GMQ 是一个纯 Go MQTT 客户端。该库与 MQTT 版本 3.1.1 兼容。该库提供了 Go 包和命令行应用程序。
$ go get -u github.com/yosssi/gmq/... package main
import (
"fmt"
"os"
"os/signal"
"github.com/yosssi/gmq/mqtt"
"github.com/yosssi/gmq/mqtt/client"
)
func main () {
// Set up channel on which to send signal notifications.
sigc := make ( chan os. Signal , 1 )
signal . Notify ( sigc , os . Interrupt , os . Kill )
// Create an MQTT Client.
cli := client . New ( & client. Options {
// Define the processing of the error handler.
ErrorHandler : func ( err error ) {
fmt . Println ( err )
},
})
// Terminate the Client.
defer cli . Terminate ()
// Connect to the MQTT Server.
err := cli . Connect ( & client. ConnectOptions {
Network : "tcp" ,
Address : "iot.eclipse.org:1883" ,
ClientID : [] byte ( "example-client" ),
})
if err != nil {
panic ( err )
}
// Subscribe to topics.
err = cli . Subscribe ( & client. SubscribeOptions {
SubReqs : [] * client. SubReq {
& client. SubReq {
TopicFilter : [] byte ( "foo" ),
QoS : mqtt . QoS0 ,
// Define the processing of the message handler.
Handler : func ( topicName , message [] byte ) {
fmt . Println ( string ( topicName ), string ( message ))
},
},
& client. SubReq {
TopicFilter : [] byte ( "bar/#" ),
QoS : mqtt . QoS1 ,
Handler : func ( topicName , message [] byte ) {
fmt . Println ( string ( topicName ), string ( message ))
},
},
},
})
if err != nil {
panic ( err )
}
// Publish a message.
err = cli . Publish ( & client. PublishOptions {
QoS : mqtt . QoS0 ,
TopicName : [] byte ( "bar/baz" ),
Message : [] byte ( "testMessage" ),
})
if err != nil {
panic ( err )
}
// Unsubscribe from topics.
err = cli . Unsubscribe ( & client. UnsubscribeOptions {
TopicFilters : [][] byte {
[] byte ( "foo" ),
},
})
if err != nil {
panic ( err )
}
// Wait for receiving a signal.
<- sigc
// Disconnect the Network Connection.
if err := cli . Disconnect (); err != nil {
panic ( err )
}
} // Create an MQTT Client.
cli := client . New ( & client. Options {
ErrorHandler : func ( err error ) {
fmt . Println ( err )
},
})
// Terminate the Client.
defer cli . Terminate ()
// Connect to the MQTT Server.
err := cli . Connect ( & client. ConnectOptions {
// Network is the network on which the Client connects to.
Network : "tcp" ,
// Address is the address which the Client connects to.
Address : "iot.eclipse.org:1883" ,
// TLSConfig is the configuration for the TLS connection.
// If this property is not nil, the Client tries to use TLS
// for the connection.
TLSConfig : nil ,
// CONNACKTimeout is timeout in seconds for the Client
// to wait for receiving the CONNACK Packet after sending
// the CONNECT Packet.
CONNACKTimeout : 10 ,
// PINGRESPTimeout is timeout in seconds for the Client
// to wait for receiving the PINGRESP Packet after sending
// the PINGREQ Packet.
PINGRESPTimeout : 10 ,
// ClientID is the Client Identifier of the CONNECT Packet.
ClientID : [] byte ( "clientID" ),
// UserName is the User Name of the CONNECT Packet.
UserName : [] byte ( "userName" ),
// // Password is the Password of the CONNECT Packet.
Password : [] byte ( "password" ),
// CleanSession is the Clean Session of the CONNECT Packet.
CleanSession : true ,
// KeepAlive is the Keep Alive of the CONNECT Packet.
KeepAlive : 30 ,
// WillTopic is the Will Topic of the CONNECT Packet.
WillTopic : [] byte ( "willTopic" ),
// WillMessage is the Will Message of the CONNECT Packet.
WillMessage : [] byte ( "willMessage" ),
// WillQoS is the Will QoS of the CONNECT Packet.
WillQoS : mqtt . QoS0 ,
// WillRetain is the Will Retain of the CONNECT Packet.
WillRetain : true ,
})
if err != nil {
panic ( err )
} // Create an MQTT Client.
cli := client . New ( & client. Options {
ErrorHandler : func ( err error ) {
fmt . Println ( err )
},
})
// Terminate the Client.
defer cli . Terminate ()
// Read the certificate file.
b , err := ioutil . ReadFile ( "/path/to/crtFile" )
if err != nil {
panic ( err )
}
roots := x509 . NewCertPool ()
if ok := roots . AppendCertsFromPEM ( b ); ! ok {
panic ( "failed to parse root certificate" )
}
tlsConfig = & tls. Config {
RootCAs : roots ,
}
// Connect to the MQTT Server using TLS.
err := cli . Connect ( & client. ConnectOptions {
// Network is the network on which the Client connects to.
Network : "tcp" ,
// Address is the address which the Client connects to.
Address : "iot.eclipse.org:1883" ,
// TLSConfig is the configuration for the TLS connection.
// If this property is not nil, the Client tries to use TLS
// for the connection.
TLSConfig : tlsConfig ,
})
if err != nil {
panic ( err )
} // Create an MQTT Client.
cli := client . New ( & client. Options {
ErrorHandler : func ( err error ) {
fmt . Println ( err )
},
})
// Terminate the Client.
defer cli . Terminate ()
// Subscribe to topics.
err = cli . Subscribe ( & client. SubscribeOptions {
SubReqs : [] * client. SubReq {
& client. SubReq {
// TopicFilter is the Topic Filter of the Subscription.
TopicFilter : [] byte ( "foo" ),
// QoS is the requsting QoS.
QoS : mqtt . QoS0 ,
// Handler is the handler which handles the Application Message
// sent from the Server.
Handler : func ( topicName , message [] byte ) {
fmt . Println ( string ( topicName ), string ( message ))
},
},
& client. SubReq {
TopicFilter : [] byte ( "bar/#" ),
QoS : mqtt . QoS1 ,
Handler : func ( topicName , message [] byte ) {
fmt . Println ( string ( topicName ), string ( message ))
},
},
},
})
if err != nil {
panic ( err )
} // Create an MQTT Client.
cli := client . New ( & client. Options {
ErrorHandler : func ( err error ) {
fmt . Println ( err )
},
})
// Terminate the Client.
defer cli . Terminate ()
// Publish a message.
err = cli . Publish ( & client. PublishOptions {
// QoS is the QoS of the PUBLISH Packet.
QoS : mqtt . QoS0 ,
// Retain is the Retain of the PUBLISH Packet.
Retain : true ,
// TopicName is the Topic Name of the PUBLISH Packet.
TopicName : [] byte ( "bar/baz" ),
// Message is the Application Message of the PUBLISH Packet.
Message : [] byte ( "testMessage" ),
})
if err != nil {
panic ( err )
} // Create an MQTT Client.
cli := client . New ( & client. Options {
ErrorHandler : func ( err error ) {
fmt . Println ( err )
},
})
// Terminate the Client.
defer cli . Terminate ()
// Unsubscribe from topics.
err = cli . Unsubscribe ( & client. UnsubscribeOptions {
// TopicFilters represents a slice of the Topic Filters.
TopicFilters : [][] byte {
[] byte ( "foo" ),
},
})
if err != nil {
panic ( err )
} // Create an MQTT Client.
cli := client . New ( & client. Options {
ErrorHandler : func ( err error ) {
fmt . Println ( err )
},
})
// Terminate the Client.
defer cli . Terminate ()
// Disconnect the network connection.
if err := cli . Disconnect (); err != nil {
panic ( err )
}安装后，您可以通过执行gmq-cli命令启动 MQTT 客户端命令行应用程序。
$ gmq-cli
gmq-cli >您可以通过执行help GMQ Client 命令来查看所有 GMQ Client 命令。
gmq-cli > help
GMQ Client 0.0.1
Usage:
conn establish a Network Connection and send a CONNECT Packet to the Server
disconn send a DISCONNECT Packet to the Server and disconnect the Network Connection
help print this help message
pub send a PUBLISH Packet to the Server
quit quit this process
sub send a SUBSCRIBE Packet to the Server
unsub send a UNSUBSCRIBE Packet to the Server您可以通过使用-help标志执行命令来查看 GMQ 客户端命令的所有标志。
gmq-cli > conn -help
Usage:
-P= " " : Password
-c=true: Clean Session
-crt= " " : the path of the certificate authority file to verify the server connection
-ct=30: Timeout in seconds for the Client to wait for receiving the CONNACK Packet after sending the CONNECT Packet
-h= " localhost " : host name of the Server which the Client connects to
-i= " " : Client identifier for the Client
-k=60: Keep Alive measured in seconds
-n= " tcp " : network on which the Client connects to the Server
-p=1883: port number of the Server which the Client connects to
-pt=30: Timeout in seconds for the Client to wait for receiving the PINGRESP Packet after sending the PINGREQ Packet
-u= " " : User Name
-wm= " " : Will Message
-wq=0: Will QoS
-wr=false: Will Retain
-wt= " " : Will Topic
