Using MS Azure API cost report with PowerShell

Question

I've been trying to extract usage cost using Azure Cost Management API, i ran the API through Postman to test the URI's before injecting them into the powershell script. this is the POST method I used:

POST https://management.azure.com/subscriptions/0000000-0000-0000-0000-00000000/providers/Microsoft.CostManagement/generateCostDetailsReport?api-version=2022-10-01

{
  "metric": "ActualCost",
  "timePeriod": {
    "start": "2020-03-01",
    "end": "2020-03-15"
  }
}

I used this Microsoft API link as a reference : Generate Cost Details Report - Create Operation

according to Microsoft the result (cost management report) should be in an another URI that comes in this POST response within the Headers (Location), see first screenshot:

the link highlighted should be the one that I will be using to get the results for a signle subscriptions and it worked perfectly fine using Postman. However, now I want to use both methods (POST and GET) and rund them in a PS script that goes through subscriptions and generate/download the file automatically. this is the script that I was able to come up with :

# Step 1: Get mandatory parameters from the user
$startDate = Read-Host "Enter the start date (YYYY-MM-DD):"
$endDate = Read-Host "Enter the end date (YYYY-MM-DD):"

# Step 2: Connect to Azure and get subscriptions
Connect-AzAccount

$subscriptions = Get-AzSubscription | Select-Object -ExpandProperty SubscriptionId

# Step 3: Process each subscription
foreach ($subscriptionId in $subscriptions) {
    # Generate cost details report
    $generateReportUri = "https://management.azure.com/subscriptions/$subscriptionId/providers/Microsoft.CostManagement/generateCostDetailsReport?api-version=2022-10-01"

    $reportRequest = @{
        metric = "ActualCost"
        timePeriod = @{
            start = $startDate
            end = $endDate
        }
    }

    $reportResponse = Invoke-RestMethod -Uri $generateReportUri -Method Post -Body ($reportRequest | ConvertTo-Json) -Headers @{ "Authorization" = "Bearer $((Get-AzAccessToken).Token)" }

    # Get usage report URI
    $usageGet1Uri = $reportResponse.Headers.Location

    # Download and rename the usage report file
    $usageReport = Invoke-RestMethod -Uri $usageGet1Uri -Method Get -Headers @{ "Authorization" = "Bearer $((Get-AzAccessToken).Token)" }
    $blobLink = $usageReport.Manifest.blobs.blobLink
    $subscriptionName = (Get-AzSubscription -SubscriptionId $subscriptionId).Name
    $fileName = "$subscriptionName.csv"

    Invoke-WebRequest -Uri $blobLink -OutFile $fileName

    Write-Host "Downloaded and renamed usage report for subscription '$subscriptionName' to '$fileName'."
}

I want to make sure that I am getting both Headers.Location from POST method and the BlobLink from the reponse body from GET method, and I don't know whether I called them right in the script or not. This is the error that I got when I tried to run it on my environment:

Invoke-RestMethod : Cannot validate argument on parameter 'Uri'. The argument is null or empty. Provide an argument that is not null or empty, and then try the command again. At C:\Users\XXXXXX\VScode\POST_method_try.ps1:29 char:43

• $usageReport = Invoke-RestMethod -Uri $usageGet1Uri -Method Get - ...
  

•                                       ~~~~~~~~~~~~~
  

  • CategoryInfo : InvalidData: (:) [Invoke-RestMethod], ParameterBindingValidationException
  • FullyQualifiedErrorId : ParameterArgumentValidationError,Microsoft.PowerShell.Commands.InvokeRestMethodCommand Invoke-WebRequest : Cannot validate argument on parameter 'Uri'. The argument is null or empty. Provide an argument that is not null or empty, and then try the command again. At C:\Users\XXXXXX\VScode\POST_method_try.ps1:34 char:28

• Invoke-WebRequest -Uri $blobLink -OutFile $fileName
  

•                        ~~~~~~~~~
  

  • CategoryInfo : InvalidData: (:) [Invoke-WebRequest], ParameterBindingValidationException
  • FullyQualifiedErrorId : ParameterArgumentValidationError,Microsoft.PowerShell.Commands.InvokeWebRequestCommand

Answer 1

Use Invoke-WebRequest instead for your first call,

$reportResponse = Invoke-WebRequest -Uri $generateReportUri -Method Post -Body ($reportRequest | ConvertTo-Json) -Headers @{ "Authorization" = "Bearer $((Get-AzAccessToken).Token)" }