Rediger

Quickstart: Route custom events to web endpoint with Azure CLI and Event Grid

In this quickstart, you use the Azure CLI to create a custom topic in Azure Event Grid, subscribe to the custom topic, and trigger a sample event to view the result.

Typically, you send events to an endpoint that processes the event data and takes actions. However, to simplify this quickstart, you send sample events to a web app that collects and displays the messages. When you finish, you see the event data in the web app, as shown in the following image:

Screenshot showing the Event Grid Viewer sample with a sample event.

If you don't have an Azure account, create a free account before you begin.

Prerequisites

  • This quickstart requires version 2.0.70 or later of the Azure CLI. If you use Azure Cloud Shell, the latest version is already installed.
  • If you're new to Azure Event Grid, see What's Azure Event Grid for an overview of the service before you start this quickstart.

Create a resource group

Event Grid topics are Azure resources that you must place in an Azure resource group. The resource group is a logical collection into which you deploy and manage Azure resources.

Create a resource group with the az group create command. The following example creates a resource group named gridResourceGroup in the westus2 location. Change the name of the resource group and the location if you want.

az group create --name gridResourceGroup --location westus2

Enable the Event Grid resource provider

  1. If this is the first time you're using Event Grid in your Azure subscription, you might need to register the Event Grid resource provider. Run the following command to register the provider:

    az provider register --namespace Microsoft.EventGrid

  2. It might take a moment for the registration to finish. To check the status, run the following command:

    az provider show --namespace Microsoft.EventGrid --query "registrationState"

    When registrationState is Registered, you're ready to continue.

Create a custom topic

An Event Grid topic provides a user-defined endpoint that you post your events to. The following example creates the custom topic in your resource group by using Bash in Azure Cloud Shell. Replace <your-topic-name> with a unique name for your topic. The custom topic name must be unique because it's part of the Domain Name System (DNS) entry. Also, it must be between 3-50 characters and contain only values a-z, A-Z, 0-9, and "-"

  1. Copy the following command, specify a name for the topic, and select Enter to run the command.

    topicname=<your-topic-name>

  2. Use the az eventgrid topic create command to create a custom topic.

    az eventgrid topic create --name $topicname -l westus2 -g gridResourceGroup

Create a message endpoint

Before you subscribe to the custom topic, create the endpoint for the event message. Typically, the endpoint takes actions based on the event data. To simplify this quickstart, deploy a prebuilt web app that shows the event messages. The deployed solution includes an App Service plan, an App Service web app, and source code from GitHub.

  1. Copy the following command, specify a name for the web app (Event Grid Viewer sample), and select Enter to run the command. Replace <your-site-name> with a unique name for your web app. The web app name must be unique because it's part of the DNS entry.

    sitename=<your-site-name>

  2. Run the az deployment group create to deploy the web app by using an Azure Resource Manager template.

    az deployment group create \
  --resource-group gridResourceGroup \
  --template-uri "https://raw.githubusercontent.com/Azure-Samples/azure-event-grid-viewer/main/azuredeploy.json" \
  --parameters siteName=$sitename hostingPlanName=viewerhost

The deployment might take a few minutes to complete. After the deployment succeeds, view your web app to make sure it's running. In a web browser, navigate to: https://<your-site-name>.azurewebsites.net

You should see the site with no messages displayed.

Subscribe to a custom topic

You subscribe to an Event Grid topic to tell Event Grid which events you want to track and where to send those events. The following example subscribes to the custom topic you created, and passes the URL from your web app as the endpoint for event notification.

The endpoint for your web app must include the suffix /api/updates/.

  1. Copy the following command, replace $sitename with the name of the web app you created in the previous step, and select Enter to run the command.

    endpoint=https://$sitename.azurewebsites.net/api/updates

  2. Run the following command to get the resource ID of the topic you created.

    topicresourceid=$(az eventgrid topic show --resource-group gridResourceGroup --name $topicname --query "id" --output tsv)

  3. Run the following command to create a subscription to the custom topic using the endpoint.

    az eventgrid event-subscription create \
  --source-resource-id $topicresourceid \
  --name demoViewerSub \
  --endpoint $endpoint

    View your web app again, and notice that a subscription validation event has been sent to it. Select the eye icon to expand the event data. Event Grid sends the validation event so the endpoint can verify that it wants to receive event data. The web app includes code to validate the subscription.

    Screenshot showing the Event Grid Viewer sample with a subscription validation event.

Send an event to your custom topic

Let's trigger an event to see how Event Grid distributes the message to your endpoint. First, get the URL and key for the custom topic.

endpoint=$(az eventgrid topic show --name $topicname -g gridResourceGroup --query "endpoint" --output tsv)
key=$(az eventgrid topic key list --name $topicname -g gridResourceGroup --query "key1" --output tsv)

To simplify this quickstart, use sample event data to send to the custom topic. Typically, an application or Azure service sends the event data. The following example creates sample event data:

event='[ {"id": "'"$RANDOM"'", "eventType": "recordInserted", "subject": "myapp/vehicles/motorcycles", "eventTime": "'`date +%Y-%m-%dT%H:%M:%S%z`'", "data":{ "make": "Ducati", "model": "Monster"},"dataVersion": "1.0"} ]'

The data element of the JSON is the payload of your event. Any well-formed JSON can go in this field. You can also use the subject field for advanced routing and filtering.

cURL is a utility that sends HTTP requests. In this quickstart, use cURL to send the event to the topic.

curl -X POST -H "aeg-sas-key: $key" -d "$event" $endpoint

You triggered the event, and Event Grid sent the message to the endpoint you configured when subscribing. View your web app to see the event you just sent.

[{
  "id": "1807",
  "eventType": "recordInserted",
  "subject": "myapp/vehicles/motorcycles",
  "eventTime": "2017-08-10T21:03:07+00:00",
  "data": {
    "make": "Ducati",
    "model": "Monster"
  },
  "dataVersion": "1.0",
  "metadataVersion": "1",
  "topic": "/subscriptions/{subscription-id}/resourceGroups/{resource-group}/providers/Microsoft.EventGrid/topics/{topic}"
}]

Clean up resources

If you plan to continue working with this event or the event viewer app, don't clean up the resources you created in this quickstart. Otherwise, use the following command to delete the resources you created in this quickstart.

az group delete --name gridResourceGroup --yes --no-wait

Related content

Now that you know how to create topics and event subscriptions, learn more about what Event Grid can help you do:

To learn about publishing events to and consuming events from Event Grid in different programming languages, see the following samples:

  • Last updated on