This example demonstrates how to create and deploy an Azure Function which has Service Bus Queue as its trigger event using Serverless Framework.

• This app will create and deploy an Azure Function which would be triggered when a message would arrive in a Service Bus Queue.
• This app also exposes an http endpoint to send a sample message to service bus queue.

The serverless.yml would define an Azure Function handler with its trigger event as Service Bus and by providing necessary details about the service bus - queue name and connection string. Whenever a message would arrive in defined service bus queue, an azure function would be invoked and sent message would be processed in its handler.

To send a sample message on defined service bus queue, serverless.yml declares one sample http POST end point. This can be used to send a message on defined service bus queue.

npm install in this directory to download the modules from package.json.

The serverless offline --stage dev command will let you try and test your azure function locally.

Before running this command -

1. You need to create a service bus queue on Azure Portal and provide the connection string in serverless.yml as an environment variable and refer this environment variable name in "connection" hook.

# in serverless.yml
provider:
  environment:
	  VARIABLE_SBUS_CONNECTION_STRING: 'Endpoint=sb://.......'
....
....
....

events:
  - serviceBus:
	x-azure-settings:
		queueName: '<YourServiceBusQueueName>'
		accessRights: manage
		connection: VARIABLE_SBUS_CONNECTION_STRING

2. Define Service Bus details - Connection string and queuename- in .env.dev file. This connection string & queuename would be used in serviceBusMessageSender.ts file to send sample message to service bus queue.

# in .env.dev file

SERVICEBUS_CS='Endpoint=sb://.....'
SERVICEBUS_QUEUE_NAME=<YourServiceBusQueueName>

Once this is done, run the command serverless offline --stage dev.

The console would show the output message which should look something like this -

Application started. Press Ctrl+C to shut down.

Functions:

        sendMessage: [POST] http://localhost:7071/api/v3/send

        sampleHandler: serviceBusTrigger

For detailed output, run func with --verbose flag.
[2020-10-30T07:54:23.803] Worker process started and initialized.

1. Provide the appropriate Service Bus details in serverless.yml & .env.dev file as mentioned in step #2.

2. Provide the desired azure resourceGroup, subscriptionId,region and stage values in serverless.yml to deploy the app on Azure.

Once above steps are done, run the command serverless deploy --env dev.

The console would show the output message which should look something like this -

Serverless: Finished uploading blob
Serverless: -> Function package uploaded successfully
Serverless: Deployed serverless functions:
Serverless: -> Function App not ready. Retry 0 of 30...
Serverless: -> Function App not ready. Retry 1 of 30...
Serverless: -> Function App not ready. Retry 2 of 30...
Serverless: -> sendMessage: [POST] sls-<region>-dev-service-bus-trigger-example.azurewebsites.net/api/api/v3/send

1. Send a sample message on service bus using ../api/api/v3/send end point:

Send a POST request on ../api/api/v3/send endpoint with following payload -

{
    "id": 101,
    "name": "AnyName",
    "gender": "Male/Female",
    "age": 30
}

When the service bus receives the above sample message, it will invoke another azure function - sampleHandler and it shall print the above payload on console. The console would show the output message which should look something like this -

[2020-10-30T08:20:07.998] Executed 'Functions.sendMessage' (Succeeded, Id=f08ed5e7-5bd2-4c7c-8054-e23cad3dbb82, Duration=317ms)
[2020-10-30T08:20:11.001] Executing 'Functions.sampleHandler' (Reason='New ServiceBus message detected on 'myqueuename'.', Id=abbb78d1-a19c-4ea7-b8a7-3ae6e9c6e66d)
[2020-10-30T08:20:11.005] Trigger Details: MessageId: 83840f43a8824791bc2c9624d68ea1c2, DeliveryCount: 2, EnqueuedTime: 10/30/2020 8:20:10 AM, LockedUntil: 10/30/2020 8:20:40 AM, SessionId: (null)
[2020-10-30T08:20:11.023] [2020-10-30T13:50:11.022+05:30][INFO][src\controller\triggerFunctionController.ts]: Azure function has been trigged with message {"id":10,"name":"Kurshit","gender":"Male","age":27} in service bus
[2020-10-30T08:20:11.026] Executed 'Functions.sampleHandler' (Succeeded, Id=abbb78d1-a19c-4ea7-b8a7-3ae6e9c6e66d, Duration=39ms)