Dynamically running Azure Quickstart Templates using PowerShell and GitHub REST API

You may be familiar with Microsoft’s Azure Quickstart Templates in GitHub: https://github.com/Azure/azure-quickstart-templates

I was looking for a way to run these in a dynamic fashion, without hard coding any values. This was the plan:

    1.  Using GitHub's REST API, pull list of ARM templates available from https://github.com/Azure/azure-quickstart-templates/tree/master/quickstarts
    2.  Open PowerShell Gridview to display all enumerated templates and allow for a JSON template to be selected
    3.  Pull a list of parameters from the chosen JSON template
    4.  Prompt in shell for the values for those parameters and store those into a hashtable
    5.  Finally, execute the deployment with the template & hashtable containing the parameters

Usage:

• Copy and paste the script shown below into a PowerShell editor such as VSCode, PowerShell ISE, etc.
• Run it.
• A GridView will pop up.
• Select a top level template.
• Continue selecting through recursively until you reach a path that contains an azuredeploy.json file.
• Select the azuredeploy.json and click OK in the GridView window.

• Provide values for the parameters:
  • Note that the script looks for the word ‘password’ in the property name, and if so, stores that particular input as a SecureString in the hashtable.

• Note that the script will show you the Default value from the JSON parameters.  If in doubt, simply copy and paste it into the input field, as seen below:

• A look at a completed Hashtable containing values for all the parameters:

Name                           Value                                                                                                              
----                           -----                                                                                                              
location                       resourceGroup().location                                                                                           
ubuntuOSVersion                Ubuntu-2004                                                                                                        
virtualNetworkName             vNet                                                                                                               
dnsLabelPrefix                 testing                                                                                                            
authenticationType             password                                                                                                           
vmSize                         Standard_D2s_v3                                                                                                    
adminPasswordOrKey             System.Security.SecureString                                                                                       
networkSecurityGroupName       SecGroupNet                                                                                                        
adminUsername                  administrator                                                                                                      
subnetName                                                                                                                                        
securityType                   TrustedLaunch                                                                                                      
vmName                         simpleLinuxVM                 

• You will now be prompted for a Resource Group to be used as a target for the deployment. If you have multiple Subscriptions, remember to use Set-AzContext to focus on the targeted Subscription.
• Finally, the template and the parameters provided will be sent to the New-AzResourceGroupDeployment for deployment.

PowerShell script:

.SYNOPSIS
    Dynamically run Azure Quickstart Templates using PowerShell and GitHub REST API.

.NOTES
    Author: Randy@HumbleSystems.online
    Date:   
        20230802 v1
#>

# .1 Provide root value to start with
    $TreeUI = "https://api.github.com/repos/Azure/azure-quickstart-templates/contents/quickstarts?ref=master"

# .2 Execute and store results from URI
    $RestResult = Invoke-RestMethod -Uri $TreeUI

# .3 Dynamically go through the folders until an azuredeploy.json file is selected:
    $JsonURI = $null
    while ($JsonURI.Name -ne "azuredeploy.json") {
        $JsonURI = $RestResult | Out-GridView -PassThru -Title "Continue to select items until an azuredeploy.json file is selected."
        $RestResult = Invoke-RestMethod -Uri $JsonURI.Url
    }

# Download azuredeploy.json to grab parameters, which will show all possible parameters and not just mandatory ones.
    $JSONParamsFromURI = Invoke-RestMethod -Method Get -Uri $JsonURI.download_url

# Optionally, use the parameters from azuredeploy.parameters.json.  Only the mandatory required fields are prompted for, as opposed to azuredeploy.json - which contains all possible parameters.
    # $JsonParamsURI = $JsonURI.download_url -replace "azuredeploy.json","azuredeploy.parameters.json"
    # $JSONParamsFromURI = Invoke-RestMethod -Method Get -Uri $JsonParamsURI

# Ask for and store values in a hashtable dynamically based on NoteProperties from the json.  
    $ParamsHash = New-Object HashTable
    $JSONParamsFromURI.parameters | Get-Member -MemberType NoteProperty | foreach {
        if ($_.Name -like "*password*") {
            $ParamsHash.Add(`
                $($_.Name),`
                (`
                    ConvertTo-SecureString -AsPlainText -Force `
                    (Read-Host -Prompt "`nProvide value (converted to SecureString) for $($_.Name).`nDescription:  $($JSONParamsFromURI.parameters.$($_.Name).metadata.Description)`nDefault:  $($JSONParamsFromURI.parameters.$($_.Name).defaultValue)`n")) `
                )
        }
        else {
            $ParamsHash.Add($($_.Name), (Read-Host -Prompt "`nProvide value for $($_.Name).`nDescription:  $($JSONParamsFromURI.parameters.$($_.Name).metadata.Description)`nDefault:  $($JSONParamsFromURI.parameters.$($_.Name).defaultValue)`n"))
        }
    }

# 3 AND, Deploy it
    $RGName = (Get-AzResourceGroup | Out-GridView -PassThru -Title "Select target resource group for deployment").ResourceGroupName
    New-AzResourceGroupDeployment -ResourceGroupName $RGName -TemplateUri $JsonURI.download_url -TemplateParameterObject $ParamsHash #-WhatIf