Simulating Linux SSH in PowerShell for ONTAP

There’s no native way in Windows of doing> ssh [user@]hostname command

So - as a curiosity - I thought I’d write the function. This works for NetApp Clustered Data ONTAP/ONTAP.

The Script

Save as say ssh.ps1 and import into your PowerShell session using . .\ssh.ps1 (dot space dot), then run in PowerShell as>

ssh [user@]hostname command

# The following function simulates the Linux SSH syntax in PowerShell for ...

# ... NetApp Clustered Data ONTAP, in conjunction with the Data ONTAP PSTK:

# > ssh [user@]hostname command

# It takes advantage of the NcCredential feature of the Data ONTAP PSTK ...

# ... use> Add-NcCredential CONTROLLER = Add credentials

Function SSH{

  ## GENERIC: LOAD THE DATA ONTAP PSTK ##

  If(!(Get-Module DataONTAP)){

    [Void](Import-Module DataONTAP -ErrorAction SilentlyContinue)

    If(!(Get-Module DataONTAP)){ "Failed to load DataONTAP PSTK!"; RETURN }

  }

 

  ## SCENARIO 1: No Argument/No 2nd Arg (No $Args[0]/No $Args[1]) ##

  If(!$Args[0]){ "SYNTAX ERROR: 0 arguments detected (2 expected)!"; RETURN }

  If(!$Args[1]){ "SYNTAX ERROR: 1 argument detected (2 expected)!"; RETURN }

 

  ## PROCESS INPUT $Arg[0] and $Arg[1] ##

  [System.Array]$Arg0 = $Args[0].Split("@")

  If($Arg0.Count -eq 2){

    [String]$User = $Arg0[0]

    [String]$Host = $Arg0[1]

  }elseif($Arg0.Count -eq 1){

    [String]$User = ""

    [String]$Host = $Arg0[0]

  }else{

    "SYNTAX ERROR: Too many @ in $Args[0]!"; RETURN

  }

 

  ## CHECK HOST CREDENTIAL ##

  $GetNcCred = Get-NcCredential $Host

  If(!$GetNcCred){

    "ERROR: No credentials for $Host in the NcCredentials cache. To add use> Add-NcCredential $Host"; RETURN

  }

  $NcCredUser = $GetNcCred.Credential.Username

  If($User -and ($NcCredUser -ne $User)){

    "ERROR: NcCredential for $Host uses user $NcCredUser and not $User. To add correct credential use> Add-NcCredential $Host"; RETURN

  }

 

  ## EXAMINE CurrentNcController ##     

  If($Global:CurrentNcController){

    If($Global:CurrentNcController.Name -ne $Host){ $Global:CurrentNcController = $Null}

    else{

      $TempUser = $Global:CurrentNcController.Credentials.Username

      $TempDomain = $Global:CurrentNcController.Credentials.Domain

      If($TempDomain){ $TempUser += ("\" + $TempDomain) }

      If($User -ne $TempUser){ $Global:CurrentNcController = $Null }

    }

  }

 

  ## CONNECT ##

  If(!$Global:CurrentNcController){

    [Void](Connect-NcController $Host -ErrorAction SilentlyContinue)

    If(!$Global:CurrentNcController){"ERROR: Failed to connnect to $Host!"; RETURN}

  }

 

  ## RUN COMMAND ##

  (Invoke-NcSsh $Args[1]).Value

}

Example

Image: Running SSH [user@]hostname command in PowerShell

Note: Not sure if it’s because I’m using a simulator, but this doesn’t run fast, the Invoke-NcSSH isn’t quick.