Docker (Windows) Cleanup

docker_cleanup.ps1

# View space taken up
docker system df -v

# Safe cleanup commands (won't drop anything that is "dangling" because a container is just stopped)
docker image prune
docker builder prune

# PS Function to shrink WSL drive (run as administrator)
function docker_compact {
    param(
        [string]$VhdxPath = "$env:LOCALAPPDATA\Docker\wsl\disk\docker_data.vhdx"
    )

    # Ensure running as administrator
    $isAdmin = (
        [Security.Principal.WindowsPrincipal] `
            [Security.Principal.WindowsIdentity]::GetCurrent()
    ).IsInRole(
        [Security.Principal.WindowsBuiltInRole]::Administrator
    )

    if (-not $isAdmin) {
        Write-Host ""
        Write-Host "This function must be run from an elevated PowerShell session." -ForegroundColor Red
        Write-Host "Please reopen PowerShell as Administrator and try again."
        Write-Host ""
        return
    }

    Write-Host ""
    Write-Host "!!!!!!!!!!!!!!!!!!!!!!!!!!!" -ForegroundColor Yellow
    Write-Host ""
    Write-Host "ENSURE DOCKER IS NOT RUNNING" -ForegroundColor Yellow
    Write-Host ""
    Write-Host "!!!!!!!!!!!!!!!!!!!!!!!!!!!" -ForegroundColor Yellow
    Write-Host ""

    Read-Host "Press Enter to continue"

    if (-not (Test-Path $VhdxPath)) {
        Write-Error "VHDX file not found: $VhdxPath"
        return
    }

    $beforeSizeBytes = (Get-Item $VhdxPath).Length
    $beforeSizeGB = [math]::Round($beforeSizeBytes / 1GB, 2)

    Write-Host ""
    Write-Host "Current VHDX size: $beforeSizeGB GB"

    Write-Host ""
    Write-Host "Shutting down WSL..."
    wsl --shutdown

    $diskpartScript = @"
select vdisk file="$VhdxPath"
attach vdisk readonly
compact vdisk
detach vdisk
exit
"@

    $tempFile = New-TemporaryFile

    try {
        Set-Content -Path $tempFile -Value $diskpartScript

        Write-Host ""
        Write-Host "Running diskpart..."
        diskpart /s $tempFile

        if ($LASTEXITCODE -ne 0) {
            Write-Error "diskpart failed with exit code $LASTEXITCODE"
            return
        }

        $afterSizeBytes = (Get-Item $VhdxPath).Length
        $afterSizeGB = [math]::Round($afterSizeBytes / 1GB, 2)

        $savedBytes = $beforeSizeBytes - $afterSizeBytes
        $savedGB = [math]::Round($savedBytes / 1GB, 2)

        Write-Host ""
        Write-Host "Compaction complete." -ForegroundColor Green
        Write-Host "Before: $beforeSizeGB GB"
        Write-Host "After : $afterSizeGB GB"
        Write-Host "Saved : $savedGB GB"
        Write-Host ""
    }
    finally {
        if (Test-Path $tempFile) {
            Remove-Item $tempFile -Force
        }
    }
}