go-zeromq
Go bindings for zerosvc
Event field mapping
MQTTv3 format is whole event serialized into JSON AMQP/MQTTv5 uses headers and puts body as-is
| event | MQTTv3 | MQTTv5 (future) | AMQP |
|---|---|---|---|
| Reply to | body json | UserProperty[reply_to] | Header[reply_to] |
| Redelivered | DUP transport flag | DUP transport flag | redelivered flag |
| RetainTill | retain flag (NO TTL) | retain + Expiry | no support |
| Headers | body JSON | UserProperty | Headers[] |
| Body | body JSON['body'] | Body | Body |
- extra transport control headers:
| header key | MQTTv3 | MQTTv5 | AMQP |
|---|---|---|---|
_transport_ttl |
--- | Expiry | TTL |
node-name |
--- | retained | AppId |
correlation-id |
--- | retained | CorrelationId |
user-id |
--- | retained | UserId |
other:
- topic of incoming messages is encoded in `RoutingKey
MQTT URL options
- username/pass - same as basic auth e.g.
tcp://mqttuser:mqttpass@127.0.0.1:1883 - TLS - just change proto to
tls-tls://mqtt.example.com:8883 - query options
- CA -
tls://mqtt.example.com:8883/?ca=/my/ca/path.crt - client cert (key + cert in one file) -
tls://mqtt.example.com:8883/?cert=/path/certandkey.pem - client cert (key, cert in separate file) -
tls://mqtt.example.com:8883/?cert=/path/cert.pem&certkey=/path/certkey.pem
- CA -
Examples
Create node
tr := zerosvc.NewTransport(zerosvc.TransportMQTT,"tcp://127.0.0.1:1883",zerosvc.TransportMQTTConfig{})
node := zerosvc.NewNode("unique-node-name")
tr.Connect()
node.SetTransport(tr)prepare and send event. Prepare() takes care of checksums/signatures for the event
e := zerosvc.Event{
Headers: map[string]interface{}{
"test": "header",
},
Body: []byte("hay"),
}
e.Prepare()
node.SendEvent("dpp/ev",e)
Quirks
- Due to how MQTT libraries work only first user/password is used for all urls.
