Deploy a template using a REST command from the az cli

Invoke-RESTDeployment.ps1

<#
    .Synopsis
        This script will deploy an Azure Resource Manager Template using the "az rest" command to invoke the REST api directly
    .Description
        This script will deploy an Azure Resource Manager Template using the "az rest" command to invoke the REST api directly.

        It deploys at resourceGroup scope but can be easily modified for any scope of deployment.

        The current account context must already be selected before executing the script, use 'az account show' to show the context
#>

Param(
    [string] [Parameter(Mandatory = $true)]$Location,
    [string] [Parameter(Mandatory = $true)]$ResourceGroupName,
    [string] [Parameter(Mandatory = $true)]$TemplateFile,
    [string] $TemplateParametersFile,
    [string] $DeploymentName = "rest-" + ((Get-Date).ToUniversalTime()).ToString('MMdd-HHmm'),
    [string] $mode = "incremental"
)

# get the management endpoint to invoke for the current context
$env = $(az cloud show -o json) | ConvertFrom-Json
$mgmtUri = $env.endpoints.resourceManager

# get the current subscriptionId for the resource uri
$ctx = $(az account show -o json) | ConvertFrom-Json
$subscriptionId = $ctx.id

$TemplateFile = [System.IO.Path]::GetFullPath([System.IO.Path]::Combine($PSScriptRoot, $TemplateFile))

$TemplateObj = Get-Content $TemplateFile -Raw | ConvertFrom-JSON
if (![string]::IsNullOrWhiteSpace($TemplateParametersFile)) {
    $TemplateParametersFile = [System.IO.Path]::GetFullPath([System.IO.Path]::Combine($PSScriptRoot, $TemplateParametersFile))
    $TemplateParametersObj = Get-Content $TemplateParametersFile -Raw | ConvertFrom-JSON
    if (($TemplateParametersObj | Get-Member -Type NoteProperty 'parameters') -ne $null) {
        $TemplateParametersObj = $TemplateParametersObj.parameters
    }
}
else {
    $TemplateParametersObj = @{ }
}

$body = @{
    properties = @{
        template   = $TemplateObj
        mode       = $mode
        parameters = $TemplateParametersObj
    }
}

$bodyJSON = $body | ConvertTo-Json -Compress -Depth 30
$bodyJSON = $bodyJSON.Replace('"', '""') # add quotes in order to pass the command via pwsh.exe

$method = "PUT"
$uri = "$($mgmtUri)subscriptions/$($subscriptionId)/resourceGroups/$($resourceGroupName)/providers/Microsoft.Resources/deployments/$($deploymentName)?api-version=2019-10-01"

$(az rest --method $method --uri "$uri" --body "$BodyJSON" --verbose)

# wait for the deployment to reach a terminal state
do {
    $status = $(az deployment group show -g "$resourceGroupName" -n "$deploymentName" -o json --verbose) | ConvertFrom-Json
    Start-Sleep 5
} while ($status.properties.provisioningState -eq "Running")

$status | ConvertTo-Json -Depth 10