Azure Functions support EventGrid Trigger. By deleting a blob, we send a deletion event through Azure Event Grid. Many of Azure’s services can publish events to an Event Grid topic. The name pattern can be a filter or binding expression. The name of the variable that represents the blob in function code. See the example and configuration sections for more detail. Refer to the trigger example for details. Azure Functions support EventGrid Trigger. You can use Event Grid with Azure Functions. For example, use Event Grid to instantly trigger a serverless function to run image analysis each time a new photo is added to a blob storage container. For more information, see Azure Function Event Grid Trigger Local Debugging. The following example shows a Functions 1.x C# function that binds to JObject: The following example shows a trigger binding in a function.json file and a C# script function that uses the binding. You see the site but no events have been posted to it yet. However, currently there is no built-in support to create custom topic events. You can specify a blob name pattern in the path property in function.json or in the BlobTrigger attribute constructor. When you subscribe to an Event Grid topic, be sure to use the system key. The following example shows a C# function that writes a log when a blob is added or updated in the samples-workitems container. I used a function app deployed with run from package and made the Event Grid Topic creation dependent on the function to provide enough time for the app to deploy prior to the validation occurring. In the blob storage container 5 million images are created—each one triggering the Function through Event Grid. Here's an example of the response that provides the system key: You can get the master key for your function app from the Function app settings tab in the portal. However, I can’t find explicit document until now. Together, the Event Grid trigger and Azure Functions give you a lot of power, and this solution has many applications. Azure Functions stores blob receipts in a container named azure-webjobs-hosts in the Azure storage account for your function app (defined by the app setting AzureWebJobsStorage). Instrument the Azure Function to generate custom metrics. For information on setup and configuration details, see the overview. When a request shows up in your web app, copy the request body. Post to the URL of your Event Grid trigger function. Minimizing latency: If your function app is on the Consumption plan, there can be up to a 10-minute delay in processing new blobs if a function app has gone idle. In the previous part of the series we saw how to improve the reliability of responding to new blobs. These values have the same semantics as the Cloud​Blob type. The Event Grid event is made available to the function via a parameter named eventGridEvent, as shown in the following PowerShell example. In my case, I was using the WebHook endpoint type. For functions that you develop in the Azure portal with the Event Grid trigger, select Integration then choose the Event Grid Trigger and select Create Event Grid subscription. The function writes a log when a blob is added or updated in the samples-workitems container. There are no constructor parameters or properties to set in the EventGridTrigger attribute. You can use the following parameter types for the triggering blob: 1 Requires "inout" binding direction in function.json or FileAccess.ReadWrite in a C# class library. The following example triggers only on .png files: To look for curly braces in file names, escape the braces by using two braces. Alternatively, you can send an HTTP PUT to specify the key value yourself. For explanations of the common and event-specific properties, see Event properties in the Event Grid documentation. This means that Azure Data Lake Storage Gen2 can now generate events that can be consumed by Event Grid and routed to subscribers with webhooks, Azure Event Hubs, Azure Functions, and Logic Apps as endpoints. However, I can’t find explicit document until now. I can see that the Event Grid System Topic appears to be configured for the correct storage account according to the overview page in the Azure Portal: How to get metadata of deleted blob in Event Grid Trigger Azure Function? Location. In the Java functions runtime library, use the EventGridTrigger annotation on parameters whose value would come from EventGrid. For information on setup and configuration details, see the overview. For example, a function app with three blob-triggered functions and the default settings would have a maximum per-VM concurrency of 3*24 = 72 function invocations. When the function is triggered, you will use logic to get data from the triggered event and insert that into a new row within Azure table storage in the destination storage account. Currently Event Grid is preview. Event Grid is deeply integrated into Azure. Recommendation: Though there is an inbuilt blob trigger function, it is best to set up an Event Grid subscription and trigger with Azure Functions when it comes to processing the blobs. The @BlobTrigger attribute is used to give you access to the blob that triggered the function. For example, if you created a blob storage subscription, upload or delete a blob. The Event Grid instance is available via the parameter configured in the function.json file's name property, typed as func.EventGridEvent. An Azure Function could then subscribe to this event and be used to resize and compress the image. Locally Debugging an Event Grid Triggered Azure Function with Postman 18 DEC 2018 • 4 mins read tl;dr Just like you’d expect but the trick is to add this header (which took me a long time to track down in the docs): aeg-event-type = Notification. Then use a queue trigger instead of a blob trigger to process the blob. Event Grid is great for connecting events that come from azure resources (or custom resources) to things like Azure Functions or Logic Apps. I'm investigating the webhooks / event triggers available for Azure Storage. See the Image resize with Event Grid tutorial of an Event Grid example. The CSV file is then deleted after a succesful upload. For Azure Blob Storage, if you want to ensure that the Microsoft.Storage.BlobCreated event is triggered only when a Block Blob is completely committed, filter the event for the CopyBlob, PutBlob, and PutBlockList REST API calls. The name of an app setting that contains the Storage connection string to use for this binding. For example, the following C# script and JavaScript examples log the path to the triggering blob, including the container: The Azure Functions runtime ensures that no blob trigger function gets called more than once for the same new or updated blob. The following screenshots show the headers and request body in Postman: The Event Grid trigger function executes and shows logs similar to the following example: Required - the variable name used in function code for the parameter that receives the event data. For more information on how to use this web app to see the events generated by an Azure Event Grid Topic, see Azure Event Grid Viewer. The deployed solution includes an App Service plan, an App Service web app, and source code from GitHub.