Azure Event Grid Domain Creation: Overcoming AZ CLI's TLS Parameter Limitations with Workaround
Introduction: The Intersection of Security Policies and DevOps Automation In the modern cloud landscape, organizations increasingly enforce strict security requirements through platform policies. One common requirement is mandating latest TLS versions for example TLS 1.2 across all deployed resources to protect data in transit. While this is an excellent security practice, it can sometimes conflict with the available configuration options in deployment tools, particularly in the Azure CLI. This blog explores a specific scenario that many Azure DevOps teams encounter: how to deploy an Azure Event Grid domain when your organization has a custom policy requiring latest version considering TLS 1.2, but the Azure CLI command doesn't provide a parameter to configure this setting. The Problem: Understanding the Gap Between Policy and Tooling What Is Azure Event Grid? Azure Event Grid is a serverless event routing service that enables event-driven architectures. It manages the routing of events from various sources (like Azure services, custom applications, or SaaS products) to different handlers such as Azure Functions, Logic Apps, or custom webhooks. An Event Grid domain provides a custom topic endpoint that can receive events from multiple sources, offering a way to organize and manage events at scale. The Policy Requirement: Many organizations implement Azure Policy to enforce security standards across their cloud infrastructure. A common policy might look like this: { "policyRule": { "if": { "allOf": [ { "field": "type", "equals": "Microsoft.EventGrid/domains" }, { "anyOf": [ { "field": "Microsoft.EventGrid/domains/minimumTlsVersion", "exists": false }, { "field": "Microsoft.EventGrid/domains/minimumTlsVersion", "notEquals": "1.2" } ] } ] }, "then": { "effect": "deny" } } } This policy blocks the creation of any Event Grid domain that doesn't explicitly set TLS 1.2 as the minimum TLS version. The CLI Limitation: Now, let's examine the Azure CLI command to create an Event Grid domain: az eventgrid domain | Microsoft Learn TLS property is unrecognized with the latest version of AZ CLI version. Current Status of This Limitation: It's worth noting that this limitation has been recognized by the Azure team. There is an official GitHub feature request tracking this issue, which you can find at => Please add TLS support while creation of Azure Event Grid domain through CLI · Issue #31278 · Azure/azure-cli Before implementing this workaround described in this article, I recommend checking the current status of this feature request. The Azure CLI is continuously evolving, and by the time you're reading this, the limitation might have been addressed. However, as of April 2025, this remains a known limitation in the Azure CLI, necessitating the alternative approach outlined below. Why This Matters: This limitation becomes particularly problematic in CI/CD pipelines or Infrastructure as Code (IaC) scenarios where you want to automate the deployment of Event Grid domain resources. Workaround: You can utilize below ARM template and deploy it through AZ CLI in your deployment pipeline as below: Working ARM template: { "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#", "contentVersion": "1.0.0.0", "parameters": { "domainName": { "type": "string", "metadata": { "description": "Name of the Event Grid Domain" } }, "location": { "type": "string", "defaultValue": "[resourceGroup().location]", "metadata": { "description": "Azure region for the domain" } } }, "resources": [ { "type": "Microsoft.EventGrid/domains", "apiVersion": "2025-02-15", "name": "[parameters('domainName')]", "location": "[parameters('location')]", "properties": { "minimumTlsVersionAllowed": "1.2" } } ] } Please note I've used latest API version from below official Microsoft documentation : Microsoft.EventGrid/domains - Bicep, ARM template & Terraform AzAPI reference | Microsoft Learn Working AZ CLI command: az deployment group create --resource-group <rg> --template-file <armtemplate.json> --parameters domainName=<event grid domain name> You can store this ARM template in your configuration directory with replacement for Azure CLI command. It explicitly sets TLS 1.2 for Event Grid domains, ensuring security compliance where the CLI lacks this parameter. For example: az deployment group create --resource-group <rg> --template-file ./config/<armtemplate.json> --parameters domainName=<event grid domain name> Disclaimer: The sample scripts provided in this article are provided AS IS without warranty of any kind. The author is not responsible for any issues, damages, or problems that may arise from using these scripts. Users should thoroughly test any implementation in their environment before deploying to production. Azure services and APIs may change over time, which could affect the functionality of the provided scripts. Always refer to the latest Azure documentation for the most up-to-date information. Thanks for reading this blog! I hope you've found this workaround valuable for addressing the Event Grid domain TLS parameter limitation in Azure CLI. 😊Azure Event Grid CLI Identity Gaps & Workarounds with Python REST and ARM Templates
Azure Event Grid has become a cornerstone service for building event-driven architectures in the cloud. It provides a scalable event routing service that enables reactive programming patterns, connecting event sources to event handlers seamlessly. However, when working with Event Grid through the Azure CLI, developers often encounter a significant limitation: the inability to configure system-assigned managed identities using CLI commands. In this blog post, I'll explore this limitation and provide practical workarounds using Python REST API calls and ARM templates with CLI to ensure your Event Grid deployments can leverage the security benefits of managed identities without being blocked by tooling constraints. Problem Statement: Unlike many other Azure resources that support the --identity or ---assign-identity parameter for enabling system-assigned managed identities, Event Grid's CLI commands lack this capability while creating event subscription for system topic at the moment. This means that while the Azure Portal and other methods support managed identities for Event Grid, you can't configure them directly through the CLI in case of system topic event subscriptions For example you can add managed identity for delivery through portal but not through AZ CLI: If you try to use the following CLI command: az eventgrid system-topic event-subscription create \ --name my-sub \ --system-topic-name my-topic \ --resource-group my-rg \ --endpoint <EH resource id> --endpoint-type eventhub \ --identity systemassigned You'll run into a limitation: The --identity flag is not supported or unrecognized for system topic subscriptions in Azure CLI. Also, --delivery-identity is in preview and under development Current Status of This Limitation: It's worth noting that this limitation has been recognized by the Azure team. There is an official GitHub feature request tracking this issue, which you can find at Use managed identity to command creates an event subscription for an event grid system topic · Issue #26910 · Azure/azure-cli. Before implementing any of the workarounds described in this article, I recommend checking the current status of this feature request. The Azure CLI is continuously evolving, and by the time you're reading this, the limitation might have been addressed. However, as of April 2025, this remains a known limitation in the Azure CLI, necessitating the alternative approaches outlined below. Why This Matters: This limitation becomes particularly problematic in CI/CD pipelines or Infrastructure as Code (IaC) scenarios where you want to automate the deployment of Event Grid resources with managed identities. Solution 1: Using Azure REST API with Python request library: The first approach to overcome this limitation is to use the Azure REST API with Python. This provides the most granular control over your Event Grid resources and allows you to enable system-assigned managed identities programmatically. System Topic Event Subscriptions - Create Or Update - REST API (Azure Event Grid) | Microsoft Learn You can retrieve Azure Entra token using below CLI command: az account get-access-token Sample working code & payload: import requests import json subscription_id = <> resource_group = <> system_topic_name = <> event_subscription_name = <> event_hub_resource_id = <> access_token = <> url = f"https://management.azure.com/subscriptions/{subscription_id}/resourceGroups/{resource_group}/providers/Microsoft.EventGrid/systemTopics/{system_topic_name}/eventSubscriptions/{event_subscription_name}?api-version=2024-12-15-preview" payload = { "identity": { "type": "SystemAssigned" }, "properties": { "topic": "/subscriptions/<>/resourceGroups/<>/providers/Microsoft.EventGrid/systemTopics/<>", "filter": { "includedEventTypes": [ "Microsoft.Storage.BlobCreated", "Microsoft.Storage.BlobDeleted" ], "advancedFilters": [], "enableAdvancedFilteringOnArrays": True }, "labels": [], "eventDeliverySchema": "EventGridSchema", "deliveryWithResourceIdentity": { "identity": { "type": "SystemAssigned" }, "destination": { "endpointType": "EventHub", "properties": { "resourceId": "/subscriptions/<>/resourceGroups/rg-sch/providers/Microsoft.EventHub/namespaces/<>/eventhubs/<>", "deliveryAttributeMappings": [ { "name": "test", "type": "Static", "properties": { "value": "test", "isSecret": False, "sourceField": "" } }, { "name": "id", "type": "Dynamic", "properties": { "value": "abc", "isSecret": False, "sourceField": "data.key" } } ] } } } } } headers = { "Authorization": f"Bearer {access_token}", "Content-Type": "application/json" } response = requests.put(url, headers=headers, data=json.dumps(payload)) if response.status_code in [200, 201]: print("Event subscription created successfully!") Remember that these tokens are sensitive security credentials, so handle them with appropriate care. They should never be exposed in logs, shared repositories, or other insecure locations. Solution 2: Using ARM Templates & deploying it through CLI Another solution is to use Azure Resource Manager (ARM) templates, which fully support system-assigned managed identities for Event Grid. This approach works well in existing IaC workflows. Microsoft.EventGrid/systemTopics/eventSubscriptions - Bicep, ARM template & Terraform AzAPI reference | Microsoft Learn Here's a sample ARM template that creates an Event Grid topic with a system-assigned managed identity: { "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#", "contentVersion": "1.0.0.0", "parameters": { "systemTopicName": { "type": "string", "metadata": { "description": "Name of the existing system topic" } }, "eventSubscriptionName": { "type": "string", "metadata": { "description": "Name of the event subscription to create" } }, "eventHubResourceId": { "type": "string", "metadata": { "description": "Resource ID of the Event Hub to send events to" } }, "includedEventType": { "type": "string", "defaultValue": "Microsoft.Storage.BlobCreated", "metadata": { "description": "Event type to filter on" } } }, "resources": [ { "type": "Microsoft.EventGrid/systemTopics/eventSubscriptions", "apiVersion": "2024-06-01-preview", "name": "[format('{0}/{1}', parameters('systemTopicName'), parameters('eventSubscriptionName'))]", "identity": { "type": "SystemAssigned" }, "properties": { "deliveryWithResourceIdentity": { "destination": { "endpointType": "EventHub", "properties": { "resourceId": "[parameters('eventHubResourceId')]" } }, "identity": { "type": "SystemAssigned" } }, "eventDeliverySchema": "EventGridSchema", "filter": { "includedEventTypes": [ "[parameters('includedEventType')]" ] } } } ] } How to deploy via Azure CLI: az deployment group create \ --resource-group <your-resource-group> \ --template-file eventgridarmtemplate.json \ --parameters \ systemTopicName=<system-topic-name> \ eventSubscriptionName=<event-subscription-name> \ eventHubResourceId="/subscriptions/<sub>/resourceGroups/<rg>/providers/Microsoft.EventHub/namespaces/<namespace>/eventhubs/<hub>" Disclaimer The sample scripts provided in this article are provided AS IS without warranty of any kind. The author is not responsible for any issues, damages, or problems that may arise from using these scripts. Users should thoroughly test any implementation in their environment before deploying to production. Azure services and APIs may change over time, which could affect the functionality of the provided scripts. Always refer to the latest Azure documentation for the most up-to-date information. Thanks for reading this blog! I hope you've found these workarounds valuable for addressing the Event Grid identity parameter limitation in Azure CLI. 😊Liam Hampton code.talks Session Resources
London Reactor Meetup | AI Edition September 2023 Hey Everyone! Thanks for joining my session at code.talks! Here you can find the resources that I shared and my contact details. Resources: Azure Developer CLI September 2023 Release Getting started with the Azure Developer CLI Azure Developer Templates GitHub Developer Tools (Copilot, Codespaces etc.) Microsoft for Startups Founders Hub Benefits Other Relatable resources: Microsoft Reactor Events Microsoft Reactor Meetup Contact the speakers: Liam Hampton, Senior Cloud Advocate @ Microsoft Twitter (X) LinkedIn
