Modify getting started to use IoTA JSON

doc/getting-started.md

@@ -1,35 +1,52 @@
-## Getting Started
+# Getting Started
 
-Every IoT Agent which uses the library is different, but the concepts for provisioning IoT devices remain the same
-regardless of protocol.
+-   [Intrioduction](#introduction)
+-   [IoT Agent settings - `config.js`](#iot-agent-settings---configjs)
+-   [Provisioning a Config Group](#provisioning-a-config-group)
+-   [Provisioning an Individual Device](#provisioning-an-individual-device)
+-   [Receiving measures from devices](#receiving-measures-from-devices)
+    -   [Receiving a measure from a known Device](#receiving-a-measure-from-a-known-device)
+    -   [Receiving a measure from an anonymous Device](#receiving-a-measure-from-an-anonymous-device)
 
-### `config.js` - IoT Agent settings
+## Introduction
+
+In this guide we will be using the IoT Agent JSON as an example to demonstrate how to provision config groups, devices
+and how to receive measures from devices.
+
+Be aware that every IoT Agent which uses the library is different, but the concepts for provisioning IoT devices remain
+the same regardless of protocol.
+
+The IoT Agent JSON is a simple IoT Agent which uses JSON payloads to send and receive data. It is a good starting point
+for understanding the how an IoT Agent works since it uses JSON payloads to send and receive data.
+
+## IoT Agent settings - `config.js`
 
 The `config.js` holds common information about the interactions between the Agent and the Context Broker. Additional
-custom settings may also be required dependent upon the actual IoT Agent used.
+custom settings may also be required dependent upon the actual IoT Agent used. The following is an example of a typical
+`config.js` file:
 
 ```javascript
 config = {
-    logLevel: "DEBUG",
+    logLevel: 'DEBUG',
     contextBroker: {
-        host: "orion",
-        port: "1026",
+        host: 'orion',
+        port: '1026'
     },
     server: {
         port: 4041,
-        host: "0.0.0.0",
+        host: '0.0.0.0'
     },
     deviceRegistry: {
-        type: "memory",
+        type: 'memory'
     },
-    service: "openiot",
-    subservice: "/",
-    providerUrl: "http://iot-agent:4041",
-    defaultType: "Thing",
+    service: 'openiot',
+    subservice: '/',
+    providerUrl: 'http://iot-agent:4041',
+    defaultType: 'Thing'
 };
 ```
 
-In this case the context broker is called `orion` and is listening on port `1026`, the IoT Agent can be provisioned by
+In this case the context broker hostname is `orion` and is listening on port `1026`, the IoT Agent can be provisioned by
 sending requests to port `4041` which is also the port used to receive NGSI requests. The IoT Agent is holding the
 device mappings in memory.
 
@@ -38,13 +55,16 @@ and `fiware-service-path=/`. The default `type`for each created entity is `Thing
 shown below. Devices will be registered for a period of one month and the IoT Agent will receive registration callbacks
 at the URL `http://iot-agent:4041`.
 
-All configuration settings can also updated using Docker environment variables.
+All configuration settings can also updated using Docker environment variables. You can find more information about the
+available configuration parameters and environment variables in the [Administration Guide](admin.md).
 
-### Provisioning a Config Group
+## Provisioning a Config Group
 
-Settings which are common to a group of devices can be passed to the IoT Agent using the Config Group API. The
-`fiware-service` and `fiware-service-path` to be used to access the API are defined within the `config.js`. Each config group
-may override values previously defined in the global configuration if necessary.
+Settings which are common to a group of devices can be passed to the IoT Agent using the Config Group API. Each config
+group may override values previously defined in the global configuration if necessary. When using the config group API,
+the `fiware-service` and `fiware-servicepath` headers will define the service and subservice to which the configuration
+will be applied. Additionally, the `apikey` field is used to identify the configuration group. An example of a basic
+config group is shown below:
 
 ```bash
 curl -iX POST \
@@ -58,20 +78,29 @@ curl -iX POST \
      "apikey":      "4jggokgpepnvsb2uv4s40d59ov",
      "cbHost":     "http://orion:1026",
      "entity_type": "Device",
-     "resource":    "/iot/d",
+     "resource":    "/iot/json",
+     "attributes": [
+       { "object_id": "t", "name": "temperature", "type": "Number" }
+     ]
    }
  ]
 }'
 ```
 
 In this case an `apiKey` for identifying devices has been created and all interactions to the path `/iot/d` which
 present this `apiKey` will be created as entities of `type=Device` rather than using the configuration default of
-`type=Thing`. The config group would usual hold additional attribute mappings, commands and common static attributes as
-well.
+`type=Thing`.
+
+Additionaly, the group has defined an attribute mapping for a measurement `t` to be renamed to `temperature` when
+receiving data from devices.
 
-### Provisioning an Individual Device
+The config group would usual hold additional attribute mappings, commands and common static attributes as well.
 
-Settings which are specific to an individual device can be passed to the IoT Agent using the Device API
+## Provisioning an Individual Device
+
+Settings which are specific to an individual device can be passed to the IoT Agent using the Device API. The
+configuration provided in the Device API will override any settings defined in the Config Group API and the global
+configuration as well. An example of a basic device configuration is shown below:
 
 ```bash
 curl -iX POST \
@@ -86,7 +115,7 @@ curl -iX POST \
      "entity_name": "urn:ngsi-ld:Motion:001",
      "entity_type": "Motion",
      "attributes": [
-       { "object_id": "c", "name": "count", "type": "Integer" }
+       { "object_id": "c", "name": "count", "type": "Number" }
      ],
      "static_attributes": [
        { "name":"refStore", "type": "Relationship", "value": "urn:ngsi-ld:Store:001"}
@@ -97,54 +126,79 @@ curl -iX POST \
 '
 ```
 
+The device `motion001` has been provisioned to persist data to the Context Broker as an entity of `type=Motion` (instead
+of the default `type=Thing`). The destination entity is identified by the `entity_name` field, which is set to
+`urn:ngsi-ld:Motion:001`. The device has a single attribute mapping for a measurement `c` to be renamed to `count`,
+additionally to one defined in the group mapping (`temperature`). The device also has a static attribute `refStore`
+which is a relationship to the entity `urn:ngsi-ld:Store:001`.
+
 This information is combined with the common config group information whenever a request is received at the South port
 of the IoT Agent and used to create or update the relevant entity in the Context Broker.
 
-#### Receiving a measure from a known Device
+## Receiving measures from devices
 
-For example, imagine we are using the Ultralight IoT Agent and the following request is sent to the South port:
+In order to see the complete process from provisioning the groups and devices to receiving measures, we will show how a
+device can send a measure to the IoT Agent. In this case, we will use the IoTA JSON as an example, using the HTTP
+transport protocol. To reproduce the measure sending, you can use the following `curl` commands.
+
+The device measures are sent to the South port of the IoT Agent which is listening in the port `7896`.
+
+### Receiving a measure from a known Device
+
+In this case, the device has been provisioned previously. We will use the `motion001` device defined in the previous
+example. To simulate the device sending a measure, the following request is sent to the South port:
 
 ```bash
 curl -iX POST \
-  'http://localhost:7896/iot/d?k=4jggokgpepnvsb2uv4s40d59ov&i=motion001' \
-  -H 'Content-Type: text/plain' \
-  -d 'c|1'
+  'http://localhost:7896/iot/json?k=4jggokgpepnvsb2uv4s40d59ov&i=motion001' \
+  -H 'Content-Type: application/json' \
+  -d '{"t":23,"c":1}'
 ```
 
 The IoT Agent South port is listening to the path defined in the config group, and the API key is recognized to match.
 Because the `device_id` is also recognized, the provisioned device configuration is used and its settings are combined
-with the config group. A mapping has been found to rename the `c` measurement to `count` - the following context entity
-is created in the context broker:
+with the config group.
+
+Mapping has been found to rename the `c` measurement to `count` and the `t` measurement to `temperature`. The following
+context entity is created in the context broker:
 
 ```json
 {
     "id": "urn:ngsi-ld:Motion:001",
     "type": "Motion",
-    "count": { "value": "1", "type": "Integer" },
+    "temperature": { "value": "23", "type": "Number" },
+    "count": { "value": "1", "type": "Number" },
     "refStore": { "value": "urn:ngsi-ld:Store:001", "type": "Relationship" }
 }
 ```
 
-#### Receiving a measure from an anonymous Device
+### Receiving a measure from an anonymous Device
+
+When receiving a measure, it is not necessary to have the device provisioned. In this case, the IoT Agent will use the
+config group configuration to create the device and the entity. This process is called "autoprovision".
 
-For example, imagine we are using the Ultralight IoT Agent and a request from an anonymous, unprovisioned device is sent
-to the South port:
+Take as an example the following request from an anonymous device:
 
 ```bash
 curl -iX POST \
-  'http://localhost:7896/iot/d?k=4jggokgpepnvsb2uv4s40d59ov&i=temp001' \
-  -H 'Content-Type: text/plain' \
-  -d 't|1'
+  'http://localhost:7896/iot/json?k=4jggokgpepnvsb2uv4s40d59ov&i=dev001' \
+  -H 'Content-Type: application/json' \
+  -d '{"t":13,"c":4}'
 ```
 
 The IoT Agent South port is listen to the path defined in the config group, and the API key is recognized to match, so
-the config group configuration will be used. No mappings will be made for the Entity `id` or the attribute names and
-the following entity will be created:
+the config group configuration will be used. No device has been provisioned with the `device_id=dev001`, so the IoT
+Agent will only use the config group configuration.
+
+A new entity will be created in the Context Broker with the `id` `Device:dev001` and the `type` `Device`. Only the `t`
+measurement will be mapped to the `temperature` attribute, as defined in the config group. The remaining measurements
+will be created as attributes with the same name. The following context entity will be created in the context broker:
 
 ```json
 {
-    "id": "temp001",
+    "id": "Device:dev001",
     "type": "Device",
-    "t": { "value": "1", "type": "Number" }
+    "temperature": { "value": "13", "type": "Number" },
+    "c": { "value": "4", "type": "Number" }
 }
 ```