Created by Benedict Wetzel

• 1. Introduction
• 2. Requirements
• 3. Prerequisits
• 4. Dependecies
• 5. Technical Overview

1. Introduction

This module can be used to publish information about the service on the MQTT-Broker and by doing so register it at the OI4-Service-Registry.

2. Requirements

The following requirements are covered by this module:

• NF20

3. Prerequisites

In order to use this module the following prerequisites should be met:

• The developer should have a working computer that can access the internet
• The developer should use a Linux-based OS
• The developer should have Node.js version 12.14.1 or higher installed
• The developer should have NPM version 7.10.0 or higher installed
• The developer should have at least some basic experience with Node.js

4. Dependencies

This module depends on the following items:

• mqttjs / MQTT.js v4.2.6

5. Technical overview

This module has the functionality to publish information about the service on the MQTT-Broker. It is able to listen to requests that concern the service and answer them respectively.

5.1 registeratOI4.js

This file contains all functionality of the module. It depends on the mqttjs NPM package.

Function	Description
setConfig	Sets the configuration of this module. Should be called before start.
start	This function starts the module. It subscribes to the topic on the MQTT-Broker, where all messages concerning this service are published. It then registers a ebent handler that listens to those messages and replies to them using the following functions. It also publishes Health-Messages every sixty seconds, as specified by the OI4.
pubHealth	This function is used to publish responses to Health-requests concerning the service on the MQTT-Broker
pubProfile	This function is used to publish responses to Profile-requests concerning the service on the MQTT-Broker
pubLicense	This function is used to publish responses to License-requests concerning the service on the MQTT-Broker
pubLicenseText	This function is used to publish responses to LicenseText-requests concerning the service on the MQTT-Broker
pubConfig	This function is used to publish responses to Config-requests concerning the service on the MQTT-Broker
pubPublicationList	This function is used to publish responses to PublicationList-requests concerning the service on the MQTT-Broker
buildmammessage	Builds the payload of the message which is used to publish the Master-Asset-Model of the service on the MQTT-Broker
buildmsg	Builds an OI4 compliant message which can then be published on the MQTT-Broker.

5.2 package.json

Sets the dependencies and is used by NPM to install the required NPM packages.