Click, Validate, Deploy: Mastering ARM Template Deployment in Azure Portal

Infrastructure as Code (IaC) is not limited to command-line tools. Azure allows you to deploy ARM (Azure Resource Manager) templates directly from the Azure Portal, making it easy to test, validate, and understand templates before moving to full automation.

In this guide, you’ll learn how to deploy an ARM template using the Azure Portal, validate it, provide parameters, and monitor deployment results—step by step.

---

What You’ll Do

• Deploy an ARM template via Azure Portal

• Use the Custom Template Deployment feature

• Provide parameters correctly

• Validate and monitor the deployment

• Understand common errors and fixes

---

Prerequisites

• An active Azure subscription

• An ARM template file (template.json)

• (Optional) Parameters file (parameters.json)

No Azure CLI or PowerShell required.

---

Step 1 — Sign in to Azure Portal

1. Go to 👉 https://portal.azure.com

2. Sign in with your Azure account

Step 2 — Navigate to Custom Template Deployment

1. In the Azure Portal search bar, type Deploy a custom template

2. Select Deploy a custom template

The page below will be displayed. click on "Build your own template

Delete the default page as selected

Step 3 — Choose How to Load the ARM Template

You will see several options:

• Build your own template in the editor ✅ (most common)

• Load a template file

• Load a template from GitHub

• Load a template from a URL

Recommended Option: Load a Template File

1. Click Build your own template in the editor

2. Click Load file

3. Upload your template.json

4. Click Save

Azure will automatically parse and validate the JSON syntax.

for this lab, i have copied my Json file, i will paste it and save

Step 4 — Fill in Deployment Details

After saving the template, you’ll be redirected to the deployment screen.

Complete the following fields:

Subscription: Select your Azure subscription

Resource group:

Choose an existing resource group OR

Click Create new

Region: Choose a region (if required by the template)

Parameters:

Enter values for required parameters (e.g. VM name, admin username, SSH key)

Azure automatically generates input fields based on the parameters defined in your template.

Then click on 'create'

After a successful deployment, click on 'Go to resource'

In the arm-rg, click on the VNet created to ensure the resources created are there

From the VNet created, under settings select subnet

scroll down to Automation tab still on the left pane, click on Export template, the exported template will be displayed as shown below

click on 'download' to download the exported template

Go to your downloads, open the downloaded template with VScode

To redeploy, lets delete the existing resources in azure, go to azure portal, select the resource group

Go to azure portal, search for 'deploy a custom template'

select the deploy a custom template, on the displayed page, click on 'build your own template in the editor'

On the displayed page, click on 'load file'

Select the downloaded file by clicking the 'load file' then click on 'save'

click on 'save'. on the custom deployment page, create a new RG, then 'review and create'

Then 'create'

After a successful deployment, click on 'go to resource'

On the overview page, click on the VNet created

on the settings tab, select 'subnets'

Still under settings, select 'export template' . our exported and redeployed template is displayed as shown.

Don't forget to delete the new -rg created. Select the resource group and click on delete

When Should You Use Portal Deployment?

Azure Portal deployment is ideal when:

• Learning ARM templates

• Testing templates before automation

• Demonstrating IaC concepts to students or teams

• Quickly validating template behavior

For production pipelines, pair ARM templates with:

• Azure CLI

• Azure DevOps

• GitHub Actions

---

Final Thoughts

Deploying ARM templates through the Azure Portal is the simplest entry point into Infrastructure as Code. It helps you understand how Azure interprets templates, validates parameters, and provisions resources—before you automate everything.