Go语言在CentOS上如何实现消息队列

在CentOS上使用Go语言实现消息队列，你可以选择多种消息队列系统，比如RabbitMQ、Kafka、NATS等。以下是使用RabbitMQ作为消息队列系统的一个基本示例。

步骤 1: 安装RabbitMQ

首先，你需要在CentOS上安装RabbitMQ服务器。

1. 添加Erlang仓库并安装Erlang：

sudo yum install -y epel-release
sudo yum install -y erlang

2. 添加RabbitMQ仓库：

echo "[rabbitmq-server]
name=rabbitmq-server
baseurl=https://packagecloud.io/rabbitmq/rabbitmq-server/el/7/$basearch
repo_gpgcheck=1
gpgcheck=1
enabled=1
gpgkey=https://packagecloud.io/rabbitmq/rabbitmq-server/gpgkey" | sudo tee /etc/yum.repos.d/rabbitmq.repo

3. 安装RabbitMQ服务器：

sudo yum install -y rabbitmq-server

4. 启动并启用RabbitMQ服务：

sudo systemctl start rabbitmq-server
sudo systemctl enable rabbitmq-server

5. 创建一个RabbitMQ用户并设置权限（可选）：

sudo rabbitmqctl add_user your_username your_password
sudo rabbitmqctl set_permissions -p / your_username ".*" ".*" ".*"
sudo rabbitmqctl set_user_tags your_username administrator

步骤 2: 在Go中使用RabbitMQ

安装Go的RabbitMQ客户端库，比如streadway/amqp：

go get github.com/streadway/amqp

编写Go代码来发送和接收消息：

发送消息 (sender.go)

package main

import (
	"fmt"
	"log"

	"github.com/streadway/amqp"
)

func failOnError(err error, msg string) {
	if err != nil {
		log.Fatalf("%s: %s", msg, err)
	}
}

func main() {
	conn, err := amqp.Dial("amqp://your_username:your_password@localhost:5672/")
	failOnError(err, "Failed to connect to RabbitMQ")
	defer conn.Close()

	ch, err := conn.Channel()
	failOnError(err, "Failed to open a channel")
	defer ch.Close()

	q, err := ch.QueueDeclare(
		"hello", // name
		false,   // durable
		false,   // delete when unused
		false,   // exclusive
		false,   // no-wait
		nil,     // arguments
	)
	failOnError(err, "Failed to declare a queue")

	body := "Hello World!"
	err = ch.Publish(
		"",     // exchange
		q.Name, // routing key
		false,  // mandatory
		false,  // immediate
		amqp.Publishing{
			ContentType: "text/plain",
			Body:        []byte(body),
		})
	failOnError(err, "Failed to publish a message")
	fmt.Println(" [x] Sent %s", body)
}

接收消息 (receiver.go)

package main

import (
	"fmt"
	"log"

	"github.com/streadway/amqp"
)

func failOnError(err error, msg string) {
	if err != nil {
		log.Fatalf("%s: %s", msg, err)
	}
}

func main() {
	conn, err := amqp.Dial("amqp://your_username:your_password@localhost:5672/")
	failOnError(err, "Failed to connect to RabbitMQ")
	defer conn.Close()

	ch, err := conn.Channel()
	failOnError(err, "Failed to open a channel")
	defer ch.Close()

	q, err := ch.QueueDeclare(
		"hello", // name
		false,   // durable
		false,   // delete when unused
		false,   // exclusive
		false,   // no-wait
		nil,     // arguments
	)
	failOnError(err, "Failed to declare a queue")

	msgs, err := ch.Consume(
		q.Name, // queue
		"",     // consumer
		true,   // auto-ack
		false,  // exclusive
		false,  // no-local
		false,  // no-wait
		nil,    // args
	)
	failOnError(err, "Failed to register a consumer")

	forever := make(chan bool)

	go func() {
		for d := range msgs {
			fmt.Printf("Received a message: %s\n", d.Body)
		}
	}()

	fmt.Println(" [*] Waiting for messages. To exit press CTRL+C")
	<-forever
}

运行发送者和接收者程序：

go run sender.go
go run receiver.go

这样，你就有了一个基本的在CentOS上使用Go语言和RabbitMQ实现消息队列的例子。根据你的需求，你可以扩展这个例子，比如添加持久化队列、交换机、绑定等高级特性。