mqtt-proxy

Description

The plugin mqtt-proxy only works in stream model, it help you to dynamic load balance by client_id of MQTT.

And this plugin both support MQTT protocol 3.1.* and 5.0.

Attributes

Name	Type	Requirement	Default	Valid	Description
protocol_name	string	required			Name of protocol, should be MQTT in normal.
protocol_level	integer	required			Level of protocol, it should be 4 for MQTT 3.1.*. it should be 5 for MQTT 5.0.
upstream	object	deprecated			Use separate upstream in the route instead.
upstream.host	string	required			the IP or host of upstream, will forward current request to.
upstream.ip	string	deprecated			Use "host" instead. IP address of upstream, will forward current request to.
upstream.port	number	required			Port of upstream, will forward current request to.

How To Enable

To enable this plugin, we need to enable the stream_proxy configuration in conf/config.yaml first. For example, the following configuration represents listening on the 9100 TCP port.

    ...
    router:
        http: 'radixtree_uri'
        ssl: 'radixtree_sni'
    stream_proxy:                 # TCP/UDP proxy
      only: false                 # needed if HTTP and Stream Proxy should be enabled
      tcp:                        # TCP proxy port list
        - 9100
    dns_resolver:
    ...

Then send the MQTT request to port 9100.

Creates a stream route, and enable plugin mqtt-proxy.

curl http://127.0.0.1:9080/apisix/admin/stream_routes/1 -H 'X-API-KEY: edd1c9f034335f136f87ad84b625c8f1' -X PUT -d '
{
    "plugins": {
        "mqtt-proxy": {
            "protocol_name": "MQTT",
            "protocol_level": 4
        }
    },
    "upstream": {
        "type": "roundrobin",
        "nodes": [{
            "host": "127.0.0.1",
            "port": 1980,
            "weight": 1
        }]
    }
}'

In case Docker is used in combination with MacOS host.docker.internal is the right parameter for host.

This plugin exposes a variable mqtt_client_id, and we can use it to load balance via the client id. For example:

curl http://127.0.0.1:9080/apisix/admin/stream_routes/1 -H 'X-API-KEY: edd1c9f034335f136f87ad84b625c8f1' -X PUT -d '
{
    "plugins": {
        "mqtt-proxy": {
            "protocol_name": "MQTT",
            "protocol_level": 4
        }
    },
    "upstream": {
        "type": "chash",
        "key": "mqtt_client_id",
        "nodes": [
        {
            "host": "127.0.0.1",
            "port": 1995,
            "weight": 1
        },
        {
            "host": "127.0.0.2",
            "port": 1995,
            "weight": 1
        }
        ]
    }
}'

MQTT connections with different client ID will be forwarded to different node via the consistent hash algorithm. If the client ID is missing, we will balance via client IP instead.

Delete Plugin

$ curl http://127.0.0.1:9080/apisix/admin/stream_routes/1 -H 'X-API-KEY: edd1c9f034335f136f87ad84b625c8f1' -X DELETE

The mqtt-proxy plugin has been deleted now.