go - 无法使用Paho库连接到mosquitto 2.0

Question

我似乎无法从paho库(“github.com/eclipse/paho.golang/paho”)的golang连接到mosquitto 2.0代理。谁能指出我的方式的错误？
我从paho chat example中获取了连接逻辑，并尝试连接到我的本地主机服务器，但是原因码为135(未授权)。然后，我尝试使用mosquitto_pub成功连接到mosquitto服务器。在两种情况下，我都使用相同的用户名和密码。 mosquitto日志输出如下:

1608068903: New connection from 127.0.0.1:58794 on port 1883.
1608068903: Client <unknown> disconnected, not authorised.
1608069349: New connection from 127.0.0.1:58908 on port 1883.
1608069349: New client connected from 127.0.0.1:58908 as test (p5, c1, k60, u'username').

我正在使用的mosquitto_pub命令是:

snap run mosquitto.pub -h localhost -t hello -u username -P password -m hello -V mqttv5 -i test

golang代码为:

import (
    "context"
    "fmt"
    "github.com/eclipse/paho.golang/paho"
    log "github.com/sirupsen/logrus"
    "net"
)

func Test() {
    conn, err := net.Dial("tcp", "localhost:1883")
    if err != nil {
        log.Fatalf("Failed to connect to %s: %s", "localhost", err)
    }
    c := paho.NewClient(paho.ClientConfig{
        Router: paho.NewSingleHandlerRouter(func(m *paho.Publish) {
            log.Printf("%s : %s", m.Properties.User["chatname"], string(m.Payload))
        }),
        Conn: conn,
    })

    username := "username"
    password := "password"

    cp := &paho.Connect{
        KeepAlive:  30,
        ClientID:   "test",
        CleanStart: false,
        Username:   username,
        Password:   []byte(password),
    }
    ca, err := c.Connect(context.Background(), cp)
    if ca.ReasonCode != 0 {
        log.Fatalf("Failed to connect to %s : %d - %s", "localhost", ca.ReasonCode, ca.Properties.ReasonString)
    }
    if err != nil {
        log.Fatalln(err)
    }

    fmt.Printf("Connected to %s\n", "localhost")

}

Answer 1

将UsernameFlag和PasswordFlag添加到paho.Connect中，例如:

cp := &paho.Connect{
        KeepAlive:  30,
        ClientID:   "test",
        CleanStart: false,
        Username:   username,
        UsernameFlag: true,
        Password:   []byte(password),
        PasswordFlag: true,
    }

paho.golang文档需要工作，但是 mqtt v5 spec对此进行了介绍。我已经用Mosquitto 2.0.1对此进行了测试并成功连接。