Can I add DeviceID in path while storing data from Azure Stream Analytics to Blob storage

Question

I have Data incoming from Different devices to IoT hub from there using Stream Analytics to process it and store it in blob storage. I know we can add {date}{time} we add in the path according to needed format, in that path can we add deviceId too.

example : For 2018/10/30/01 ( Date/month/day/hour) Can add /deviceId in that path while storing to blob

Answer 1

The following is an example of workaround for your case. It's based on the using an azure function (HttpTrigger) for output ASA job to append a data to the specific blob storage in the push manner. Note, that the following workaround using the Max batch count for delivering events to the azure function value 1 (one telemetry data at the time).

ASA job query:

SELECT
  System.Timestamp as [time], * 
INTO outAF
FROM 
  iot TIMESTAMP BY time

Azure Function (HttpTrigger):

run.csx

#r "Newtonsoft.Json"
#r "Microsoft.WindowsAzure.Storage"

using System.Net;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Extensions.Primitives;
using Microsoft.WindowsAzure.Storage.Blob;
using Newtonsoft.Json;
using Newtonsoft.Json.Linq;

public static async Task<IActionResult> Run(string body, CloudBlobContainer blobContainer, ILogger log)
{
    log.LogInformation($"{body}");

    var jtoken = JToken.Parse(body);
    var jobject = jtoken is JArray ? jtoken.SingleOrDefault<JToken>() : jtoken;
    if(jobject != null)
    {
        var jtext = jobject.ToString(Formatting.None);
        var data = JsonConvert.DeserializeAnonymousType(jtext, new {IoTHub = new { ConnectionDeviceId = ""}});        
        var blobName = $"{DateTime.UtcNow.ToString("yyyy/MM/dd/hh")}/{data.IoTHub.ConnectionDeviceId}";  
        var blob = blobContainer.GetAppendBlobReference(blobName);
        if(!await blob.ExistsAsync())
        {
            await blob.CreateOrReplaceAsync();
        }
        await blob.AppendTextAsync(jtext + "\r\n");
    }
return new NoContentResult();

}

function.json

    {
      "bindings": [
       {
           "authLevel": "function",
           "name": "body",
           "type": "httpTrigger",
           "direction": "in",
           "methods": [
             "get",
             "post"
             ]
      },
      {
          "name": "blobContainer",
          "type": "blob",
          "path": "myContainer",
          "connection": "mySTORAGE",
          "direction": "out"
      },
      {
          "name": "$return",
          "type": "http",
          "direction": "out"
      }
      ]
 }