nieomylnieja/deviceservice

deviceservice's Issues

Add device

• provide endpoint POST /devices that accepts payload

   {
   Name: string,
   Interval: int,
   Value: float
  }
  

• Interval > 0

• Name cannot be empty

• endpoint returns Device object

 {
  Id: int,
  Name: string,
  Interval: int,
  Value: float
 }

• example request: http :8000/devices name="test name" interval:=-1
• example request2: http :8000/devices < device1.json where
  device1.json is a file that looks like:

  {"name": "test name",
   "interval": -1
  }
  

Implement measurements persistence

Create new implementation of MeasurementsWriter that saves measurements in InfluxDB.

• for every value received, write it to influxDB as influx's value, deviceId as Influx's tag and with timestamp = now() and precision set to second. values should be stored in influx's measurement called deviceValues, database called mydb
  • in case write fails just log it
• InfluxDB address should be read from environment variable. If InfluxDB is not reachable during deviceService start it should panic

Example test InfluxDB query: SELECT * FROM deviceValues group by deviceId

Get device by Id

• implement endpoint GET /devices/:id that returns device object
• it should return 400 if id was not a number
• it should return 404 if device was not found
• it should return 500 in case there was an error in DAO

Persist devices in MongoDB

• on POST /devices store device in MongoDB
• on GET /devices/:id read device from db
• on GET /devices read all devices from db

---

• use MongoDB version 3.6 or higher (the newest is fine as well)
• use official mongodb golang driver (https://github.com/mongodb/mongo-go-driver)
• initialize mongoDB connection in main.go

GET all devices

• implement endpoint GET /devices that returns list of all devices
• endpoint has to accept size and limit HTTP query parameters:
  • limit - limits length of returned. Default limit = 100. If limit == 0, ignore page (even if provided) and return all devices
  • page - tells which page should be returned. Page starts from 0. Default page = 0.
• it should return 400 if page or limit are not integer or less than zero
• it should return empty json array ([]) when there were no devices
• it should return 500 in case there was an error in DAO

Example request: http :8000/devices page==2 limit==4

Communicate Ticker and Writer using RabbitMQ

Ticker service should push new dataPoints/measurements on RabbitMQ topic (instead of golang channel).

• topic name: measurements
• routing key should be set to device id

Writer service should accept measurements on the RabbitMQ topic. It should listen to measurements from all devices.

Implement TickerService

• Ticker service, when started, reads all devices from. For every device:
  • create new time.Ticker that ticks in intervals read from device
  • on tick, send new measurement to chan<- Measurement, setting value and id read from device
• Add endpoint POST /start that starts the Ticker

---

• Implement MeasurementsWriter
• MeasurementsWriter, when started, waits for measurements from <-chan Measurement
• on new measurement it just prints it out to the console

---

type Measurement struct {
  Id int
  Value float64
}