# Script Name: powerssh
# Version: 1.1.0 (9. July, 2014)
# Author: Sveinn Steinarsson
# Description: Use Powershell to connect to a remote server via SSH and run a shell script/command

# Prerequisite:
#   plink.exe in script path (http://www.chiark.greenend.org.uk/~sgtatham/putty/download.html)

# Examples:
# With key file (*.ppk) and script file
# .\powerssh.ps1 -server hostname -login username -key keyfile.ppk -script task.sh
# With key file and command
# .\powerssh.ps1 -server hostname -login username -key keyfile.ppk -cmd "ls; pwd"

Param (
	[string]$server = $(Throw "Please provide a server hostname/ip"),
	[string]$login = $(Throw "Please provide a login username"),
	[string]$key,
	[string]$pw,
	[string]$script,
	[string]$cmd,
	[switch]$batch = $false,
	[switch]$agentForwarding = $true,
	[switch]$verbose = $false,
	[switch]$acceptHostKey = $true # For convenient. Make sure the server is the computer you think it is.
)

$scriptPath = Split-Path -Parent $MyInvocation.MyCommand.Path
$plinkPath = Join-Path -Path $scriptPath -Childpath "Plink.exe"

if (-not (Test-Path $plinkPath)){
	Throw "Missing Plink.exe in script path. Please download it from http://the.earth.li/~sgtatham/putty/latest/x86/plink.exe"
}

if ($key -eq "" -and $pw -eq "") {
	Throw "You must supply either a password or key file."
}

if ($script -eq "" -and $cmd -eq "") {
	Throw "You must supply either a shell script file or command."
}

if ($key -ne "" -and $pw -ne "") {
	Write-Output "Notice: Only password or key file is required. Using key file."
}

if ($script -ne "" -and $cmd -ne "") {
	Write-Output "Notice: Only script file or command is required. Using script file."
}

if ($acceptHostKey -eq $true) {
	$command = "echo Y|" + $plinkPath
} else {
	$command = $plinkPath
}

$command += " -ssh " + $server + " -l " + $login

if ($key -ne "") {
	$command += " -i " + $key
} else {
	$command += " -pw " + $pw
}

if ($batch -eq $true) {
	$command += " -batch" 
}

if ($agentForwarding -eq $true) {
	$command += " -a"
}

if ($verbose -eq $true) {
	$command += " -v"
}

if ($script -ne "") {
	$command += " -m " + $script
} else {
	$command += ' "' + $cmd + '"'
}

$command += " 2>&1"

if ($verbose -eq $true) {
	Write-Output "Command to Plink:"
	Write-Output $command  # Write out the command for debugging
	Write-Output ""
}

$output = Invoke-Expression $command

if ($LastExitCode -ne 0) {
	Throw $output
} else {
	Write-Output $output
	Exit 0
}