Package: iotrelay
IoT Relay: Giving Voice to Your ThingsRelease v1.2.3In greater and greater numbers, “things” are capable of gathering data
about their environment. These things have an interface to retrieve the
measurements being taken but contain no way of pushing this data to the
Internet. For example, home weather stations often contain only a USB
interface and no network capability. Other devices may have network
capability, such as ZigBee®, but still don’t have a direct way to send
data to Internet connected hosts.Internet of Things Relay is an application and framework for gathering
data from sources and relaying it to destinations. It is somewhat like
publish/subscribe except that it’s geared more toward devices that are
unable to initiate a connection (they must be polled to get at their
data).IoT Relay provides basic setup and matches data sources with interested
handlers. The rest of the work is left to plugins.InstallationIoT Relay is available via PyPI.$pipinstalliotrelayIt is also necessary to create an (initially empty) ini-style
file:~/.iotrelay.cfg.[itorelay]PluginsBefore IoT Relay can do anything useful, it needs plugins. There are
plugin types: source and handler. Source plugins generate data. Handler
plugins handle or do something with data that source plugins produce.
These definitions are intended to be open-ended. Although IoT Relay was
developed with the intention of relaying time-series type data between
remote sources and remote destinations, a handler could instead view
each datum as an event and trigger some action. Likewise, data source
plugins do not have to simply pass the data they are collecting. They
may process the data in some way before making it available to
interested handlers.Data Source Sample PluginA data source definition is a class which provides aget_reading()method and a constructor which accepts aconfigparameter. Theget_reading()method must return one or more instances of theReading()class or None. In this example,  create a file callediotrelay_sample_source.pyand enter the following code.# iotrelay_sample_source.pyimportrandomfromiotrelayimportReadingclassDataSource(object):def__init__(self,config):self.config=configdefget_readings(self):returnReading('sample',random.randint(1,100))IoT Relay uses setuptools to find plugins registered in theiotrelaygroup. Datasources should use the entry-point namesource. In the same directory asiotrelay_sample_source.py,
the following code should be placed insetup.py.# setup.pyfromsetuptoolsimportsetupsetup(name='iotrelay-sample-source',install_requires=['iotrelay'],py_modules=['iotrelay_sample_source'],entry_points={'iotrelay':['source=iotrelay_sample_source:DataSource']})Install the source plugin by typing:$pythonsetup.pyinstallData Handler Sample PluginLike the previous example, create a new directory with two files:# iotrelay_sample_handler.pyclassHandler(object):def__init__(self,config):self.config=configdefset_reading(self,reading):print(reading)# setup.pyfromsetuptoolsimportsetupsetup(name='iotrelay-sample-handler',install_requires=['iotrelay'],py_modules=['iotrelay_sample_handler'],entry_points={'iotrelay':['handler=iotrelay_sample_handler:Handler']})Install the handler plugin by typing:$pythonsetup.pyinstallPlugin ConfigurationThe minimal source plugin used in this example does not require any
configuration. The ‘reading types’ option in a handler’s configuration
specifies which reading types a handler will receive. In order to
receive readings from the ‘iotrelay-sample-source’ plugin, the
‘reading type’ option in the iotrelay-sample-handler would be ‘sample’.
This corresponds to the reading_type attribute set by the Reading
constructor when get_readings() was called.The section names correspond directly to the plugin names, as defined
insetup.py.; ~/.iotrelay.cfg[iotrelay][iotrelay-sample-source][iotrelay-sample-handler]reading types=sampleAny options specified in each plugins section will be passed to that
plugin’s constructor during initialization.Running IoT RelayStart IoT Relay with the following command:$iotrelayLicenseIoT Relay is licensed under The BSD 2-Clause License.LicenseCopyright © 2017, Emmanuel Levijarvi
All rights reserved.Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:Redistributions of source code must retain the above copyright notice, this
list of conditions and the following disclaimer.Redistributions in binary form must reproduce the above copyright notice,
this list of conditions and the following disclaimer in the documentation
and/or other materials provided with the distribution.THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS “AS IS”
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
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