Descriptions

we want to build an ’app’ which can listen to a specific ‘storage account’, whenever a new file has been uploaded(we take this an event), this app will be triggered to do sth based on the event.

About Event Grid

Components

Events - What happened, alerts,facts

Event sources - Where the event took place.

Event generator/publisher - e.g. Storage blob

Topics - One of an endpoint where publishers send events.

Event subscriptions - The endpoint or built-in mechanism to route events, sometimes to more than one handler. Subscriptions are also used by handlers to intelligently filter incoming events.

Event handlers - The app or service reacting to the event.(Microsoft built-in service)

Event Grid Subscription - like an agent, connect the event generators and the end points.

Event Grid Domain- An event domain is a management tool for large numbers of Event Grid topics related to the same application

Event Grid Topics

Architecture

About Azure Storage Blob

Azure Blob storage is Microsoft’s object storage solution for the cloud.

ResourceGroup–> Storage Account–> Containers –> Blobs

docmentation

Solution 1: build Azure function

Method 1: using Azure portal(recommended)

How to create storage blob trigger

Azure function bingding event grid

1. Create an Azure Function app using the Azure portal

2. Expand your function app and click the + button next to Functions. If this is the first function in your function app, select In-portal then Continue. Otherwise, go to step three.

3. choose more Template–> Event Grid trigger

4. select Add Event Grid subscription.

5. Create Event Subscription you will see more details about configuring the Event Subscription

Method 2: using Azure cli

prerequisites:

• Install Azure Core Tools version 2.x.
• Install the Azure CLI 2.0 +. az login

1. create a azure function project:

     $func init myApp
     Select a worker runtime: 
     1. dotnet
     2. node
     3. python (preview)
     4. powershell (preview)
     Choose option: 1
     dotnet
   
     Writing /lhome/yxiaoli/Documents/myApp/.vscode/extensions.json
   
   

   Better to chose dotnet…instead of python

2. generate app function:

     $ cd myApp
     $ func new --name EventTrigger
     Select a template: 
     1. QueueTrigger
     2. HttpTrigger
     3. BlobTrigger
     4. TimerTrigger
     5. DurableFunctionsOrchestration
     6. SendGrid
     7. EventHubTrigger
     8. ServiceBusQueueTrigger
     9. ServiceBusTopicTrigger
     10. EventGridTrigger
     11. CosmosDBTrigger
     12. IotHubTrigger
     Choose option: 10
     Function name: EventTrigger
   
     The function "EventTrigger" was created successfully from the "EventGridTrigger" template.
   
   

3. customize your function

4. upload the Function App to Azure:

   $func azure functionapp publish ${your-function-name}
   

Reference

1. using ‘azure.storage.blob’ return BlobBlockList –> BlobBlock(id, )

2. Event Grid concepts

3. blobtrigger vs Event Grid

4. Storage queue vs. service bus

5. [what is event hub](https://hackernoon.com/azure-functions-choosing-between-queues-and-event-hubs-dac4157eee1c

6. comparing messages

7. Logic apps vs. azure functions apps