conn:      nc,
 		observers: make(map[string]observers),
 		obsLock:   sync.Mutex{},
 	}
@@ -69,7 +70,17 @@ func (svc *adapterService) Publish(ctx context.Context, key string, msg messagin
 	}
 	msg.Publisher = thid.GetValue()
 
-	return svc.pubsub.Publish(msg.Channel, msg)
+	data, err := proto.Marshal(&msg)
+	if err != nil {
+		return err
+	}
+
+	subject := fmt.Sprintf("%s.%s", chansPrefix, msg.Channel)
+	if msg.Subtopic != "" {
+		subject = fmt.Sprintf("%s.%s", subject, msg.Subtopic)
+	}
+
+	return svc.conn.Publish(subject, data)
 }
 
 func (svc *adapterService) Subscribe(ctx context.Context, key, chanID, subtopic string, c Client) error {
@@ -86,12 +97,7 @@ func (svc *adapterService) Subscribe(ctx context.Context, key, chanID, subtopic
 		subject = fmt.Sprintf("%s.%s", subject, subtopic)
 	}
 
-	go func() {
-		<-c.Done()
-		svc.remove(subject, c.Token())
-	}()
-
-	obs, err := NewObserver(subject, c, svc.pubsub)
+	obs, err := NewObserver(subject, c, svc.conn)
 	if err != nil {
 		c.Cancel()
 		return err
@@ -128,7 +134,7 @@ func (svc *adapterService) put(topic, token string, o Observer) error {
 	}
 	// If observer exists, cancel subscription and replace it.
 	if sub, ok := obs[token]; ok {
-		if err := sub.Cancel(topic); err != nil {
+		if err := sub.Cancel(); err != nil {
 			return errors.Wrap(ErrUnsubscribe, err)
 		}
 	}
@@ -139,13 +145,12 @@ func (svc *adapterService) put(topic, token string, o Observer) error {
 func (svc *adapterService) remove(topic, token string) error {
 	svc.obsLock.Lock()
 	defer svc.obsLock.Unlock()
-
 	obs, ok := svc.observers[topic]
 	if !ok {
 		return nil
 	}
 	if current, ok := obs[token]; ok {
-		if err := current.Cancel(topic); err != nil {
+		if err := current.Cancel(); err != nil {
 			return errors.Wrap(ErrUnsubscribe, err)
 		}
 	}

coap/api/logging.go

@@ -61,11 +61,20 @@ func (lm *loggingMiddleware) Subscribe(ctx context.Context, key, chanID, subtopi
 	return lm.svc.Subscribe(ctx, key, chanID, subtopic, c)
 }
 
-func (lm *loggingMiddleware) Unsubscribe(ctx context.Context, key, chanID, subtopic, token string) error {
+func (lm *loggingMiddleware) Unsubscribe(ctx context.Context, key, chanID, subtopic, token string) (err error) {
 	defer func(begin time.Time) {
-		message := fmt.Sprintf("Method unsubscribe for the client %s from the channel %s and subtopic %s took %s to complete without errors.", token, chanID, subtopic, time.Since(begin))
-		lm.logger.Info(fmt.Sprintf(message))
+		destChannel := chanID
+		if subtopic != "" {
+			destChannel = fmt.Sprintf("%s.%s", destChannel, subtopic)
+		}
+		message := fmt.Sprintf("Method unsubscribe for the client %s from the channel %s took %s to complete", token, destChannel, time.Since(begin))
+		if err != nil {
+			lm.logger.Warn(fmt.Sprintf("%s with error: %s.", message, err))
+			return
+		}
+		lm.logger.Info(fmt.Sprintf("%s without errors.", message))
 	}(time.Now())
 
 	return lm.svc.Unsubscribe(ctx, key, chanID, subtopic, token)
+
 }

coap/api/transport.go

@@ -27,13 +27,22 @@ import (
 )
 
 const (
-	protocol  = "coap"
-	authQuery = "auth"
+	protocol     = "coap"
+	authQuery    = "auth"
+	startObserve = 0 // observe option value that indicates start of observation
 )
 
-var channelPartRegExp = regexp.MustCompile(`^channels/([\w\-]+)/messages(/[^?]*)?(\?.*)?$`)
+var channelPartRegExp = regexp.MustCompile(`^/channels/([\w\-]+)/messages(/[^?]*)?(\?.*)?$`)
 
-var errMalformedSubtopic = errors.New("malformed subtopic")
+const (
+	numGroups    = 3 // entire expression + channel group + subtopic group
+	channelGroup = 2 // channel group is second in channel regexp
+)
+
+var (
+	errMalformedSubtopic = errors.New("malformed subtopic")
+	errBadOptions        = errors.New("bad options")
+)
 
 var (
 	logger  log.Logger
@@ -70,73 +79,79 @@ func handler(w mux.ResponseWriter, m *mux.Message) {
 		Context: m.Context,
 		Options: make(message.Options, 0, 16),
 	}
-	defer sendResp(w, &resp)
-	if m.Options == nil {
-		logger.Warn("Nil options")
-		resp.Code = codes.BadOption
-		return
-	}
+
 	msg, err := decodeMessage(m)
 	if err != nil {
 		logger.Warn(fmt.Sprintf("Error decoding message: %s", err))
 		resp.Code = codes.BadRequest
+		sendResp(w, &resp)
 		return
 	}
 	key, err := parseKey(m)
 	if err != nil {
 		logger.Warn(fmt.Sprintf("Error parsing auth: %s", err))
 		resp.Code = codes.Unauthorized
+		sendResp(w, &resp)
 		return
 	}
 	switch m.Code {
 	case codes.GET:
-		var obs uint32
-		obs, err = m.Options.Observe()
-		if err != nil {
-			resp.Code = codes.BadOption
-			logger.Warn(fmt.Sprintf("Error reading observe option: %s", err))
-			return
-		}
-		if obs == 0 {
-			c := coap.NewClient(w.Client(), m.Token, logger)
-			err = service.Subscribe(context.Background(), key, msg.Channel, msg.Subtopic, c)
-			break
-		}
-		service.Unsubscribe(context.Background(), key, msg.Channel, msg.Subtopic, m.Token.String())
+		err = handleGet(m, w.Client(), msg, key)
 	case codes.POST:
 		err = service.Publish(context.Background(), key, msg)
 	default:
-		resp.Code = codes.NotFound
-		return
+		err = errors.ErrNotFound
 	}
 	if err != nil {
 		switch {
-		case errors.Contains(err, errors.ErrAuthorization):
+		case err == errBadOptions:
+			resp.Code = codes.BadOption
+		case err == errors.ErrNotFound:
+			resp.Code = codes.NotFound
+		case errors.Contains(err, errors.ErrAuthorization),
+			errors.Contains(err, errors.ErrAuthentication):
 			resp.Code = codes.Unauthorized
-			return
-		case errors.Contains(err, coap.ErrUnsubscribe):
+		default:
 			resp.Code = codes.InternalServerError
 		}
+		sendResp(w, &resp)
+	}
+}
+
+func handleGet(m *mux.Message, c mux.Client, msg messaging.Message, key string) error {
+	var obs uint32
+	obs, err := m.Options.Observe()
+	if err != nil {
+		logger.Warn(fmt.Sprintf("Error reading observe option: %s", err))
+		return errBadOptions
 	}
+	if obs == startObserve {
+		c := coap.NewClient(c, m.Token, logger)
+		return service.Subscribe(context.Background(), key, msg.Channel, msg.Subtopic, c)
+	}
+	return service.Unsubscribe(context.Background(), key, msg.Channel, msg.Subtopic, m.Token.String())
 }
 
 func decodeMessage(msg *mux.Message) (messaging.Message, error) {
+	if msg.Options == nil {
+		return messaging.Message{}, errBadOptions
+	}
 	path, err := msg.Options.Path()
 	if err != nil {
 		return messaging.Message{}, err
 	}
 	channelParts := channelPartRegExp.FindStringSubmatch(path)
-	if len(channelParts) < 2 {
+	if len(channelParts) < numGroups {
 		return messaging.Message{}, errMalformedSubtopic
 	}
 
-	st, err := parseSubtopic(channelParts[2])
+	st, err := parseSubtopic(channelParts[channelGroup])
 	if err != nil {
 		return messaging.Message{}, err
 	}
 	ret := messaging.Message{
 		Protocol: protocol,
-		Channel:  parseID(path),
+		Channel:  channelParts[1],
 		Subtopic: st,
 		Payload:  []byte{},
 		Created:  time.Now().UnixNano(),
@@ -152,15 +167,10 @@ func decodeMessage(msg *mux.Message) (messaging.Message, error) {
 	return ret, nil
 }
 
-func parseID(path string) string {
-	vars := strings.Split(path, "/")
-	if len(vars) > 1 {
-		return vars[1]
-	}
-	return ""
-}
-
 func parseKey(msg *mux.Message) (string, error) {
+	if obs, _ := msg.Options.Observe(); obs != 0 && msg.Code == codes.GET {
+		return "", nil
+	}
 	authKey, err := msg.Options.GetString(message.URIQuery)
 	if err != nil {
 		return "", err

coap/client.go

@@ -5,7 +5,9 @@ package coap
 
 import (
 	"bytes"
+	"context"
 	"fmt"
+	"sync/atomic"
 
 	"github.com/mainflux/mainflux/logger"
 	"github.com/mainflux/mainflux/pkg/errors"
@@ -30,25 +32,36 @@ type observers map[string]Observer
 var ErrOption = errors.New("unable to set option")
 
 type client struct {
-	client mux.Client
-	token  message.Token
-	logger logger.Logger
+	client  mux.Client
+	token   message.Token
+	observe uint32
+	logger  logger.Logger
 }
 
 // NewClient instantiates a new Observer.
-func NewClient(mc mux.Client, token message.Token, l logger.Logger) Client {
+func NewClient(c mux.Client, tkn message.Token, l logger.Logger) Client {
 	return &client{
-		client: mc,
-		token:  token,
-		logger: l,
+		client:  c,
+		token:   tkn,
+		logger:  l,
+		observe: 0,
 	}
 }
 
 func (c *client) Done() <-chan struct{} {
-	return c.client.Context().Done()
+	return c.client.Done()
 }
 
 func (c *client) Cancel() error {
+	m := message.Message{
+		Code:    codes.Content,
+		Token:   c.token,
+		Context: context.Background(),
+		Options: make(message.Options, 0, 16),
+	}
+	if err := c.client.WriteMessage(&m); err != nil {
+		c.logger.Error(fmt.Sprintf("Error sending message: %s.", err))
+	}
 	return c.client.Close()
 }
 
@@ -63,22 +76,29 @@ func (c *client) SendMessage(msg messaging.Message) error {
 		Context: c.client.Context(),
 		Body:    bytes.NewReader(msg.Payload),
 	}
+
+	atomic.AddUint32(&c.observe, 1)
 	var opts message.Options
 	var buff []byte
-
 	opts, n, err := opts.SetContentFormat(buff, message.TextPlain)
 	if err == message.ErrTooSmall {
 		buff = append(buff, make([]byte, n)...)
-		opts, n, err = opts.SetContentFormat(buff, message.TextPlain)
+		_, _, err = opts.SetContentFormat(buff, message.TextPlain)
 	}
 	if err != nil {
 		c.logger.Error(fmt.Sprintf("Can't set content format: %s.", err))
 		return errors.Wrap(ErrOption, err)
 	}
-	m.Options = opts
-	if err := c.client.WriteMessage(&m); err != nil {
-		c.logger.Error(fmt.Sprintf("Error sending message: %s.", err))
-		return err
+	opts = append(opts, message.Option{ID: message.Observe, Value: []byte{byte(c.observe)}})
+	opts, n, err = opts.SetObserve(buff, uint32(c.observe))
+	if err == message.ErrTooSmall {
+		buff = append(buff, make([]byte, n)...)
+		opts, _, err = opts.SetObserve(buff, uint32(c.observe))
 	}
-	return nil
+	if err != nil {
+		return fmt.Errorf("cannot set options to response: %w", err)
+	}
+
+	m.Options = opts
+	return c.client.WriteMessage(&m)
 }