Powershell Script to download backup from a Ubiquiti UniFi Controller or Cloud Key

Get-UniFiBackup.PS1

<#

.NOTES

    Author:        Shannon Brooks
    Date:          Dec 1st, 2016
    Licence:       Creative Commons Attribution-ShareAlike 4.0 International License
    License URL:   http://creativecommons.org/licenses/by-sa/4.0/

.SYNOPSIS

    Downloads a backup file from a UniFi controller

.DESCRIPTION

    Downloads a backup file from a UniFi controller using the (undocumented) UniFi controller API

.EXAMPLE

    C:\PS> .\Get-UniFiBackup.ps1 -Server 'localhost' -Port 8443 -Username 'admin' -Password 'XXXXXXXX' -BackupDays -1

    Will download a full backup from the server 'localhost'

.PARAMETER Server

    Server name or IP address

.PARAMETER Port

    Server HTTPS port

.PARAMETER Username

    Admin user to login with

.PARAMETER Password

    Password for the admin user

.PARAMETER BackupLocation

	Location to save the backups, will be created if it doesn't exist

.PARAMETER BackupDays

    Number of days of data to retain in the backup
    
    Values in UniFi interface are 7, 30, 60, 90, 180, 365, and -1 (unlimited)

.PARAMETER BackupTimeStampFormat

    Format for backup time stamp

    See Get-Date for formatting options

.PARAMETER AcceptOnlyValidCertificates

    Reject invalid or self signed SSL certificates

#>
[CmdletBinding()]
Param(
    
    [Parameter(Mandatory=$False)]
    [string]
    $Server="localhost",
    
    [Parameter(Mandatory=$False)]
    [int]
    $Port=8443,
    
    [Parameter(Mandatory=$False)]
    [string]
    $Username="admin",
    
    [Parameter(Mandatory=$True)]
    $Password,
    
    [Parameter(Mandatory=$False)]
    [string]
    $BackupLocation='.\',
    
    [Parameter(Mandatory=$False)]
    [int]
    $BackupDays=7,

    [Parameter(Mandatory=$False)]
    [string]
    $BackupTimeStampFormat="yyyy-MM-dd-Hmmss",

    [switch]
    $AcceptOnlyValidCertificates
    
)

# make sure backup location exists
$BackupLocation =  $ExecutionContext.SessionState.Path.GetUnresolvedProviderPathFromPSPath($BackupLocation)
If ( -not ( Test-Path -Path $BackupLocation -PathType Container -ErrorAction SilentlyContinue ) )
{
    New-Item -Path $BackupLocation -ItemType Directory -ErrorAction Stop
}

# accept all SSL certs
If ( -not ( $AcceptOnlyValidCertificates.IsPresent ) )
{
    [System.Net.ServicePointManager]::ServerCertificateValidationCallback = { $True }
}

# construct server base URI
$BaseURI = 'https://' + $Server + ':' + $Port

# login
$Response = Invoke-RestMethod `
    -Method Post `
    -Uri "$BaseURI/api/login" `
    -Body $( @{ username=$Username; password=$Password } | ConvertTo-Json ) `
    -SessionVariable 'UniFiSession'
If ( $Response.meta.rc -ne 'ok' ) { Write-Error "LOGIN ERROR" -ErrorAction Stop }

# generate the backup file
$Response = Invoke-RestMethod `
    -Method Post `
    -WebSession $UniFiSession `
    -Uri "$BaseURI/api/s/default/cmd/system" `
    -Body $( @{ cmd='backup'; days=$BackupDays } | ConvertTo-Json )

# download the backup file
Invoke-WebRequest `
	-Uri "$BaseURI$($Response.data.url)" `
	-WebSession $UniFiSession `
	-OutFile "$BackupLocation\$Server`_$(Get-Date -f $BackupTimeStampFormat).unf"

# logout
$Response = Invoke-WebRequest `
	-Uri "$BaseURI/logout" `
	-WebSession $UniFiSession

#EOF