Use Restic to perform backups to Backblaze B2.

Backup-Folders.ps1

#requires -version 4
<#
.SYNOPSIS
  Restic backup script.

.DESCRIPTION
  Use Restic to perform backups to Backblaze B2.

.PARAMETER Repository
  The path to the Restic repository, e.g. 'b2:my-named-repo'.

.PARAMETER Folder
  The folder to be backed up, e.g. 'E:\richard\Documents'

.PARAMETER ExcludesFile
  A file of excludes, e.g. 'E:\richard\Source\scripts\excludes.txt'.

.INPUTS
  None.

.OUTPUTS
  None.

.NOTES
  Version:        1.0
  Author:         Richard Bogle
  Creation Date:  2019-11-14
  Purpose/Change: Initial script development

  Restic was installed via Scoop.
  Set up [Task Scheduler](https://community.spiceworks.com/how_to/17736-run-powershell-scripts-from-task-scheduler).

.EXAMPLE
  PS C:\> . .\Backup-Folders.ps1 -Folder 'E:\richard\Documents' -Repository 'b2:bogle-restic' -ExcludesFile 'E:\richard\Source\scripts\excludes.txt'
  
#>

Param (
  [Parameter(Mandatory=$True)]
  [string]$Repository,

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

  [Parameter()]
  [string]$ExcludesFile
)

# Set Error Action to Silently Continue
#$ErrorActionPreference = 'SilentlyContinue'

Function SetupEnvironment {
  Param ()

  Begin {
    Import-Module CredentialManager
  }

  Process {
    $env:RESTIC_REPOSITORY=$Repository
    $credential = Get-StoredCredential -Target bogle-restic -AsCredentialObject
    $env:B2_ACCOUNT_ID = $credential.UserName
    $env:B2_ACCOUNT_KEY = $credential.Password
    $credential = Get-StoredCredential -Target restic -AsCredentialObject
    $env:RESTIC_PASSWORD = $credential.Password
  }

  End {
  }
}

Function BackupFolders {
  Param ()

  Begin {
    SetupEnvironment
    $logFile = $PSCommandPath.replace('.ps1', '.log')
    Start-Transcript -Path $logFile
    Write-Host 'Backup folders to B2 using Restic.'
  }

  Process {
    Try {
      if (-not (restic snapshots)) {
        throw 'Cannot find repository.'
      }
      if (-not [string]::IsNullOrWhiteSpace($ExcludesFile) -and (Test-Path -Path $ExcludesFile)) {
        restic backup $Folder --exclude-file=$ExcludesFile
      }
      else {
        restic backup $Folder
      }
    }

    Catch {
      Write-Error $_.Exception.Message
      Break
    }
  }

  End {
    If ($?) {
      Write-Host 'Completed Successfully.'
      Write-Host ' '
    }
    Stop-Transcript
  }
}

BackupFolders