Adds a Google Analytics script to all /teams/* site collections in an Office 365 Tenant.

Add-GoogleAnalyticsToO365.ps1

<#
.SYNOPSIS
Adds a Google Analytics script to all /teams/* site collections in an Office 
365 Tenant.  

.DESCRIPTION
When using Office 365 "/teams/*" managed path site collections as an extranet, some
clients would like to track their traffic using Google Analytics.  This is a 
simple script that adds the Google Analytics script to a UserCustomAction
using the http://github.com/officedev.pnp PowerShell cmdlet's to manage SharePoint
Online. 

NOTE: There is a better way to do this!  Using the Site extension method AddJsBlock 
would only require this to be done once per site collection.  There is an open 
Issue in PnP (https://github.com/OfficeDev/PnP/issues/454) which would enable PowerShell 
use of Site objects when calling AddJsBlock.  I will update the script when this 
functionality is incorported into the cmdlets.

This script requires the Office Dev PnP PowerShell Cmdlets.  To install, visit 
https://github.com/OfficeDev/PnP/tree/master/Binaries/PowerShell.Commands and select 
the proper MSI package for you environment.   

DISCLAIMER:  Script provided AS IS with no warranty.  Your mileage will vary.  Use 
             this script on a production tenant AT YOUR OWN RISK.          

.EXAMPLE
.\Add-GoogleAnalytics.ps1 -tenant https://twofficepnp1-admin.sharepoint.com -gaid UA-888889-00

#>
 

Param(
    [parameter(Mandatory=$true)][alias("tenant")]$TenantUrl="",
    [Parameter(Mandatory=$false)][alias("gaid")]$GoogleId=""
)
#Managed path to query for all site collections
$managedPath = "*teams*"

$ga_script = @"
(function(i,s,o,g,r,a,m){i['GoogleAnalyticsObject']=r;i[r]=i[r]||function(){
(i[r].q=i[r].q||[]).push(arguments)},i[r].l=1*new Date();a=s.createElement(o),
m=s.getElementsByTagName(o)[0];a.async=1;a.src=g;m.parentNode.insertBefore(a,m)
})(window,document,'script','//www.google-analytics.com/analytics.js','ga');
ga('create', '$GoogleId', 'auto');
ga('send', 'pageview');
"@;


function AddGoogleScript
{
	param 
	(
		$web
	)
	#Remove any previously deployed script
	Remove-SPOJavaScriptLink -Key "GoogleAnalytics" -Force -Web $web
	Write-Host "        Removed script from " $web.Url
	
	#Add the analytics script
	Add-SPOJavaScriptBlock -Key "GoogleAnalytics" -Script $ga_script -web $web	
	Write-Host "        Added script to " $web.Url
}

function WalkWeb 
{
	param 
	(
		$web,
		[System.Management.Automation.PSCredential] $creds
	)

	Write-Host "   Changing script for web " $web.Url
	AddGoogleScript( $web )

	#connect to the web to get a new client context 
	Connect-SPOnline -Url $web.Url -Credentials $creds
	$subwebs = Get-SPOSubWebs
	if ($null -ne $subwebs)
	{
		foreach($child in $subwebs)
		{
			Write-Host "   Walking web " $child.Url 
			WalkWeb $child $creds
		}
	}
	else
	{
		Write-Host "     No sub-webs for " $web.Url 
	}
}


########################################################
##                                                    ##
##               Main script                          ##
##                                                    ##
########################################################
#Get the tenant level site to query all site collections 
$creds = Get-Credential -Message "Enter Tenant Administrator Credentials"

#Connect to the Admin Tenant to query all site collections in managed path
Connect-SPOnline -Url $TenantUrl -Credentials $creds

#Get all site collections filtered to the teams managed path
$siteCollections = Get-SPOTenantSite | Where {$_.Url -like $managedPath} | Select Url 
foreach($site in $siteCollections)
{
	Write-Host "Connecting to site collection " $site.Url
	#connect to the site collection to get a new client context 
	Connect-SPOnline -Url $site.Url -Credentials $creds
		
	$rootWeb = Get-SPOWeb
	WalkWeb $rootWeb $creds
}