ltm rule command MQTT topic

iRule(1)		      BIG-IP TMSH Manual		      iRule(1)



MQTT::topic
       Manipulate topic(s) of MQTT message.

SYNOPSIS
       MQTT::topic (('replace' TOPIC) |
			    ('count') |
			    ('list') |
			    ('index' INDEX) |
			    ('add' TOPIC ('0' | '1' | '2')?) |
			    ('delete' TOPIC) |
			    ('qos' TOPIC))?

DESCRIPTION
       This command can be used to manipulate topic(s) of MQTT message.  This
       command is valid only for following MQTT message types:

	   PUBLISH
	   SUBSCRIBE
	   UNSUBSCRIBE

       Syntax

       MQTT::topic [ replace  | count | list | index
        |
		     add  [] | delete  ]

       MQTT::topic
	   * Get the topic-name of MQTT PUBLISH message. Or the first topic of
       a SUBSCRIBE or UNSUBSCRIBE message.

       MQTT::topic replace 
	   * Set the topic-name of MQTT PUBLISH message to specified string.
	     This command is valid only for PUBLISH messages.

       MQTT::topic count
	   * Get the number of topics in MQTT SUBSCRIBE and UNSUBSCRIBE
       messages.

       MQTT::topic list
	   * Get the list of topics in MQTT SUBSCRIBE and UNSUBSCRIBE
       messages.

       MQTT::topic index 
	   * Get the topics at index  in the list of topics in
       MQTT SUBSCRIBE and UNSUBSCRIBE messages.

       MQTT::topic qos 
	   * This command is valid for SUBSCRIBE messages only. It returns the
       QoS value of the given .

       MQTT::topic add  []
	   * For SUBSCRIBE messages, add the specified  and 
       to the end of list of topics.
	      can only be 0,1, or 2. If not specified QoS 0 will be used.
	     For UNSUBSCRIBE messages, add the specified  to the
       end of list of topics.
	     UNSUBSCRIBE messages do not need QoS. If supplied, it will be
       ignored.

       MQTT::topic delete 
	   * Delete the specified  and its qos from the topics in
       MQTT SUBSCRIBE and UNSUBSCRIBE messages.

RETURN VALUE
       When called without an argument, this command returns the topic-name of
       MQTT PUBLISH message, or the topic-name of the first topic of MQTT
       SUBSCRIBE and UNSUBSCRIBE messages.

VALID DURING
       MQTT_CLIENT_INGRESS MQTT_SERVER_INGRESS MQTT_CLIENT_DATA
       MQTT_SERVER_DATA

EXAMPLES
	Automatically assign a subscription to the client for topic "$SYS/broker/alerts/critical":
	when MQTT_CLIENT_INGRESS {
	    set cmtype [MQTT::type]
	    if { $cmtype == "SUBSCRIBE" } {
		set topic_count [MQTT::topic count]
		set mid [MQTT::packet_id]
		set countmap($mid) $topic_count
		MQTT::topic add "$SYS/broker/alerts/critical" 0
	    }
	}

	when MQTT_SERVER_INGRESS {
	    set smtype [MQTT::type]
	    if {$smtype == "SUBACK"} {
	       set mid [MQTT::packet_id]
	       set tc countmap($mid)
	       set return_codes [MQTT::return_code_list]
	       set return_codes [lreplace $return_codes $tc $tc]
	       MQTT::replace type SUBACK packet_id $mid return_code_list $return_codes
	    }
	}

HINTS
SEE ALSO
CHANGE LOG
       @BIGIP-13.0.0 --First introduced the command.



BIG-IP				  2017-01-31			      iRule(1)