Backup-GitRepository.ps1

[CmdletBinding(SupportsShouldProcess)]
param
(
	[Parameter(Mandatory = $True, ValueFromPipeline=$True, ValueFromPipelineByPropertyName=$True)]
    [string]$Repository,

	[Parameter(Mandatory = $True)]
    [string]$Target,

	[Parameter(Mandatory = $False)]
    [int]$LastDays = 0
)

BEGIN {
    $ErrorActionPreference = "Stop"

    function Invoke-Git {
    <#
    .Synopsis
    Wrapper function that deals with Powershell's peculiar error output when Git uses the error stream.

    .Example
    Invoke-Git ThrowError
    $LASTEXITCODE

    #>
        [CmdletBinding()]
        param(
            [parameter(ValueFromRemainingArguments=$true)]
            [string[]]$Arguments
        )

        $argumentstext = $([string]::Join(' ', ($Arguments | %{ "'$_'" })))

        Write-Verbose "Executing Git: git.exe $argumentstext"

        & {
            [CmdletBinding()]
            param(
                [parameter(ValueFromRemainingArguments=$true)]
                [string[]]$InnerArgs
            )
            git.exe $InnerArgs
        } -ErrorAction SilentlyContinue -ErrorVariable fail @Arguments
        $resultcode = $LASTEXITCODE

        if ($fail) {
            $fail.Exception
        }

        if ($resultcode -ne 0) {
            Write-Error "Git.exe failed with exitcode $resultcode while executing: 'git.exe $argumentstext' on directory '$pwd'"
        }
    }
}

PROCESS {    
    $repo = Resolve-Path $Repository
    Write-Verbose "Processing $repo"

    pushd $repo

    if (Test-Path $Target -PathType Container) {
        $TargetFile = Join-Path $Target (Split-Path -Leaf $repo)
    } else {
        $TargetFile = $Target
    }

    if ([IO.Path]::GetExtension($TargetFile) -eq '') {
        if ($LastDays -gt 0) {
            $TargetFile += "-last-$LastDays-days.bundle"
        } else {
            $TargetFile += '.bundle'
        }
    }

    if (Test-Path $TargetFile) {
        $TargetFileBackup = "$TargetFile-previous"


        if (Test-Path $TargetFileBackup) {
            Remove-Item $TargetFileBackup -Force
        }
        Move-Item $TargetFile "$TargetFile-previous"
    }

    if ($PSCmdlet.ShouldProcess($repo, "Creating bundle '$TargetFile'")) {
        Invoke-Git fetch --all

        if ($LastDays -gt 0) {
            $since = "--since=$LastDays.days.ago"
        } else {
            $since = ""
        }

        $maxcount = 20
        $count = @(Invoke-Git log "$since" --all --pretty=oneline "-$maxcount").Count
        if ($count -eq 0) {
            Write-Warning "Skipping repository $repo because no commits are present"
        } else {
            if ($count -ge $maxcount) {
                Write-Verbose "Repository $repo contains at least $count commits"
            } else {
                Write-Verbose "Repository $repo contains $count commits"
            }
            Invoke-Git bundle create "$TargetFile" "$since" --all
        }
    }

    popd
}

END {
}

BackupGit.ps1

param
(
  [Parameter(Mandatory = $False)]
  [int]$LastDays = 0
)

[string[]]$repositories = @(
  'C:\SourceGIT\ContactCentre'
  'C:\SourceGIT\ContactCentre2'
  'C:\SourceGIT\ContactCentre3'
  'C:\SourceGIT\CTArchitect'
  'C:\SourceGIT\CTArchitect2'
  'C:\SourceGIT\CTArchitect3'
  'C:\SourceGIT\CTScript'
  'C:\SourceGIT\CTScript2'
  'C:\SourceGIT\Internal'
  'C:\SourceGIT\Projects'
  'C:\SourceGIT\Utility'
)

$target = "U:\SourceGIT-$env:COMPUTERNAME"

cp C:\SourceGIT\backup.ps1 $target

$repositories | . "C:\SourceGIT\Internal\UsefulScripts\Backup-GitRepository.ps1" -Target $target -LastDays $LastDays