PowerShell Script to retrieve Azure Usage and Cost/Pricing through the Usage Details API

Get-AzureUsageCost.ps1

# Licensed under the MIT license.
# Copyright (C) 2022 Helsedirektoratet

# Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the
# "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, 
# publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so,
# subject to the following conditions:

# The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE
# FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
# WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

<#
.SYNOPSIS
The script returns monthly data from the Usage Details API https://docs.microsoft.com/en-us/rest/api/consumption/usage-details/list
and generates excel sheets using the ImportExcel module. The API call is designed to retrieve consumption for a month.
In turn, both raw data and monthly grouped data is grouped by the 'project' tag, resource group, and resource name. The raw script output assumes the tags
'cost-center', 'project' and 'environment' are in place. Edit the script to suit your own environment
This script was inspired by Kristofer Liljeblad's script https://gist.github.com/krist00fer/9e8ff18ac4f22863d41aec0753ebdac4
.EXAMPLE

$env:ClientSecret = 'my_clientsecretin_in_rawtext"

Get consumption data for the previous billing period (default)
Get-AzureUsageCost.ps1 -ClientSecret $env:ClientSecret

Get consumption data for a specified billing period
Get-AzureUsageCost.ps1 -ClientSecret $env:ClientSecret -YearMonth = 201903
#>

param(
    [string]$YearMonth = (Get-Date).AddMonths(-1).ToString("yyyyMM"),
    [Parameter(Mandatory)]
    [string]$ClientSecret,
    [switch]$RunInPipeline
)

# Replace the following configuration settings
$tenantId = "yourtenanthere.onmicrosoft.com"
$clientId = "xxxxxxxxxxxxxxxxx"
$subscriptionIds = @(
    "xxx-yyy"
    "yyy-xxx"
)

if ($RunInPipeline) {
    Write-Host "Installing required modules as you are running in context of a pipeline..." -ForegroundColor Yellow
    Install-Module ImportExcel -Force
    Import-Module ImportExcel -Force
}

# Login

$loginUri = "https://login.microsoftonline.com/$tenantId/oauth2/token?api-version=1.0"

$body = @{
    grant_type    = "client_credentials"
    resource      = "https://management.core.windows.net/"
    client_id     = $clientId
    client_secret = $ClientSecret
}

Write-Host "Authenticating" 

$loginResponse = Invoke-RestMethod $loginUri -Method Post -Body $body
$authorization = $loginResponse.token_type + ' ' + $loginResponse.access_token
# Use the same header in all the calls, so save authorization in a header dictionary

$headers = @{
    authorization = $authorization
}
$ErrorActionPreference = "Continue"

# Usage Details API

$Date = (Get-Date -AsUTC).ToString("yyyy-MM-dd-HH.mm.ssZ")
$billingPeriod = $YearMonth + "01"
$excelFile = "./output/costoverview-$billingPeriod.xlsx"
$billingString = "/providers/Microsoft.Billing/billingPeriods/$billingPeriod/providers"
$usageRows = New-Object System.Collections.ArrayList

foreach ($subId in $subscriptionIds) {
    $usageUri = "https://management.azure.com/subscriptions/$subId$billingString/Microsoft.Consumption/usageDetails?`$expand=meterDetails&api-version=2021-10-01"

    Write-Host "Querying Azure Usage API for subscription $subId"

    do {
        Write-Host "."
        $usageResult = Invoke-RestMethod $usageUri -Headers $headers -ContentType "application/json"

        foreach ($usageRow in $usageResult.value) {
            $usageRows.Add($usageRow) > $null
        }

        $usageUri = $usageResult.nextLink

        # If there's a continuation, then call API again
    } while ($usageUri)
}

# Fine tune result
$usageRows = $usageRows | Sort-Object -Property { $_.properties.date }, { $_.properties.tags.project }, { $_.properties.resourceName }

$reportResult = $usageRows | Select-Object @{ N = 'DateTime'; E = { $_.properties.date } }, @{ N = 'ResourceName'; E = { $_.properties.resourceName } }, @{ N = 'ResourceGroup'; E = { $_.properties.resourceGroup } }, `
@{ N = 'CostCenter'; E = { $_.tags."cost-center" } }, @{ N = 'Project'; E = { $_.tags."project" } }, @{ N = 'Environment'; E = { $_.tags."environment" } }, @{ N = 'ResourceLocation'; E = { $_.properties.resourceLocation } }, 
@{ N = 'ConsumedService'; E = { $_.properties.consumedService } }, `
@{ N = 'Product'; E = { $_.properties.product } }, @{ N = 'Quantity'; E = { $_.properties.quantity } }, @{ N = 'UnitOfMeasure'; E = { $_.properties.meterDetails.unitOfMeasure } }, `
@{ N = 'UnitPrice'; E = { $_.properties.UnitPrice } }, @{ N = 'Cost'; E = { $_.properties.Cost } }, @{ N = 'Currency'; E = { $_.properties.billingCurrency } }, `
@{ N = 'PartNumber'; E = { $_.properties.partNumber } }, @{ N = 'MeterId'; E = { $_.properties.meterId } }

# Group by project tag + month

$projectGroup = $reportresult | Select-Object Project, Cost |  Group-Object Project | ForEach-Object {
    New-Object -Type PSObject -Property @{
        'BillingPeriod' = $YearMonth
        'Project'       = $_.Group | Select-Object -Expand Project -First 1
        'NOK'           = ($_.Group | Measure-Object Cost -Sum).Sum
    }
}  | Sort-Object NOK -Descending

# Group by rg + month

$rgGroup = $reportresult | Select-Object resourceGroup, Cost, ResourceLocation |  Group-Object resourceGroup | ForEach-Object {
    New-Object -Type PSObject -Property @{
        'BillingPeriod'    = $YearMonth
        'ResourceGroup'    = $_.Group | Select-Object -Expand ResourceGroup -First 1
        'NOK'              = ($_.Group | Measure-Object Cost -Sum).Sum
        'ResourceLocation' = $_.Group | Select-Object -Expand ResourceLocation -First 1
    }
}  | Sort-Object NOK -Descending

# Group by resourceName + month

$resGrouping = $reportresult | Select-Object ResourceName, ResourceGroup, ResourceLocation, ConsumedService, Cost |  Group-Object ResourceName | ForEach-Object {
    New-Object -Type PSObject -Property @{
        'BillingPeriod'    = $YearMonth
        'ResourceName'     = $_.Group | Select-Object -Expand ResourceName -First 1
        'NOK'              = ($_.Group | Measure-Object Cost -Sum).Sum
        'ServiceNamespace' = $_.Group  | Select-Object -Expand ConsumedService -First 1
        'ResourceLocation' = $_.Group  | Select-Object -Expand ResourceLocation -First 1
        'ResourceGroup'    = $_.Group  | Select-Object -Expand ResourceGroup -First 1
    }
} | Sort-Object NOK -Descending

# Export to File

$xlParams = @{WorkSheet = $ws; Bold = $true; FontSize = 16 }
$rawDataSheet = "Raw consumption data"
$groupingSheet = "By project tag"
$groupingSheet2 = "By resource group"
$groupingSheet3 = "By resourcename"

$excel2 = $projectGroup | Export-Excel -WorksheetName $groupingSheet -Path $ExcelFile -AutoSize -TableName Table1 -StartRow 15 -PassThru
$ws = $excel2.Workbook.Worksheets[$groupingSheet]
Set-Format -Range A1  -Value "Script run at: $($Date)" @xlParams -Worksheet $ws
Set-Format -Range A4  -Value "The script covers all subscriptions" @xlParams -Worksheet $ws
Set-Format -Range A13  -Value "Cost grouped by project tag" @xlParams -Worksheet $ws
Close-ExcelPackage $excel2

$excel0 = $rgGroup | Export-Excel -WorksheetName $groupingSheet2 -Path $ExcelFile -AutoSize -TableName Table2 -StartRow 15 -PassThru
$ws = $excel0.Workbook.Worksheets[$groupingSheet2]
Set-Format -Range A13  -Value "Cost grouped by resource group" @xlParams -Worksheet $ws
Close-ExcelPackage $excel0

$excel3 = $resGrouping | Export-Excel -WorksheetName $groupingSheet3 -Path $ExcelFile -AutoSize -TableName Table3 -StartRow 15 -PassThru
$ws = $excel3.Workbook.Worksheets[$groupingSheet3]
Set-Format -Range A13  -Value "Cost grouped by resource name" @xlParams -Worksheet $ws
Close-ExcelPackage $excel3

$excel1 = $reportResult | Export-Excel -WorksheetName $rawDataSheet -Path $ExcelFile -AutoSize -TableName Table4 -StartRow 15 -PassThru
$ws = $excel1.Workbook.Worksheets[$rawDataSheet]
Close-ExcelPackage $excel1

Can anyone tell me where I can get the ClientID and Client Secrete? do I have to create an Application Registration on Azure for this?

Can anyone tell me where I can get the ClientID and Client Secrete? do I have to create an Application Registration on Azure for this?

You will have to create an App Registration and provide it with billing reader access on each subscription in the Azure Tenant.