Azure WebJobs EventGrid client library for .NET - version 3.3.1

This extension provides functionality for receiving Event Grid webhook calls in Azure Functions, allowing you to easily write functions that respond to any event published to Event Grid.

Getting started

Install the package

Install the Event Grid extension with NuGet:

dotnet add package Microsoft.Azure.WebJobs.Extensions.EventGrid

Prerequisites

You must have an Azure subscription and an Azure resource group with a custom Event Grid topic or domain. Follow this step-by-step tutorial to register the Event Grid resource provider and create Event Grid topics using the Azure portal. There is a similar tutorial using Azure CLI.

Authenticate the Client

In order for the extension publish events, you will need the endpoint of the Event Grid topic and a credential, which can be created using the topic's access key.

You can find the endpoint for your Event Grid topic either in the Azure Portal or by using the Azure CLI snippet below.

az eventgrid topic show --name <your-resource-name> --resource-group <your-resource-group-name> --query "endpoint"

The access key can also be found through the portal, or by using the Azure CLI snippet below:

az eventgrid topic key list --name <your-resource-name> --resource-group <your-resource-group-name> --query "key1"

Key concepts

Using Event Grid output binding

Please follow the binding tutorial to learn about using this extension for publishing EventGrid events.

Using Event Grid trigger

Please follow the tutorial to learn about triggering an Azure Function when an event is published.

Examples

Functions that uses Event Grid output binding

If you are using the EventGrid schema for your topic, you can output EventGridEvents.

public static class EventGridEventBindingFunction
{
    [FunctionName("EventGridEventBindingFunction")]
    public static async Task<IActionResult> RunAsync(
        [HttpTrigger(AuthorizationLevel.Anonymous, "get", "post", Route = null)] HttpRequest req,
        [EventGrid(TopicEndpointUri = "EventGridEndpoint", TopicKeySetting = "EventGridKey")] IAsyncCollector<EventGridEvent> eventCollector)
    {
        EventGridEvent e = new EventGridEvent(await req.ReadAsStringAsync(), "IncomingRequest", "IncomingRequest", "1.0.0");
        await eventCollector.AddAsync(e);
        return new OkResult();
    }
}

If you are using the CloudEvent schema for your topic, you can output CloudEvents.

public static class CloudEventBindingFunction
{
    [FunctionName("CloudEventBindingFunction")]
    public static async Task<IActionResult> RunAsync(
        [HttpTrigger(AuthorizationLevel.Anonymous, "get", "post", Route = null)] HttpRequest req,
        [EventGrid(TopicEndpointUri = "EventGridEndpoint", TopicKeySetting = "EventGridKey")] IAsyncCollector<CloudEvent> eventCollector)
    {
        CloudEvent e = new CloudEvent("IncomingRequest", "IncomingRequest", await req.ReadAsStringAsync());
        await eventCollector.AddAsync(e);
        return new OkResult();
    }
}

It is also possible to use Azure Identity with the output binding. To do so, set the Connection property to the name of your app setting that contains your Event Grid Topic endpoint along with a set of optional Identity information that is described in detail here. When setting the Connection property, the TopicEndpointUri and TopicKeySetting properties should NOT be set.

public static class CloudEventOutputBindingWithIdentityFunction
{
    [FunctionName("CloudEventOutputBindingWithIdentityFunction")]
    public static async Task<IActionResult> RunAsync(
        [HttpTrigger(AuthorizationLevel.Anonymous, "get", "post", Route = null)] HttpRequest req,
        [EventGrid(Connection = "MyConnection")] IAsyncCollector<CloudEvent> eventCollector)
    {
        CloudEvent e = new CloudEvent("IncomingRequest", "IncomingRequest", await req.ReadAsStringAsync());
        await eventCollector.AddAsync(e);
        return new OkResult();
    }
}

For local development, use the local.settings.json file to store the connection information:

{
  "Values": {
    "myConnection__topicEndpointUri": "{topicEndpointUri}"
  }
}

When deployed, use the application settings to store this information.

You can also output a string or JObject and the extension will attempt to parse into the correct strongly typed event.

Functions that uses Event Grid trigger

You can also create a function that will be executed whenever an event is delivered to your topic. Depending on the schema you have selected for your Azure Function event subscription, you can bind to either EventGridEvent or CloudEvent:

public static class EventGridEventTriggerFunction
{
    [FunctionName("EventGridEventTriggerFunction")]
    public static void Run(
        ILogger logger,
        [EventGridTrigger] EventGridEvent e)
    {
        logger.LogInformation("Event received {type} {subject}", e.EventType, e.Subject);
    }
}

And if your subscription is configured with the CloudEvent schema:

public static class CloudEventTriggerFunction
{
    [FunctionName("CloudEventTriggerFunction")]
    public static void Run(
        ILogger logger,
        [EventGridTrigger] CloudEvent e)
    {
        logger.LogInformation("Event received {type} {subject}", e.Type, e.Subject);
    }
}

It is also possible to bind to an array of events. This is useful if you have batching enabled for your Event Grid Subscription.

public static class EventGridEventBatchTriggerFunction
{
    [FunctionName("EventGridEventBatchTriggerFunction")]
    public static void Run(
        ILogger logger,
        [EventGridTrigger] EventGridEvent[] events)
    {
        foreach (EventGridEvent eventGridEvent in events)
        {
            logger.LogInformation("Event received {type} {subject}", eventGridEvent.EventType, eventGridEvent.Subject);
        }
    }
}

Similarly, for subscriptions configured with the CloudEvent schema:

public static class CloudEventBatchTriggerFunction
{
    [FunctionName("CloudEventBatchTriggerFunction")]
    public static void Run(
        ILogger logger,
        [EventGridTrigger] CloudEvent[] events)
    {
        foreach (CloudEvent cloudEvent in events)
        {
            logger.LogInformation("Event received {type} {subject}", cloudEvent.Type, cloudEvent.Subject);
        }
    }
}

Troubleshooting

Please refer to Monitor Azure Functions for troubleshooting guidance.

Next steps

Read the introduction to Azure Function or creating an Azure Function guide.

Contributing

See our CONTRIBUTING.md for details on building, testing, and contributing to this library.

This project welcomes contributions and suggestions. Most contributions require you to agree to a Contributor License Agreement (CLA) declaring that you have the right to, and actually do, grant us the rights to use your contribution. For details, visit cla.microsoft.com.

This project has adopted the Microsoft Open Source Code of Conduct. For more information see the Code of Conduct FAQ or contact opencode@microsoft.com with any additional questions or comments.