MGraph suddenly stops working

Hi Harm,
I had some automation scripts running (for longer periods) where i had the same issue.
The script starts, after a while i get an error (authentication failure)

It seems that in Graph there's an expiry on an connection.
So after some time it will disconnect and you have to reconnect again.

I made a module built in my automations (connect graph with an app registration)
Then it checks each minute if the expiry will take place, if it will then it automaticly reconnects:


On top of the script:

function ConnectGraph {
    # Populate with the App Registration details and Tenant ID
    $appid = 'Your App-ID'
    $tenantid = 'Your-Tentant-ID'
    $secret = 'Your-Created-Secret'

    $body = @{
        Grant_Type    = "client_credentials"
        Scope         = "https://graph.microsoft.com/.default"
        Client_Id     = $appid
        Client_Secret = $secret
    }

    $connection = Invoke-RestMethod `
        -Uri https://login.microsoftonline.com/$tenantid/oauth2/v2.0/token `
        -Method POST `
        -Body $body

    $global:token = $connection.access_token
    $global:secureToken = ConvertTo-SecureString $global:token -AsPlainText -Force
    $global:expiresIn = $connection.expires_in
    $global:lastConnectTime = Get-Date

    Connect-MgGraph -AccessToken $global:secureToken
}

function EnsureGraphConnection {
    if ((Get-Date) -gt $global:lastConnectTime.AddSeconds($global:expiresIn - 60)) {
        Write-Host "Refreshing MSGraph connection..." -ForegroundColor Yellow
        connectgraph
    }
}

Then before running your code, kick of the function connectgraph, and set variable of $lastconnectiontime

connectgraph

Now your connected to MSGraph.
Build a loop (while) and put this part on top of that foreach loop:

   $success = $false
                while (-not $success) {
                    try {
                        EnsureGraphConnection
                       ###Your code here###
                        $success = $true
                    } catch {
                        if ($_.Exception.Message -match "token is expired") {
                            Write-Host "Token expired. Reconnecting to MSGraph..." -ForegroundColor Yellow
                            EnsureGraphConnection
                        } else {
                            Write-Host "Something went wrong, retrying in 5 seconds..." -ForegroundColor Red
                            Start-Sleep -Seconds 5
                        }
                    }
                }

after the else block you can also put "continue" to skip the current item