MQTT

• Introduction
• Compatibility matrix
• Prerrequisites
• Parameters
• Manual execution
• Configuration in Pandora
• Agent and modules generated by the plugin

Introduction

The purpose of this plugin is to be able to receive messages from an MQTT topic, having the possibility to apply filters such as words or the text format of the expected messages.

The plugin performs all these actions through a client with which it connects.

Compatibility matrix

Systems where tested	Rocky linux, Fedora 34
Systems where it works	Any linux system

Prerrequisites

• Connectivity to the host and topic from which messages are to be received is required.

Parameters

Connectivity parameters

-i, --host	MQTT' server address
-p, --port	MQTT' port address

Parameters for posting message in topic

-m, --message	MQTT message to be sent
-s, --publish_topic	MQTT publication topic

Parameters for receiving messages and filtering

-r, --suscribe_topic	MQTT subscription topic
-t, --time	Duration of run time in seconds
-f, --filter	Filter (word) to apply. Only messages containing the word will be received.
-k, --format	Text format of the expected messages to be received
-l, --limit	Message limit

Pandora configuration parameters

--agent_name	Name of the agent to be created or in which the module is to be created
--interval	Agent monitoring interval
--temporal	PandoraFMS temporary directory
--data_dir	PandoraFMS Data Directory
--group	PandoraFMS Target Group
--transfer_mode	Data transfer mode, local or tentacle
--tentacle_client	Tentacle client path, by default "tentacle_client".
--tentacle_opts	Tentacle extra options
--tentacle_port	Tentacle port
--tentacle_address	Tentacle IP

Extra parameters

--log_file

Path where the log file will be generated

Manual execution

The plugin execution format is as follows:

./pandora_mqtt --agent_name < agent name > --host < host > --port < port >  \
[ --message < message > ] [ --publish_topic < publish_topic > ] \
[ --subscribe_topic < subscribe_topic > ] [ --time < time > ] \
[ --filter < filter > ] [ --format < format > ] [ --limit < limit > ] \
[ --transfer_mode < local o tentacle > ] [ --tentacle_port < tentacle_port > ] \
[ --tentacle_address < tentacle_address > ] [ --tentacle_client < tentacle client path ] \
[ --tentacle_opts < tentacle extra options ][ -g < group > ] [ --data_dir < data dir > ] \
[ --temporal < temporary directory path > ] [ --interval < interval agent monitorings in seconds > ] \ 
[ --logfile < logfile path > ]

 

Configuration in Pandora

To configure the plugin in PandoraFMS, the following steps must be followed:

1.Upload the plugin to PandoraFMS, for example in the following path:

/etc/pandora/plugin

2. Go to the plugins section and create a new one:

    3. Name, description and timeout are added:

4. The path to the plugin is added to the command and the necessary parameters for the execution of the plugin are added.

For each parameter a macro must be configured, being the syntax of this macro the following : _fieldx_, where x is the positional number of the parameter, for example in the following image we see the parameters that are necessary to use to subscribe to a topic and receive messages.

5. Configure the above macros, adding in each one the value of the parameter:

6. Once configured, you should create a module in an agent that executes the plugin. In the modules menu of an agent we create a new plugin type module:

7.In the module configuration menu, give it a name, select the previously configured plugin and click on "create".

8.In the agent selected with the --agent_name parameter, a new module of list format will be created, which will contain the messages received by the plugin execution.

Agent and modules generated by the plugin

• The plugin will create an agent with the selected name with the --agent_name parameter. Or in its defect it will insert the module in an agent that already exists with this name.
• The plugin will create a module:

MQTT.<suscribe topic>.results

Results obtained in list format, i.e. the messages received that have passed the filters used.