List all storage accounts for a resource group, get the maximum ingress and egress per minute for the past 30 days

Get-MaxStorageAccountThroughput.ps1

param (
    [String]$SubscriptionId,
    [String]$ResourceGroupName
    )

$nowTimestamp =  Get-Date -Format o
$30DaysAgoTimestamp = (Get-Date).AddDays(-30) | Get-Date -Format o

function Get-MaxMetric
{
    param (
        $ResourceId,
        $MetricType
    )

    Write-Host "Getting max ${MetricType} for ${ResourceId}"
    $request = "${ResourceId}/providers/microsoft.insights/metrics?interval=PT1M&timespan=${30DaysAgoTimestamp}/${nowTimestamp}&metricnames=${MetricType}&api-version=2019-07-01&aggregation=Total"
    $response = armclient GET $request | ConvertFrom-Json
    $max = $response.value[0].timeseries[0].data | Measure-Object -Property total -Maximum
    return $max.Maximum
}

armclient login

$storageAccounts = armclient GET "subscriptions/${SubscriptionId}/resourceGroups/${ResourceGroupId}/providers/Microsoft.Storage/storageAccounts?api-version=2021-01-01" | ConvertFrom-Json
$storageAccountIds = $storageAccounts.value.id

$storageMaxIngressAndEgress = @()
$storageAccountIds | ForEach-Object -Process {
    $maxIngress = Get-MaxMetric -ResourceId $_ -MetricType "Ingress"
    $maxEgress =  Get-MaxMetric -ResourceId $_ -MetricType "Egress"
    $storageMaxIngressAndEgress += [PSCustomObject]@{ 
        resourceId=$_ 
        maxIngressInGb=$maxIngress * 0.000000001
        maxEgressInGb=$maxEgress * 0.000000001
    }
}

$csvPath = ".\storageAccountUsage.csv"
$storageMaxIngressAndEgress | Export-Csv -Path $csvPath