StreetlightsAPI

Streetlights API Example

This is an example implementation (with minor additions) of the Streetlights API from the asyncapi tutorial.

Running

The example project references the Saunter project directly (for easy debugging), so we need to install the UI assets manually. This requires nodejs/npm, but neither are required when using the nuget package in your project.

Run the sample with dotnet run and then use curl (or similar) to send test requests to the API.

#### Install UI assets

$ cd ~/saunter/src/Saunter.UI
$ npm install

added 106 packages, and audited 107 packages in 2s

1 package is looking for funding
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found 0 vulnerabilities

#### Run the example

$ cd ~/saunter/examples/StreetlightsAPI
$ dotnet run

info: StreetlightsAPI.Program[0] AsyncAPI doc available at: http://localhost:5000/asyncapi/asyncapi.json
info: StreetlightsAPI.Program[0] AsyncAPI UI available at: http://localhost:5000/asyncapi/ui/
info: Microsoft.Hosting.Lifetime[0] Now listening on: http://localhost:5000
info: Microsoft.Hosting.Lifetime[0] Application started. Press Ctrl+C to shut down.
info: Microsoft.Hosting.Lifetime[0] Hosting environment: Production
info: Microsoft.Hosting.Lifetime[0] Content root path: saunter\examples\StreetlightsAPI

#### View the UI in your browser at http://localhost:5000/asyncapi/ui/

#### Get streetlights

$ Invoke-WebRequest 'http://localhost:5000/api/streetlights' | ConvertFrom-Json

id position                lightIntensity
-- --------                --------------
 1 {-36.32032, 175.485986} {}

#### Publish an example light measurement

$ Invoke-WebRequest -Method POST -Uri 'http://localhost:5000/publish/light/measured' -Body '{"id":1, "lumens":400}' -ContentType 'application/json' | Select StatusCode

StatusCode
----------
       200

#### In the logs for the API we should see our message being subscribed & published

StreetlightsAPI.StreetlightsController[0] Received message on publish/light/measured with payload {"Id":1,"Lumens":400,"SentAt":"2021-09-11T00:52:55.4171809+12:00"}
info: Streetlight[0] Publishing message {"Id":1,"Lumens":400,"SentAt":"2021-09-11T00:52:55.4171809+12:00"} to test.mosquitto.org/subscribe/light/measured
      
#### Get the AsyncAPI Schema document

$ Invoke-WebRequest -Method GET -Uri 'http://localhost:5000/asyncapi/asyncapi.json'

The generated asyncapi document is not identical to the AsyncAPI example above as schemas are automatically moved to the components section of the document.

{
  "asyncapi": "2.6.0",
  "info": {
    "title": "Streetlights API",
    "version": "1.0.0",
    "description": "The Smartylighting Streetlights API allows you to remotely manage the city lights.",
    "license": {
      "name": "Apache 2.0",
      "url": "https://www.apache.org/licenses/LICENSE-2.0"
    }
  },
  "servers": {
    "mosquitto": {
      "url": "test.mosquitto.org",
      "protocol": "mqtt"
    },
    "webapi": {
      "url": "localhost:5000",
      "protocol": "http"
    }
  },
  "defaultContentType": "application/json",
  "channels": {
    "publish/light/measured": {
      "servers": [
        "webapi"
      ],
      "publish": {
        "operationId": "MeasureLight",
        "summary": "Inform about environmental lighting conditions for a particular streetlight.",
        "tags": [
          {
            "name": "Light"
          }
        ],
        "bindings": {
          "$ref": "#/components/operationBindings/postBind"
        },
        "message": {
          "$ref": "#/components/messages/lightMeasuredEvent"
        }
      }
    },
    "subscribe/light/measured": {
      "servers": [
        "mosquitto"
      ],
      "subscribe": {
        "operationId": "PublishLightMeasurement",
        "summary": "Subscribe to environmental lighting conditions for a particular streetlight.",
        "tags": [
          {
            "name": "Light"
          }
        ],
        "message": {
          "$ref": "#/components/messages/lightMeasuredEvent"
        }
      },
      "bindings": {
        "$ref": "#/components/channelBindings/amqpDev"
      }
    }
  },
  "components": {
    "schemas": {
      "lightMeasuredEvent": {
        "title": "lightMeasuredEvent",
        "type": "object",
        "properties": {
          "id": {
            "title": "int32",
            "type": "integer",
            "format": "int32"
          },
          "lumens": {
            "title": "int32",
            "type": "integer",
            "format": "int32"
          },
          "sentAt": {
            "title": "dateTime",
            "type": "string",
            "format": "dateTime"
          }
        },
        "nullable": true
      },
      "int32": {
        "title": "int32",
        "type": "integer",
        "format": "int32"
      },
      "dateTime": {
        "title": "dateTime",
        "type": "string",
        "format": "dateTime"
      }
    },
    "messages": {
      "lightMeasuredEvent": {
        "payload": {
          "$ref": "#/components/schemas/lightMeasuredEvent"
        },
        "name": "lightMeasuredEvent",
        "title": "lightMeasuredEvent"
      }
    },
    "channelBindings": {
      "amqpDev": {
        "amqp": {
          "is": "queue"
        }
      }
    },
    "operationBindings": {
      "postBind": {
        "http": {
          "type": "response",
          "method": "POST"
        }
      }
    }
  }
}