Backup-AzureResourceGroupInventory

<#
.SYNOPSIS
    Backup-AzureResourceGroupInventory.ps1 - Snapshots a resource group's inventory to JSON.

.DESCRIPTION
    Exports every resource in a resource group (name, type, location, tags) to a
    timestamped JSON file. It is not a full configuration backup, it is a fast
    "what did this look like before I touched it" snapshot to diff against later.

.AUTHOR
    Shehryar Hassan

.EXAMPLE
    .\Backup-AzureResourceGroupInventory.ps1 -ResourceGroupName "rg-prod-weu"
#>

param(
    [Parameter(Mandatory=$true)]
    [string]$ResourceGroupName,

    [Parameter(Mandatory=$false)]
    [string]$OutputPath = ".\rg-inventory-$(Get-Date -Format 'yyyyMMdd-HHmmss').json"
)

Write-Host "=============================================" -ForegroundColor Cyan
Write-Host "  Azure Resource Group Inventory Snapshot" -ForegroundColor Cyan
Write-Host "=============================================" -ForegroundColor Cyan

if (-not (Get-AzContext)) {
    Write-Host "[INFO] Connecting to Azure..." -ForegroundColor Yellow
    Connect-AzAccount | Out-Null
}

$rg = Get-AzResourceGroup -Name $ResourceGroupName -ErrorAction Stop
$resources = Get-AzResource -ResourceGroupName $ResourceGroupName

$snapshot = [PSCustomObject]@{
    ResourceGroup = $ResourceGroupName
    Location      = $rg.Location
    CapturedAt    = (Get-Date).ToString("o")
    ResourceCount = $resources.Count
    Resources     = $resources | Select-Object Name, ResourceType, Location, Tags
}

$snapshot | ConvertTo-Json -Depth 6 | Out-File -FilePath $OutputPath -Encoding utf8

Write-Host "[SUCCESS] $($resources.Count) resource(s) snapshotted to: $OutputPath" -ForegroundColor Green
Write-Host "[INFO] Keep this before any bulk change, it is the fastest way to see exactly what moved." -ForegroundColor Yellow