serviceBusTrigger is not registered error in Azure Functions for Javascript

Question

I'm trying to create a Function that is triggered when a message becomes available in an Azure Service Bus subscription. I followed the brief example from the official docs.

Running the app locally via func host start leads to the following error: "ServiceBusTriggerJS: The binding type 'serviceBusTrigger' is not registered. Please ensure the type is correct and the binding extension is installed."

My setup:

package.json contains the azure node module: "azure": "^2.2.1-preview". Node version is 8.11.

function.json is as in the example:

{
  "disabled": false,
  "bindings": [
    {
      "topicName": "myTopic",
      "subscriptionName": "mySubscription",
      "connection": "MyServiceBus",
      "name": "myQueueItem",
      "type": "serviceBusTrigger",
      "direction": "in"
    }
  ]
}

local.settings.json contains connection strings to the Service Bus and a storage account that is necessary for running locally:

{
  "IsEncrypted": false,
  "Values": {
    "AzureWebJobsStorage": "DefaultEndpointsProtocol=https;AccountName=...",
    "MyServiceBus": "Endpoint=sb://...servicebus.windows.net/;SharedAccessKeyName=RootManageSharedAccessKey;SharedAccessKey=..."
  }
}

index.js is the same as the example, too:

module.exports = function (context, myQueueItem) {
    context.log('JavaScript queue trigger function processed work item', myQueueItem);
    context.done();
};

---

EDIT: This is similar to this question: The binding type 'serviceBusTrigger' is not registered error in azure functions c# with core tools 2. The problem (and therefore solution) are the same. I find the answer here straight-forward to implement.

Answer 1

You should install the servicebus extension using

func extensions install --package Microsoft.Azure.WebJobs.ServiceBus --version 3.0.0-beta5.

The extension is used to register the servicebus trigger, making the trigger recognized by your local function run time. It is like a complement for the run time, so it doesn't matter what language you use.

Everything works on my side(js function), feel free to ask if you have further questions.