function Invoke-MaximizeDesignation {
<#
.SYNOPSIS
This wraps the APIGateway/Lambda for scaling environments.  Scales the environment up. Turns on all EC2 instances by designation.

.DESCRIPTION
Sends startup commands to EC2 instances where the alk:designation tag value = parameter Designation.

.PARAMETER Fqdn
Fully Qualified Domain Name of the API Gateway.  Each environment/account has a unique API Gateway endpoint.

.PARAMETER Designation
alk:designation tag to filter which instances to query. Case sensitive.

.PARAMETER ApiGatewayKey
Unique key for authenticating to the API Gateway.

.PARAMETER IsTest
Switch to determine if it should actually send the commands to the EC2 instances, or just report back what it will do, without actually sending instance commands.

.EXAMPLE
Invoke-MaximizeDesignation -fqdn "vyq7hqcx55.execute-api.us-east-1.amazonaws.com" -designation "ci1" -apiGatewayKey "123456789" -isTest $true

returns JSON:
[
    {
        "IsExcluded": false,
        "IsApp": false,
        "IsMic": false,
        "IsWeb": true,
        "IsRunning": true,
        "IsStopped": false,
        "InstanceId": "i-0fa21749b4e4b81ea",
        "Designation": "ci1",
        "HostName": "web27425",
        "Environment": "dev",
        "Service": "orb"
    }
]
.NOTES
Dev FQDN : vyq7hqcx55.execute-api.us-east-1.amazonaws.com
Staging FQDN : cox3133b67.execute-api.us-east-1.amazonaws.com
Qa FQDN :
#>
    [CmdletBinding()]

    Param (
        [Parameter(Mandatory = $true)]
        [string] $Fqdn,
        [Parameter(Mandatory = $true)]
        [string] $Designation,
        [Parameter(Mandatory = $true)]
        [string] $ApiGatewayKey,
        [Parameter(Mandatory = $true)]
        [switch] $IsTest
    )

    [System.Net.ServicePointManager]::SecurityProtocol = "Tls12"

    $jsonBody = '{"Designation":"' + $Designation + '","IsTest":"' + $IsTest + '"}'
    $response = Invoke-RestMethod -Uri "https://$Fqdn/Prod/MaximizeDesignation" -Headers @{"x-api-key"="$ApiGatewayKey"} -Method POST -body $jsonBody -ContentType "application/json"

    return $response
}