emqx4.3/examples/auto_subscribe.conf.example

##--------------------------------------------------------------------
## Auto Subscribe
##
## Subscribe the Topics automatically when client connected
##--------------------------------------------------------------------

auto_subscribe.topics = [
    {
        ## Topic name, placeholders are supported
        ## For example: client/${clientid}/username/${username}/host/${host}/port/${port}
        topic = "/auto/${clientid}",

        ## QoS
        qos = 0,

        ## Retain Handling
        ## Value: 0 | 1 | 2
        rh = 0,

        ## Retain As Publish
        ## Value: 0 | 1
        rap = 0,

        ## No Local
        ## Value: 0 | 1
        nl = 0
    },
    {topic = "/foo/${username}/#", qos = 1},
    {topic = "/boo/${ip}/+"}
]