FIWARE System Handle

Introduction

What is a System Handle?

A System Handle is a plugin that allows a certain middleware or communication protocol to speak the same language used by the eProsima Integration Service, that is, Extensible and Dynamic Topic Types for DDS (xTypes); specifically, Integration Service bases its intercommunication abilities on eProsima's open source implementation for the xTypes protocol, that is, eProsima xTypes.

The FIWARE SystemHandle

This repository contains the source code of Integration Service System Handle for the FIWARE middleware protocol, widely used in the robotics field.

The main purpose of the FIWARE System Handle is that of establishing a connection between a FIWARE's Context Broker and an application running over a different middleware implementation. This is the classic use-case approach for Integration Service.

Dependencies

This section provides a list of the dependencies needed in order to compile FIWARE System Handle.

Asio: C++ library for network and low-level I/O programming.
cURLpp: C++ wrapper for libcURL.
cURL: Command-line tool for getting or sending data using URL syntax.

These libraries can be installed using your Linux distribution package manager with the following command:

sudo apt-get install -y libcurlpp-dev libasio-dev libcurl4-openssl-dev

Configuration

Integration Service is configured by means of a YAML configuration file, which specifies the middlewares, topics and/or services involved in the intercommunication process, as well as their topic/service types and the data exchange flow. This configuration file is loaded during runtime, so there is no need to recompile any package before switching to a whole new intercommunication architecture.

To get a more precise idea on how these YAML files have to be filled and which fields they require in order to succesfully configure and launch an Integration Service project, please refer to the dedicated configuration section of the official documentation.

Regarding the FIWARE System Handle, there are several specific parameters which must be configured for the FIWARE middleware. These parameters are mandatory, and fall as suboptions of the main five sections described in the Configuration chapter of Integration Service repository:

systems: The system type must be fiware. In addition to the type and types-from fields, the FIWARE System Handle accepts some specific configuration fields:
```
systems:
  fiware:
    type: fiware
    host: localhost
    port: 1026
```
- port: The specific port where the FIWARE's Context Broker will listen for incoming connections. This field is required.
- host: The IP address of the *FIWARE's Context Broker`. This field is required.

Examples

There are several Integration Service examples using the FIWARE System Handle available in the project's main source code repository.

Some of these examples, where the FIWARE System Handle plays a different role in each of them, are introduced here.

FIWARE - ROS 2 bridge (publisher - subscriber)

In this example, Integration Service uses both this FIWARE System Handle and the ROS 2 System Handle to transmit data coming from a ROS 2 publisher into the FIWARE's Context Broker, so that it can be consumed by FIWARE entities entities named equally to the Integration Service's topic name; and viceversa.

The configuration file used by Integration Service for this example can be found here.

For a detailed step by step guide on how to build and test this example, please refer to the dedicated section in the official documentation.

Compilation flags

Besides the global compilation flags available for the whole Integration Service product suite, there are some specific flags which apply only to the FIWARE System Handle; they are listed below:

BUILD_FIWARE_TESTS: Allows to specifically compile the FIWARE System Handle unitary and integration tests; this is useful to avoid compiling each System Handle's test suite present in the colcon workspace, which is what would happen if using the BUILD_TESTS flag; and thus, minimizing the building time; to use it, after making sure that the FIWARE System Handle is present in the colcon workspace, the following command must be executed:
```
~/is_ws$ colcon build --cmake-args -DBUILD_FIWARE_TESTS=ON
```

Documentation

The official documentation for the FIWARE System Handle is included within the official Integration Service documentation, hosted by Read the Docs, and comprises the following sections:

License

This repository is open-sourced under the Apache-2.0 license. See the LICENSE file for more details.

Getting help

If you need support you can reach us by mail at support@eProsima.com or by phone at +34 91 804 34 48.

Supported by ROSIN - ROS-Industrial Quality-Assured Robot Software Components. More information: rosin-project.eu

This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement no. 732287.

eProsima / FIWARE-SH