FIWARE Context Provider for the Weather Underground API

General

This context provider serves as a bridge between the orion context broker and the weather underground API. This allows one to include weather station data from weather underground in NGSIv2 entities. The context provider exptects the following format as entity id:

urn:ngsi-ld:WeatherObserved:<Weather Underground Station ID>

Other formats are not supported at the moment. The definition of the data model WeatherObserved is part of the Smart Data Models and can be looked up here.

Getting started

The context provider can be retrieved from the docker hub. Use the following command to spin up a new container named wunderground:

docker run -d --name wunderground -e DEBUG=provider:* -e PROVIDER_WUNDERGROUND_API_KEY=<API key> smartcitylab2050/provider.wunderground

Environment variables

The context provider is configured using environment variables. By default, only the PROVIDER_WUNDERGROUND_API_KEY is required to spin up an instance of the context provider on port 3000 with a cache expire time of one minute.

Key	Default Value	Description
PROVIDER_PORT	3000	Port used by the context provider
PROVIDER_WUNDERGROUND_API_KEY	none	Weather underground API key
PROVIDER_CACHE_ENABLED	true	Enables / Disables the caching mechanism (reduces API requests)
PROVIDER_CACHE_EXPIRE_TIME	60	Cache expire time in seconds
DEBUG	none	Debug log filter (set to provider:* to print all provider related logs)

Registering the context provider

The context provider needs to be registered at the orion context broker. This can be done using the following curl command. Adjust the station id, attributes and url to match your environment. For a complete list of all supported attributes, see here.

curl -iX POST 'http://localhost:1026/v2/registrations' \
     -H 'Content-Type: application/json'
     -d '{
         "description": "Weather underground provider",
         "dataProvided": {
             "entities": [
                 {
                     "id": "urn:ngsi-ld:WeatherObserved:<Station ID>",
                     "type": "WeatherObserved"
                 }
             ],
             "attrs": [
                 "relativeHumidity"
             ]
         },
         "provider": {
             "http": {
                 "url": "http://wunderground:3000/v2"
             }
         }
     }'

Attributes provided

The following attributes can be queried from the context provider. Have a look at the API documentation here for more information about the attributes. All attributes with units are converted to SI base units to match the default units of the WeatherObserved data model.

• atmosphericPressure
• dataProvider
• dewPoint
• location
• precipitation
• relativeHumidity
• solarRadiation
• temperature
• windDirection
• windSpeed