Middleware for data flow integration and reconfiguration

Dependencies

The middleware requires json-c:

#!sh
sudo apt-get install libjson0 libjson0-dev

Installation

Download the git repository:

#!sh
git clone https://github.com/ComFlux/ComFlux-Middleware.git

The are included as submodules. The added submodules are: uthash, kerberros, and jsonschema-c.

#!sh
cd ComFlux-Middleware
git submodule init
git submodule update --recursive

Install the middleware:

#!sh
cmake [-DSSLENABLED:BOOL=ON] [-DKRBENABLED:BOOL=ON] [-DMQTTENABLED:BOOL=ON] .
make
sudo make install

The optional cmake arguments generate communication and access control modules relying on third party libraries.

Argument	Summary
-DMQTTENABLED:BOOL=ON	Enables building two com modules relying on MQTT.
-DSSLENABLED:BOOL=ON	Enables building an SSL com module and a certificate based access control module.
-DKRBENABLED:BOOL=ON	Enables building a Kerberos access control module.

To install mosquitto:

#!sh
sudo apt-add-repository ppa:mosquitto-dev/mosquitto-ppa
sudo apt-get update
sudo apt-get install libmosquitto

To install OpensSSL:

#!sh
sudo apt-get install libssl-dev

The Kerberos module uses krb5 library linked as a submodule.

API structure

Through the API the following headers are available:

File	Summary
middleware.h	Communication and configuration functionality with the middleware core.
endpoint.h	Endpoint definitions and endpoint specific commands.
load_mw_config.h	To facilitate middleware deployment configuration can be applied from json structures or fles.

Examples

Simple source - sink

Run a simple source - sink communication by opening two terminals and typing

#!sh
cd build/bin/examples
./simple_source src_mw_cfg.json

#!sh
cd build/bin/examples
./simple_sink 127.0.0.1:1503 snk_mw_cfg.json

Resource discovery

Map the sink to the source by querying a Resource Discovery Component for the source. First, run an RDC

#!sh
rdc

Then start lookup_source and lookup_sink.

#!sh
cd build/bin/examples
./lookup_source src_mw_cfg.json

#!sh
cd build/bin/examples
./lookup_sink snk_mw_cfg.json "\"ep_name\" = \"ep_source\"

Dynamic connection management and reconfiguration

Watch this space

Compile your new component

The distribution provides the core and the library of the middleware. To compile your component run:

#!sh
 cc -o your_component your_component.c -lmiddleware_api -lmiddleware_utils

All functions presented so far are implemented in the middleware_api. The middleware_utils library contains data structures used in the mw and functions to manipulate them. For instance json, hashmap, array, message.

Documentation

For the basic usage of ComFlux, here is a detailed tutorial: ComFlux: Dynamic creation of pervasive applications from plug-and-play modules

Here is an article detailing the model and applications of ComFlux: ComFlux: External Composition and Adaptation of Pervasive Applications

We also have the following tutorial proposal: ComFlux: Dynamic creation of pervasive applications from plug-and-play modules