Add environment vars

Author: PatAltimore

articles/iot-operations/connect-to-cloud/tutorial-connect-event-grid.md

@@ -7,7 +7,7 @@ ms.subservice: mq
 ms.custom: devx-track-azurecli
 ms.author: patricka
 ms.topic: tutorial
-ms.date: 11/15/2023
+ms.date: 02/28/2024
 
 #CustomerIntent: As an operator, I want to configure IoT MQ to bridge to Azure Event Grid MQTT broker PaaS so that I can process my IoT data at the edge and in the cloud.
 ---
@@ -22,12 +22,46 @@ In this tutorial, you learn how to configure IoT MQ for bi-directional MQTT brid
 
 * [Deploy Azure IoT Operations](../get-started/quickstart-deploy.md)
 
+## Set environment variables
+
+
+Sign in with Azure CLI:
+
+```azurecli
+az login
+```
+
+Set environment variables for the rest of the setup. Replace values in `<>` with valid values or names of your choice. A new Azure Event Grid namespace and topic space are created in your Azure subscription based on the names you provide:
+
+```azurecli
+# For this tutorial, the steps assume the IoT Operations cluster and the Event Grid
+#  are in the same subscription, resource group, and location.
+
+# Name of the resource group of Azure Event Grid and IoT Operations cluster 
+export RESOURCE_GROUP=<RESOURCE_GROUP_NAME>
+
+# Azure region of Azure Event Grid and IoT Operations cluster
+export LOCATION=<LOCATION>
+
+# Name of the Azure Event Grid namespace
+export EVENT_GRID_NAMESPACE=<EVENT_GRID_NAMESPACE>
+
+# Name of the Arc-enabled IoT Operations cluster 
+export CLUSTER_NAME=<CLUSTER_NAME>
+
+# Subscription ID of Azure Event Grid and IoT Operations cluster
+export SUBSCRIPTION_ID=<SUBSCRIPTION_ID>
+```
+
 ## Create Event Grid namespace with MQTT broker enabled
 
-[Create Event Grid namespace](../../event-grid/create-view-manage-namespaces.md) with Azure CLI. Replace `<EG_NAME>`, `<RESOURCE_GROUP>`, and `<LOCATION>` with your own values. The location should be the same as the one you used to deploy Azure IoT Operations.
+[Create Event Grid namespace](../../event-grid/create-view-manage-namespaces.md) with Azure CLI. The location should be the same as the one you used to deploy Azure IoT Operations.
 
 ```azurecli
-az eventgrid namespace create -n <EG_NAME> -g <RESOURCE_GROUP> --location <LOCATION> --topic-spaces-configuration "{state:Enabled,maximumClientSessionsPerAuthenticationName:3}"
+az eventgrid namespace create --namespace-name $EVENT_GRID_NAMESPACE \
+--resource-group $RESOURCE_GROUP \
+--location $LOCATION \
+--topic-spaces-configuration "{state:Enabled,maximumClientSessionsPerAuthenticationName:3}"
 ```
 
 By setting the `topic-spaces-configuration`, this command creates a namespace with:
@@ -39,20 +73,29 @@ The max client sessions option allows IoT MQ to spawn multiple instances and sti
 
 ## Create a topic space
 
-In the Event Grid namespace, create a topic space named `tutorial` with a topic template `telemetry/#`. Replace `<EG_NAME>` and `<RESOURCE_GROUP>` with your own values.
+In the Event Grid namespace, create a topic space named `tutorial` with a topic template `telemetry/#`.
 
 ```azurecli
-az eventgrid namespace topic-space create -g <RESOURCE_GROUP> --namespace-name <EG_NAME> --name tutorial --topic-templates "telemetry/#"
+az eventgrid namespace topic-space create --resource-group $RESOURCE_GROUP \
+--namespace-name $EVENT_GRID_NAMESPACE \
+--name tutorial \
+--topic-templates "telemetry/#"
 ```
 
 By using the `#` wildcard in the topic template, you can publish to any topic under the `telemetry` topic space. For example, `telemetry/temperature` or `telemetry/humidity`.
 
 ## Give IoT MQ access to the Event Grid topic space
 
-Using `az k8s-extension show`, find the principal ID for the Azure IoT MQ Arc extension.
+Using `az k8s-extension show`, find the principal ID for the Azure IoT MQ Arc extension. The command stores the principal ID in a variable for later use.
 
 ```azurecli
-az k8s-extension show --resource-group <RESOURCE_GROUP> --cluster-name <CLUSTER_NAME> --name mq --cluster-type connectedClusters --query identity.principalId -o tsv
+export PRINCIPAL_ID=$(az k8s-extension show --resource-group $RESOURCE_GROUP \
+--cluster-name $CLUSTER_NAME \
+--name mq \
+--cluster-type connectedClusters \
+--query identity.principalId -o tsv)
+
+echo $PRINCIPAL_ID
 ```
 
 Take note of the output value for `identity.principalId`, which is a GUID value with the following format: