mqtt 服务器/客户端搭建实例
Mqtt最开始是为石油管道的监控而设计的一个协议，占用带宽小，低功耗。在iot领域有广泛应用。
- 服务端用erlang编写的一个开源项目：emqqtd
- 客户端用golang客户端的库：“github.com/eclipse/paho.mqtt.golang”
服务器端搭建：
下载预编译安装包：
root@ubuntu:/home/jack# wget https://github.com/emqx/emqx/releases/download/v4.0.4/emqx-ubuntu18.04-v4.0.4.zip
--2020-04-18 18:54:51-- https://github.com/emqx/emqx/releases/download/v4.0.4/emqx-ubuntu18.04-v4.0.4.zip
Resolving github.com (github.com)... 52.74.223.119
Connecting to github.com (github.com)|52.74.223.119|:443... connected.
HTTP request sent, awaiting response... 302 Found
Location: https://github-production-release-asset-2e65be.s3.amazonaws.com/7202769/4b404580-5fa4-11ea-9fe4-73ad70b12bdc?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=AKIAIWNJYAX4CSVEH53A%2F20200419%2Fus-east-1%2Fs3%2Faws4_request&X-Amz-Date=20200419T015452Z&X-Amz-Expires=300&X-Amz-Signature=6f5336e167fccc50b81ab189f5e3f8edfd1ccf4daa862af3a5d564a4cc17893b&X-Amz-SignedHeaders=host&actor_id=0&repo_id=7202769&response-content-disposition=attachment%3B%20filename%3Demqx-ubuntu18.04-v4.0.4.zip&response-content-type=application%2Foctet-stream [following]
--2020-04-18 18:54:52-- https://github-production-release-asset-2e65be.s3.amazonaws.com/7202769/4b404580-5fa4-11ea-9fe4-73ad70b12bdc?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=AKIAIWNJYAX4CSVEH53A%2F20200419%2Fus-east-1%2Fs3%2Faws4_request&X-Amz-Date=20200419T015452Z&X-Amz-Expires=300&X-Amz-Signature=6f5336e167fccc50b81ab189f5e3f8edfd1ccf4daa862af3a5d564a4cc17893b&X-Amz-SignedHeaders=host&actor_id=0&repo_id=7202769&response-content-disposition=attachment%3B%20filename%3Demqx-ubuntu18.04-v4.0.4.zip&response-content-type=application%2Foctet-stream
Resolving github-production-release-asset-2e65be.s3.amazonaws.com (github-production-release-asset-2e65be.s3.amazonaws.com)... 52.217.46.76
Connecting to github-production-release-asset-2e65be.s3.amazonaws.com (github-production-release-asset-2e65be.s3.amazonaws.com)|52.217.46.76|:443... connected.
HTTP request sent, awaiting response... 200 OK
Length: 23267163 (22M) [application/octet-stream]
Saving to: ‘emqx-ubuntu18.04-v4.0.4.zip’
emqx-ubuntu18.04-v4.0.4.zip 100%[=================================================================================>] 22.19M 1.45MB/s in 16s
2020-04-18 18:55:10 (1.36 MB/s) - ‘emqx-ubuntu18.04-v4.0.4.zip’ saved [23267163/23267163]
root@ubuntu:/home/jack
解压，查看目录结构：
root@ubuntu:/home/jack# unzip emqx-ubuntu18.04-v4.0.4.zip
root@ubuntu:/home/jack/mqttd/emqx# tree -L 1
.
├── bin
├── data
├── erts-10.5.2
├── etc
├── lib
├── log
└── releases
7 directories, 0 files
root@ubuntu:/home/jack/mqttd/emqx#
启动服务器:
root@ubuntu:/home/jack/mqttd/emqx# ./bin/emqx start
EMQ X Broker v4.0.4 is started successfully!
root@ubuntu:/home/jack/mqttd/emqx#
查看状态：
root@ubuntu:/home/jack/mqttd/emqx# ./bin/emqx_ctl status
Node '[email protected]' is started
emqx 4.0.4 is running
root@ubuntu:/home/jack/mqttd/emqx#
停止服务器：
root@ubuntu:/home/jack/mqttd/emqx# ./bin/emqx stop
ok
root@ubuntu:/home/jack/mqttd/emqx#
mqtt服务器的ip查看：
root@ubuntu:/home/jack/mqttd/emqx# ifconfig
ens33: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 192.168.1.243 netmask 255.255.255.0 broadcast 192.168.1.255
inet6 fe80::20c:29ff:fef4:a0f6 prefixlen 64 scopeid 0x20<link>
ether 00:0c:29:f4:a0:f6 txqueuelen 1000 (Ethernet)
RX packets 193799 bytes 60667948 (60.6 MB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 140410 bytes 12827731 (12.8 MB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
lo: flags=73<UP,LOOPBACK,RUNNING> mtu 65536
inet 127.0.0.1 netmask 255.0.0.0
inet6 ::1 prefixlen 128 scopeid 0x10<host>
loop txqueuelen 1000 (Local Loopback)
RX packets 1328 bytes 127242 (127.2 KB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 1328 bytes 127242 (127.2 KB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
root@ubuntu:/home/jack/mqttd/emqx#
服务器启动后，可以通过dash board来监控mqtt broker的状态
在浏览器输入：http://192.168.1.243:18083/#/clients，用户名为：admin，密码为：public。如下图：
vscode IDE，git。
注意：依赖的net包容易下载失败：go get golang.org/x/net/proxy，用git从github下载后，将包拷贝到D:\GOPATH\src\golang.org\x\net目录即可
mqtt客户端实现：
package main
import (
"fmt"
"log"
"os"
"time"
mqtt "github.com/eclipse/paho.mqtt.golang"
)
//创建全局mqtt publish消息处理 handler
var messagePubHandler mqtt.MessageHandler = func(client mqtt.Client, msg mqtt.Message) {
fmt.Println("发布消息：")
fmt.Printf("TOPIC: %s\n", msg.Topic())
fmt.Printf("MSG: %s\n", msg.Payload())
}
//创建全局mqtt sub消息处理 handler
var messageSubHandler mqtt.MessageHandler = func(client mqtt.Client, msg mqtt.Message) {
fmt.Println("收到订阅消息：")
fmt.Printf("Sub Client Topic : %s \n", msg.Topic())
fmt.Printf("Sub Client msg : %s \n", msg.Payload())
}
func main() {
mqtt.DEBUG = log.New(os.Stdout, "", 0)
mqtt.ERROR = log.New(os.Stdout, "", 0)
//opts := mqtt.NewClientOptions().AddBroker("tcp://broker.emqx.io:1883").SetClientID("emqx_test_client")
// 创建消息发布go程
go func() {
opts := mqtt.NewClientOptions().AddBroker("tcp://192.168.1.243:1883").SetClientID("emqx_test_client66666")
opts.SetKeepAlive(60 * time.Second)
// Message callback handler，在没有任何订阅时，发布端调用此函数
opts.SetDefaultPublishHandler(messagePubHandler)
opts.SetPingTimeout(1 * time.Second)
client := mqtt.NewClient(opts)
if token := client.Connect(); token.Wait() && token.Error() != nil {
panic(token.Error())
}
for i := 0; i < 6; i++ {
time.Sleep(1 * time.Second)
fmt.Println("发布一条天气预报消息")
token := client.Publish("testtopic/1", 0, false, "Hello World，深圳天气晴朗")
token.Wait()
}
fmt.Println("发布客户端断开与broker的连接")
client.Disconnect(250)
}()
// 创建消息订阅go程
go func() {
opts := mqtt.NewClientOptions().AddBroker("tcp://192.168.1.243:1883").SetClientID("emqx_test_client99999")
opts.SetKeepAlive(60 * time.Second)
opts.SetPingTimeout(1 * time.Second)
client := mqtt.NewClient(opts)
if token := client.Connect(); token.Wait() && token.Error() != nil {
panic(token.Error())
}
// Subscription
/*if token := client.Subscribe("testtopic/#", 0, messageSubHandler); token.Wait() && token.Error() != nil {
fmt.Println(token.Error())
os.Exit(1)
}*/
for i := 0; i < 6; i++ {
time.Sleep(time.Duration(3) * time.Second)
//发布消息
if token := client.Subscribe("testtopic/#", 1, messageSubHandler); token.Wait() && token.Error() != nil {
fmt.Println(token.Error())
os.Exit(1)
}
}
// Cancel subscription
if token := client.Unsubscribe("testtopic/#"); token.Wait() && token.Error() != nil {
fmt.Println(token.Error())
os.Exit(1)
}
fmt.Println("订阅客户端断开与broker的连接")
//c.Disconnect(250)
}()
// Disconnect
time.Sleep(10 * time.Second)
}
按F5，执行效果：
API server listening at: 127.0.0.1:34378
[client] Connect()
[client] Connect()
[store] memorystore initialized
[store] memorystore initialized
[client] about to write new connect msg
[client] about to write new connect msg
[client] socket connected to broker
[client] Using MQTT 3.1.1 protocol
[client] socket connected to broker
[client] Using MQTT 3.1.1 protocol
[net] connect started
[net] connect started
[net] received connack
[client] client is connected
[client] exit startClient
[pinger] keepalive starting
[net] logic started
[net] logic waiting for msg on ibound
[net] outgoing started
[net] outgoing waiting for an outbound message
[net] incoming started
[net] received connack
[pinger] keepalive starting
[client] client is connected
[client] exit startClient
[net] logic started
[net] logic waiting for msg on ibound
[net] outgoing started
[net] outgoing waiting for an outbound message
[net] incoming started
发布一条天气预报消息
[client] enter Publish
[client] sending publish message, topic: testtopic/1
[net] obound wrote msg, id: 0
[net] outgoing waiting for an outbound message
发布一条天气预报消息
[client] enter Publish
[client] sending publish message, topic: testtopic/1
[net] obound wrote msg, id: 0
[net] outgoing waiting for an outbound message
[client] enter Subscribe
[client] SUBSCRIBE: dup: false qos: 1 retain: false rLength: 0 MessageID: 1 topics: [testtopic/#]
[client] sending subscribe message, topic: testtopic/#
[client] exit Subscribe
[net] obound priority msg to write, type *packets.SubscribePacket
[net] outgoing waiting for an outbound message
[net] Received Message
[net] logic got msg on ibound
[store] memorystore del: message 1 was deleted
[net] received suback, id: 1
[net] granted qoss [1]
[net] logic waiting for msg on ibound
发布一条天气预报消息
[client] enter Publish
[client] sending publish message, topic: testtopic/1
[net] obound wrote msg, id: 0
[net] outgoing waiting for an outbound message
[net] Received Message
[net] logic got msg on ibound
[net] received publish, msgId: 0
[net] putting msg on onPubChan
[net] done putting msg on incomingPubChan
[net] logic waiting for msg on ibound
收到订阅消息：
Sub Client Topic : testtopic/1
Sub Client msg : Hello World，深圳天气晴朗2
发布一条天气预报消息
[client] enter Publish
[client] sending publish message, topic: testtopic/1
[net] obound wrote msg, id: 0
[net] outgoing waiting for an outbound message
[net] Received Message
[net] logic got msg on ibound
[net] received publish, msgId: 0
[net] putting msg on onPubChan
[net] done putting msg on incomingPubChan
[net] logic waiting for msg on ibound
收到订阅消息：
Sub Client Topic : testtopic/1
Sub Client msg : Hello World，深圳天气晴朗3
[pinger] ping check 1.9993801
[pinger] ping check 0.9978095
发布一条天气预报消息
[client] enter Publish
[client] sending publish message, topic: testtopic/1
[net] obound wrote msg, id: 0
[net] outgoing waiting for an outbound message
[net] Received Message
[net] logic got msg on ibound
[net] received publish, msgId: 0
[net] putting msg on onPubChan
[net] done putting msg on incomingPubChan
[net] logic waiting for msg on ibound
收到订阅消息：
Sub Client Topic : testtopic/1
Sub Client msg : Hello World，深圳天气晴朗4
[client] enter Subscribe
[client] SUBSCRIBE: dup: false qos: 1 retain: false rLength: 0 MessageID: 1 topics: [testtopic/#]
[client] sending subscribe message, topic: testtopic/#
[client] exit Subscribe
[net] obound priority msg to write, type *packets.SubscribePacket
[net] outgoing waiting for an outbound message
[net] Received Message
[net] logic got msg on ibound
[store] memorystore del: message 1 was deleted
[net] received suback, id: 1
[net] granted qoss [1]
[net] logic waiting for msg on ibound
发布一条天气预报消息
[client] enter Publish
[client] sending publish message, topic: testtopic/1
[net] obound wrote msg, id: 0
[net] outgoing waiting for an outbound message
发布客户端断开与broker的连接
[client] disconnecting
[net] obound priority msg to write, type *packets.DisconnectPacket
[net] outbound wrote disconnect, stopping
[pinger] keepalive stopped
[net] incoming stopped
[msgids] cleaned up
[client] disconnected
[store] memorystore closed
[net] Received Message
[net] logic got msg on ibound
[net] received publish, msgId: 0
[net] putting msg on onPubChan
[net] done putting msg on incomingPubChan
[net] logic waiting for msg on ibound
收到订阅消息：
Sub Client Topic : testtopic/1
Sub Client msg : Hello World，深圳天气晴朗5
[client] enter Subscribe
[client] SUBSCRIBE: dup: false qos: 1 retain: false rLength: 0 MessageID: 1 topics: [testtopic/#]
[client] sending subscribe message, topic: testtopic/#
[client] exit Subscribe
[net] obound priority msg to write, type *packets.SubscribePacket
[net] outgoing waiting for an outbound message
[net] Received Message
[net] logic got msg on ibound
[store] memorystore del: message 1 was deleted
[net] received suback, id: 1
[net] granted qoss [1]
[net] logic waiting for msg on ibound
Process exiting with code: 0