SqlExpressBackupToS3.ps1

#SqlServerInstance
$sqlServerInstance = '<servername>\SQLEXPRESS'
$databases = @("Master","<databasename>")
#S3
$s3Bucket = '<s3bucketname>'
$region = 'us-east-1'
#Backup Settings
$backupPath = 'C:\temp\sqlbackups'
$timestamp = get-date -format yyyyMMddHHmmss
$zipFile = 'C:\temp\sqlbackups-'+$timestamp+'.zip'
$s3fileName = '<servername/databasename/whatever>/sqlbackups-'+$timestamp+'.zip'


foreach ($database in $databases) {
    Backup-SqlDatabase -Database $database -ServerInstance $sqlServerInstance -BackupFile (Join-Path $backupPath "$database-$timestamp.bak" )
}

if((Get-ChildItem $backupPath -force | Select-Object -First 1 | Measure-Object).Count -gt 0)
{
    Write-Host "backups found"
    Add-Type -assembly "system.io.compression.filesystem"
    [io.compression.zipfile]::CreateFromDirectory($backupPath, $zipFile)
    Write-S3Object -BucketName $s3Bucket -File $zipFile -Key $s3fileName -Region $region #-ServerSideEncryption AES256
    Remove-Item "$backupPath\*" -Confirm:$false -Force -Recurse
    Remove-Item $zipFile -Confirm:$false -Force
} else {
write-host "no backups found"
}