version 0.1.0

Author: afaf

.gitignore

@@ -0,0 +1,21 @@
+# If you prefer the allow list template instead of the deny list, see community template:
+# https://github.com/github/gitignore/blob/main/community/Golang/Go.AllowList.gitignore
+#
+# Binaries for programs and plugins
+*.exe
+*.exe~
+*.dll
+*.so
+*.dylib
+
+# Test binary, built with `go test -c`
+*.test
+
+# Output of the go coverage tool, specifically when used with LiteIDE
+*.out
+
+# Dependency directories (remove the comment below to include it)
+# vendor/
+
+# Go workspace file
+# go.work

LICENSE.md

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+MIT License
+
+Copyright (c) 2021 Lane Wagner
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

README.md

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+# Go RabbitMQ Auto-Reconnect Project
+
+This project demonstrates a simple implementation of a RabbitMQ consumer and producer in Go with automatic reconnection capabilities.
+
+Explores the hypothesis of using a single connection for many channels, both for producers and consumers, in a RabbitMQ setup. This architectural choice aims to optimize resource usage and improve performance in scenarios with a large number of channels.
+
+
+## Requirements
+- go 1.21
+- docker
+
+### Installation
+
+1. use the module:
+```bash
+   go get github.com/afaf-tech/go-rabbitmq 
+```
+#### Consumer 
+```bash
+# How to use the consumer
+```
+
+
+#### Producer
+```bash
+# How to use the producer
+```
+
+
+## Backlog
+- Proper Logging
+- Producer function
+
+
+## License
+This project is licensed under the MIT License - see the LICENSE.md file for details.

consumer.go

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+package rabbitmq
+
+import (
+	"context"
+	"log"
+	"time"
+
+	amqp "github.com/rabbitmq/amqp091-go"
+)
+
+type Consumer struct {
+	conn        *Connection
+	channel     *amqp.Channel
+	queueName   string
+	name        string
+	queueConfig QueueOptions
+}
+
+// NewConsumer initializes a new Consumer instance and declares the queue with the specified options
+func NewConsumer(conn *Connection, name, queue string, options QueueOptions) (*Consumer, error) {
+	ch, err := conn.OpenChannel()
+	if err != nil {
+		log.Printf("[%s] Failed to open a channel", name)
+		return nil, err
+	}
+
+	// Declare the queue
+	_, err = ch.QueueDeclare(
+		queue,
+		options.Durable,
+		options.AutoDelete,
+		options.Exclusive,
+		options.NoWait,
+		options.Args,
+	)
+	if err != nil {
+		log.Printf("[%s] Failed to declare queue: %v", name, err)
+		defer ch.Close()
+		return nil, err
+	}
+
+	return &Consumer{
+		conn:        conn,
+		channel:     ch,
+		queueName:   queue,
+		name:        name,
+		queueConfig: options,
+	}, nil
+}
+
+// Start begins the consumer's main loop
+func (c *Consumer) Start(ctx context.Context, fn func(*Connection, string, string, *<-chan amqp.Delivery)) {
+	var err error
+
+	for {
+		// Ensure connection and channel are valid before starting consumption
+		err = c.checkConnectionAndChannel()
+		if err != nil {
+			time.Sleep(c.conn.config.RetryDuration)
+			continue
+		}
+
+		// Register the consumer and handle any errors
+		msgs, err := c.channel.ConsumeWithContext(
+			ctx,
+			c.queueName, // queue
+			c.name,      // consumer
+			false,       // auto-ack
+			false,       // exclusive
+			false,       // no-local
+			false,       // no-wait
+			nil,         // args
+		)
+		if err != nil {
+			log.Printf("[%s] Failed to register a consumer: %v. Retrying in 5 seconds.", c.name, err)
+			time.Sleep(c.conn.config.RetryDuration)
+			continue
+		}
+
+		// Execute the user-defined function
+		fn(c.conn, c.name, c.queueName, &msgs)
+
+		// Close the channel after consuming messages (if necessary)
+		if c.channel != nil {
+			c.channel.Close()
+		}
+	}
+}
+
+// checkConnectionAndChannel ensures that both the connection and channel are open
+func (c *Consumer) checkConnectionAndChannel() error {
+	var err error
+	// Check if the connection is closed
+	if c.conn.IsClosed() {
+		log.Printf("[%s] Connection is closed. Attempting to reconnect...", c.name)
+		err = c.conn.Reconnect()
+		if err != nil {
+			log.Printf("[%s] Failed to reconnect: %v. Retrying in 5 seconds.", c.name, err)
+			return err
+		}
+		log.Printf("[%s] Reconnected to RabbitMQ", c.name)
+	}
+
+	// Check if the channel is closed or nil
+	if c.channel == nil || c.channel.IsClosed() {
+		log.Printf("[%s] Channel is nil or closed. Trying to reopen...", c.name)
+		c.channel, err = c.conn.OpenChannel()
+		if err != nil {
+			log.Printf("[%s] Failed to reopen channel: %v. Retrying in 5 seconds.", c.name, err)
+			return err
+		}
+		log.Printf("[%s] Channel reopened", c.name)
+	}
+
+	return nil
+}

go.mod

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+module github.com/afaf-tech/go-rabbitmq
+
+go 1.22.1
+
+require github.com/rabbitmq/amqp091-go v1.10.0

go.sum

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+github.com/rabbitmq/amqp091-go v1.10.0 h1:STpn5XsHlHGcecLmMFCtg7mqq0RnD+zFr4uzukfVhBw=
+github.com/rabbitmq/amqp091-go v1.10.0/go.mod h1:Hy4jKW5kQART1u+JkDTF9YYOQUHXqMuhrgxOEeS7G4o=
+go.uber.org/goleak v1.3.0 h1:2K3zAYmnTNqV73imy9J1T3WC+gmCePx2hEGkimedGto=
+go.uber.org/goleak v1.3.0/go.mod h1:CoHD4mav9JJNrW/WLlf7HGZPjdw8EucARQHekz1X6bE=

producer.go

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+package rabbitmq
+
+import (
+	"context"
+	"log"
+	"time"
+
+	amqp "github.com/rabbitmq/amqp091-go"
+)
+
+type Producer struct {
+	conn      *Connection
+	channel   *amqp.Channel
+	queueName string
+	name      string
+}
+
+// NewProducer initializes a new Producer instance and declares the queue with the specified options
+func NewProducer(conn *Connection, name, queue string) (*Producer, error) {
+	// Ensure the connection is established
+	if conn.IsClosed() {
+		err := conn.Connect()
+		if err != nil {
+			log.Printf("[%s] Failed to connect to RabbitMQ", name)
+			return nil, err
+		}
+	}
+
+	ch, err := conn.OpenChannel()
+	if err != nil {
+		log.Printf("[%s] Failed to open a channel", name)
+		return nil, err
+	}
+
+	return &Producer{
+		conn:      conn,
+		channel:   ch,
+		queueName: queue,
+		name:      name,
+	}, nil
+}
+
+type PublishOptions struct {
+	Exchange    string     // The exchange to publish the message to
+	RoutingKey  string     // The routing key to use for the message
+	ContentType string     // The content type of the message (e.g., "text/plain")
+	Body        []byte     // The actual message body
+	Mandatory   bool       // Whether the message is mandatory
+	Immediate   bool       // Whether the message is immediate
+	Headers     amqp.Table // Optional headers for the message
+}
+
+// Publish sends a message to the queue with retry logic and context support
+func (p *Producer) Publish(ctx context.Context, message []byte, options PublishOptions) error {
+	if ctx == nil {
+		// Default to a background context with a timeout
+		defaultCtx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+		defer cancel()
+		ctx = defaultCtx
+	}
+
+	retryDuration := p.conn.config.RetryDuration
+
+	// Retry indefinitely until the message is successfully published
+	for {
+		// Check if connection or channel is closed, attempt to reconnect if necessary
+		err := p.checkConnection()
+		if err != nil {
+			time.Sleep(retryDuration)
+			continue
+		}
+
+		// Attempt to publish the message
+		err = p.channel.PublishWithContext(
+			ctx,
+			options.Exchange,   // Use the exchange from the options
+			options.RoutingKey, // Use the routing key from the options
+			options.Mandatory,  // Use the mandatory flag from the options
+			options.Immediate,  // Use the immediate flag from the options
+			amqp.Publishing{
+				ContentType: options.ContentType, // Use the content type from the options
+				Body:        options.Body,        // Use the message body from the options
+				Headers:     options.Headers,     // Use the headers from the options (if any)
+			},
+		)
+
+		if err == nil {
+			return nil
+		}
+
+		log.Printf("[%s] Failed to publish message: %v. Retrying in %v...", p.name, err, retryDuration)
+		time.Sleep(retryDuration)
+	}
+}
+
+// checkConnection checks if the connection and channel are valid and reconnects if necessary
+func (p *Producer) checkConnection() error {
+	// If the connection is closed, try to reconnect
+	if p.conn.IsClosed() {
+		log.Printf("[%s] Connection is closed. Attempting to reconnect...", p.name)
+		err := p.conn.Reconnect()
+		if err != nil {
+			log.Printf("[%s] Failed to reconnect: %v. Retrying...", p.name, err)
+			return err
+		}
+		log.Printf("[%s] Reconnected to RabbitMQ", p.name)
+	}
+
+	// If the channel is closed or nil, try to open a new one
+	if p.channel == nil || p.channel.IsClosed() {
+		log.Printf("[%s] Channel is closed or nil. Reopening channel...", p.name)
+		ch, err := p.conn.OpenChannel()
+		if err != nil {
+			log.Printf("[%s] Failed to open channel: %v. Retrying...", p.name, err)
+			return err
+		}
+		p.channel = ch
+		log.Printf("[%s] Channel reopened", p.name)
+	}
+
+	return nil
+}
+
+// Close gracefully shuts down the producer
+func (p *Producer) Close() {
+	if p.channel != nil {
+		p.channel.Close()
+	}
+	if p.conn != nil {
+		p.conn.Close()
+	}
+}