Azure Function V3 .Net Core

Question

Hello,
i just upgraded my azure function V1 to V3(Core), I am getting some problem with connection string.
Here is function sample

   [FunctionName("Function1")]  
        public static void Run([IoTHubTrigger("messages/events", Connection = "ConnectionStrings:IoTHubEndpoint")] EventData message, ILogger log)  
        {  
            log.LogInformation($"C# IoT Hub trigger function processed a message: {Encoding.UTF8.GetString(message.EventBody.ToArray())}");  
        }  

I am Getting this error

Here is local.settings.json file.
{
"IsEncrypted": false,
"Values": {
"AzureWebJobsStorage": "UseDevelopmentStorage=true",
"FUNCTIONS_WORKER_RUNTIME": "dotnet",
},
"ConnectionStrings": {
"IoTHubEndpoint": "mystring"
}
}

Getting this string from here

Someone guide me please what i am doing wrong here ?

Thank you so much for your response.

Answer 1

Hi, I tried your code on a v3 function and that worked for me.

Looking on your error looks like your connection string is not correct.

If you copy from here

Notice a trigger need a path to a hub. that means you need to replace the "mystring" in ("IoTHubEndpoint": "mystring") with the whole value of the endpoint

that will look like this (don't forget the EntityPath). Look like your error is complaining about the EntityPath bit:

Endpoint=sb://iothub-ns-xxxx-17640743-b3xxx6c.servicebus.windows.net/;SharedAccessKeyName=iothubowner;SharedAccessKey=oxxxyU2B0Hcxm9d9aS5EbkxxxXM8/8teIGuro=;EntityPath=myotakl990

That error is common for sender code. if you add the full connection string including the path you should see that error . for sender with 2 params, one is the entity path and the other is the conn string without the path.

Answer 2

Hello @Hassan Shabbir ,

I just created a test project based on your information (using VS Code and azure function template).

I was able to run it locally and ingest messages from an IoT Hub:

I used this configuration:

{  
  "IsEncrypted": false,  
  "Values": {  
    "AzureWebJobsStorage": "UseDevelopmentStorage=true",  
    "FUNCTIONS_WORKER_RUNTIME": "dotnet"  
  },  
  "ConnectionStrings": {  
    "IoTHubEndpoint": "Endpoint=sb://iothub-ns-storage-ro-17651825-0b2daeb2a7.servicebus.windows.net/;SharedAccessKeyName=iothubowner;SharedAccessKey=[a sas key]=;EntityPath=storage-route-test-ih"  
  }  
}  

With this function:

using IoTHubTrigger = Microsoft.Azure.WebJobs.EventHubTriggerAttribute;  
  
using Microsoft.Azure.WebJobs;  
using Microsoft.Azure.WebJobs.Host;  
using Microsoft.Azure.EventHubs;  
using System.Text;  
using System.Net.Http;  
using Microsoft.Extensions.Logging;  
  
namespace Company.Function  
{  
    public static class IoTHub_EventHub1  
    {  
        private static HttpClient client = new HttpClient();  
  
        [FunctionName("IoTHub_EventHub1")]  
        public static void Run([IoTHubTrigger("messages/events", Connection = "IoTHubEndpoint", ConsumerGroup = "fa")]EventData message, ILogger log)  
        {  
            log.LogInformation($"C# IoT Hub trigger function processed a message: {Encoding.UTF8.GetString(message.Body.Array)}");  
        }  
    }  
}  

The only thing a changed was adding a consumer group.

I'm not sure why you get that error message. As you can see, it works for me.

Full code example available at GitHub.

Answer 3

@Hassan Shabbir ,

Thanks for reaching out to Q&A.

The connection string should be passed in this way Connection = "IoTHubEndpoint". Create a name value pair in the local.settings.json file with the name "IoTHubEndpoint" and connection string obtained from the portal as value.

I hope this helps!

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