Is there a way to make an Azure function triggerable by multiple Service Bus event queues? For example, if there is a function which logic is valid for multiple cases(event start, event end- each inserted into a different Service Bus queue) and I want to reuse it for these events can I subscribe to both of them in the Service Bus from the same function?
I was looking for an answer to this question, but so far everywhere I checked it seems to be impossible.
Azure Functions can be triggered by a single source queue or subscription. If you'd like to consolidate multiple sources to serve as a trigger for a single function, you could forward messages to a single entity (let's assume a queue) and configure Function to be triggered by messages in that queue. Azure Service Bus support Auto-Forwarding natively.
Note that there cannot be more than 3 hops and you cannot necessarily know what the source was if message was forwarded from a queue. For subscriptions, there's a possible workaround to stamp messages.
If your goal is to simply reuse code, what about refactoring that Function to create a class which is then used in multiple functions.
If your goal is implementing events aggregation, you could probably create an Azure Durable Function Workflow that would do a fan-in on multiple Events.
Excerpt from https://github.com/Azure/azure-functions-durable-extension/issues/166:
Processing Azure blobs in hourly batches.
New blob notifications are sent to a trigger function using Event Grid trigger.
The event grid trigger uses the singleton pattern to create a single orchestration instance of a well-known name and raises an event to the instance containing the blob payload(s).
To protect against race conditions in instance creation, the event grid trigger is configured as a singleton using SingletonAttribute.
Blob payloads are aggregated into a List and sent to another function for processing - in this case, aggregated into a single per-batch output blob.
A Durable Timer is used to determine the one-hour time boundaries.
