The SensorThings Provisioning Service is supposed to make it easier to set up a SensorThings server (e.g. GOST) for an IoT landscape. It allows the maintenance of all metadata in the SensorThings server using a single JSON object while the value in mandatory field name is used as a unique identifier for Things, Locations, Datastreams, Sensors and ObservedProperties. Objects of the same kind with the same name will only be created once. Existing objects (identified via their name field) will be patched. The service will not delete any objects already existing in GOST server.
In addition, the service allows the definition of statements to be created in a LinkSmart Data Processing Agent so that the results of the statements are being published to the SensorThings server via an MQTT broker. A possible use case for this is the conversion of data being published by a LinkSmart Device Gateway in SenML format into OGC format. A statement can be defined for each Datastream in the properties field of the Datastream´s corresponding Thing (see example below). The Datastream and the statement property need to have the same name.
Use the following docker-compose file to set up an exemplary deployment using the public LinkSmart demo broker:
version: '3.5'
services:
gost-db:
image: geodan/gost-db
container_name: "gost-db"
environment:
POSTGRES_DB: gost
POSTGRES_USER: postgres
POSTGRES_PASSWORD: postgres
gost:
image: geodan/gost
container_name: "gost"
environment:
GOST_DB_HOST: gost-db
GOST_SERVER_EXTERNAL_URI: http://<address_of_your_host>:8080/
GOST_MQTT_HOST: demo.linksmart.eu
GOST_MQTT_PORT: 8883
GOST_MQTT_SSL: "true"
GOST_MQTT_CA_CERT_FILE: /etc/ssl/cert.pem
GOST_MQTT_USERNAME: linksmart
GOST_MQTT_PASSWORD: demo
GOST_MQTT_CLIENTID: gost_linksmart
GOST_SERVER_MAX_ENTITIES: 1000
GOST_LOG_VERBOSE_FLAG: "true"
dashboard:
image: geodan/gost-dashboard
container_name: "dashboard"
ports:
- 8080:8080
sensorthings-provisioning:
image: linksmart/sensorthings-provisioning
container_name: "sensorthings-provisioning"
ports:
- 8081:8080
environment:
GOST_BASE_URI: http://dashboard:8080/
AGENT_BASE_URI: http://agent:8319/
agent:
image: linksmart/dpa:snapshot
container_name: "agent"
ports:
- 8319:8319
environment:
- agent_id=linksmart
- connection_broker_mqtt_hostname=demo.linksmart.eu
- connection_broker_mqtt_port=8883
- connection_broker_mqtt_security_certificateBaseSecurityEnabled=true
- messaging_client_mqtt_security_user=linksmart
- messaging_client_mqtt_security_password=demo
- "api_events_mqtt_topic_incoming_SenML=LS/v2/DGW/#"The provisioning service can be accessed on port 8081 at endpoint /provisioning/. The POST body needs to be a list of Things in the format defined for the request body of "Post Thing ULTIMATE" requests to GOST (Observations are currently not handled). See here for an example setting up linksmart-black and linksmart-apple with their sensors in GOST and converting the SenML data into OGC format using the Data Processing Agent:
{
"Things": [
{
"name": "linksmart-black",
"description": "Raspberry Pi",
"properties": {
"organisation": "FIT",
"owner": "Jannis Warnat",
"linksmart-black-temperature": {
"statement": "select e[0].v as result from SenML(bn=\"linksmart-black/\")"
},
"linksmart-black-humidity": {
"statement": "select e[1].v as result from SenML(bn=\"linksmart-black/\")"
}
},
"Locations": [
{
"name": "C5.110",
"description": "Office Jannis Warnat",
"encodingType": "application/vnd.geo+json",
"location": {
"coordinates": [
7.203599523171596,
50.74929555
],
"type": "Point"
}
}
],
"Datastreams": [
{
"name": "linksmart-black-temperature",
"unitOfMeasurement": {
"name": "Celsius",
"symbol": "C",
"definition": "http://www.qudt.org/qudt/owl/1.0.0/unit/Instances.html#Celsius"
},
"description": "Temperature measurement from linksmart-black",
"observationType": "http://www.opengis.net/def/observationType/OGC-OM/2.0/OM_Measurement",
"ObservedProperty": {
"name": "Temperature",
"description": "Temperature in situ",
"definition": "http://www.qudt.org/qudt/owl/1.0.0/quantity/Instances.html#Temperature"
},
"Sensor": {
"name": "DHT22",
"description": "Digital temperature and humidity sensor",
"encodingType": "application/pdf",
"metadata": "https://www.sparkfun.com/datasheets/Sensors/Temperature/DHT22.pdf"
}
},
{
"name": "linksmart-black-humidity",
"unitOfMeasurement": {
"name": "Percentage",
"symbol": "%",
"definition": "https://www.quora.com/What-is-the-unit-of-humidity"
},
"description": "Humidity measurement from linksmart-black",
"observationType": "http://www.opengis.net/def/observationType/OGC-OM/2.0/OM_Measurement",
"ObservedProperty": {
"name": "Relative humidity",
"description": "Relative humidity in situ",
"definition": "https://en.wikipedia.org/wiki/Relative_humidity"
},
"Sensor": {
"name": "DHT22",
"description": "Digital temperature and humidity sensor",
"encodingType": "application/pdf",
"metadata": "https://www.sparkfun.com/datasheets/Sensors/Temperature/DHT22.pdf"
}
}
]
},
{
"name": "linksmart-apple",
"description": "Raspberry Pi",
"properties": {
"organisation": "FIT",
"owner": "Farshid Tavakolizadeh",
"linksmart-apple-temperature": {
"statement": "select e[0].v as result from SenML(bn=\"linksmart-apple/\")"
},
"linksmart-apple-humidity": {
"statement": "select e[1].v as result from SenML(bn=\"linksmart-apple/\")"
}
},
"Locations": [
{
"name": "C5.140",
"description": "Middle Room",
"encodingType": "application/vnd.geo+json",
"location": {
"coordinates": [
7.203599523171596,
50.74929555
],
"type": "Point"
}
}
],
"Datastreams": [
{
"name": "linksmart-apple-temperature",
"unitOfMeasurement": {
"name": "Celsius",
"symbol": "C",
"definition": "http://www.qudt.org/qudt/owl/1.0.0/unit/Instances.html#Celsius"
},
"description": "Temperature measurement from linksmart-apple",
"observationType": "http://www.opengis.net/def/observationType/OGC-OM/2.0/OM_Measurement",
"ObservedProperty": {
"name": "Temperature",
"description": "Temperature in situ",
"definition": "http://www.qudt.org/qudt/owl/1.0.0/quantity/Instances.html#Temperature"
},
"Sensor": {
"name": "DHT22",
"description": "Digital temperature and humidity sensor",
"encodingType": "application/pdf",
"metadata": "https://www.sparkfun.com/datasheets/Sensors/Temperature/DHT22.pdf"
}
},
{
"name": "linksmart-apple-humidity",
"unitOfMeasurement": {
"name": "Percentage",
"symbol": "%",
"definition": "https://www.quora.com/What-is-the-unit-of-humidity"
},
"description": "Humidity measurement from linksmart-apple",
"observationType": "http://www.opengis.net/def/observationType/OGC-OM/2.0/OM_Measurement",
"ObservedProperty": {
"name": "Relative humidity",
"description": "Relative humidity in situ",
"definition": "https://en.wikipedia.org/wiki/Relative_humidity"
},
"Sensor": {
"name": "DHT22",
"description": "Digital temperature and humidity sensor",
"encodingType": "application/pdf",
"metadata": "https://www.sparkfun.com/datasheets/Sensors/Temperature/DHT22.pdf"
}
}
]
}
]
}Notice that the data from linksmart-black and linksmart-apple is appearing as observations in the GOST server.