From 4d54df7868f3a431642a6b9acd695501927a51ad Mon Sep 17 00:00:00 2001
From: skrater <skrater@gmail.com>
Date: Fri, 15 Mar 2019 11:27:45 -0300
Subject: [PATCH] Fix producer to no block when publish fail

---
 amqp/producer.go | 91 ++++++++++++++++++++++++------------------------
 1 file changed, 46 insertions(+), 45 deletions(-)

diff --git a/amqp/producer.go b/amqp/producer.go
index 0cb10e0..7e8a6d1 100644
--- a/amqp/producer.go
+++ b/amqp/producer.go
@@ -23,14 +23,13 @@ type message struct {
 
 // producer holds a amqp connection and channel to publish messages to.
 type producer struct {
-	m                sync.Mutex
-	wg               sync.WaitGroup
-	conn             *connection
-	channel          *amqplib.Channel
-	notifyConfirm    chan amqplib.Confirmation
-	connectionClosed <-chan error
-	closeQueue       chan bool
-	config           ProducerConfig
+	m             sync.Mutex
+	wg            sync.WaitGroup
+	conn          *connection
+	channel       *amqplib.Channel
+	notifyConfirm chan amqplib.Confirmation
+	closeQueue    chan bool
+	config        ProducerConfig
 
 	internalQueue chan message
 
@@ -55,16 +54,13 @@ func NewProducer(c messaging.Connection, exchange string) (*producer, error) {
 
 // NewProducerConfig returns a new AMQP Producer.
 func NewProducerConfig(c messaging.Connection, exchange string, config ProducerConfig) (*producer, error) {
-	conn := c.(*connection)
-
 	producer := &producer{
-		conn:             c.(*connection),
-		config:           config,
-		internalQueue:    make(chan message, 2),
-		exchangeName:     exchange,
-		notifyConfirm:    make(chan amqplib.Confirmation),
-		closeQueue:       make(chan bool),
-		connectionClosed: conn.NotifyConnectionClose(),
+		conn:          c.(*connection),
+		config:        config,
+		internalQueue: make(chan message, 2),
+		exchangeName:  exchange,
+		notifyConfirm: make(chan amqplib.Confirmation),
+		closeQueue:    make(chan bool),
 	}
 
 	err := producer.setupTopology()
@@ -73,6 +69,7 @@ func NewProducerConfig(c messaging.Connection, exchange string, config ProducerC
 		return nil, err
 	}
 
+	go producer.drainInternalQueue()
 	go producer.handleReestablishedConnnection()
 
 	return producer, err
@@ -134,6 +131,10 @@ func (p *producer) Close() {
 	close(p.closeQueue)
 
 	p.channel.Close()
+
+	for _, c := range p.closes {
+		c <- true
+	}
 }
 
 // changeChannel takes a new channel to the queue,
@@ -191,9 +192,7 @@ func (p *producer) setupTopology() error {
 	log.WithFields(log.Fields{
 		"type":     "goevents",
 		"sub_type": "producer",
-	}).Debug("Topology ready. Draining internal queue.")
-
-	go p.drainInternalQueue()
+	}).Debug("Topology ready.")
 
 	return nil
 }
@@ -217,6 +216,11 @@ func (p *producer) handleReestablishedConnnection() {
 }
 
 func (p *producer) publishMessage(msg amqplib.Publishing, queue string) (err error) {
+	if !p.conn.IsConnected() {
+		err = errors.New("connection is not open")
+		return
+	}
+
 	log.WithFields(log.Fields{
 		"action":     queue,
 		"body":       msg.Body,
@@ -241,11 +245,6 @@ func (p *producer) publishMessage(msg amqplib.Publishing, queue string) (err err
 		}
 	}()
 
-	if !p.conn.IsConnected() {
-		err = errors.New("connection is not open")
-		return
-	}
-
 	err = p.channel.Publish(p.exchangeName, queue, false, false, msg)
 
 	if err != nil {
@@ -257,6 +256,9 @@ func (p *producer) publishMessage(msg amqplib.Publishing, queue string) (err err
 		if confirm.Ack {
 			return
 		}
+
+		err = ErrNotAcked
+		return
 	case <-time.After(p.config.publishInterval):
 		err = ErrNotAcked
 		return
@@ -277,30 +279,29 @@ func (p *producer) drainInternalQueue() {
 		select {
 		case <-p.closeQueue:
 			return
-		case <-p.connectionClosed:
-			return
 		case m := <-p.internalQueue:
-			// block until confirmation
-			err := p.publishMessage(m.msg, m.action)
+			retry := true
 
-			if err != nil {
-				log.WithFields(log.Fields{
-					"action":     m.action,
-					"body":       m.msg.Body,
-					"message_id": m.msg.MessageId,
-					"error":      err,
-					"type":       "goevents",
-					"sub_type":   "producer",
-				}).Error("Error publishing message to the exchange. Retrying...")
+			for retry {
+				// block until confirmation
+				err := p.publishMessage(m.msg, m.action)
 
-				p.internalQueue <- m
-			} else {
-				p.wg.Done()
+				if err != nil {
+					log.WithFields(log.Fields{
+						"action":     m.action,
+						"body":       m.msg.Body,
+						"message_id": m.msg.MessageId,
+						"error":      err,
+						"type":       "goevents",
+						"sub_type":   "producer",
+					}).Error("Error publishing message to the exchange. Retrying...")
+
+					time.Sleep(p.config.publishInterval)
+				} else {
+					p.wg.Done()
+					retry = false
+				}
 			}
 		}
 	}
-
-	for _, c := range p.closes {
-		c <- true
-	}
 }