# This script checks that a cluster's File Share Witness is online.

# check_file_share_witness v0.01
# Copyright (C) 2016 Minh Van Le
# License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
# This is free software: you are free to change and redistribute it.
# There is NO WARRANTY, to the extent permitted by law.
# 
# Written by Minh Van Le <mvanle@sourceforge.net>

[CmdletBinding()]
param (
    [string] $cluster,
    [string] $node,
    [string] $fsw,
    [switch] $c
)

#/********************************************************************************
# * Functions
# ********************************************************************************/

function usage() {
    "Usage: check_file_share_witness [-cluster:cluster_name] [-node:node_name] [-fsw:share_path] [-c]"
}

function isNodeUp() {
    $cmd = "-split (cluster $clusterOption node $node | select-string 'Up')"
    $output = invoke-expression $cmd
    $output[-1] -eq "up"
}

function isFileShareWitnessOnline() {
    $cmd = "-split (cluster $clusterOption res 'File Share Witness' | select-string 'Online')"
    $output = invoke-expression $cmd
    $output[-1] -eq "online"
}

function getFileShareWitness() {
    $cmd = "-split (cluster $clusterOption res 'File Share Witness' /priv | select-string 'SharePath')"
    $output = invoke-expression $cmd
    $output[-1]
}

function doCheck() {
    if ($node) {
        if (! (isNodeUp)) {
            write-host "$node is not up"
            return $false
        }
    }

    if ($fsw) {
        if (! ($fsw -eq (getFileShareWitness))) {
            write-host "Path is not a witness $fsw"
            return $false
        }
    }

    if (! (isFileShareWitnessOnline)) {
        write-host "File Share Witness is not online"
        return $false
    }

    #/* All passed */
    return $true
}

function returnNagiosResult() {
    if ($error) {
        exit 3      #// Unknown
    } elseif ($result -eq $false) {
        if ($c) {
            exit 2  #// Critical
        } else {
            exit 1  #// Warning
        }
    } elseif ($result -eq $true) {
        "OK: " + (getFileShareWitness)
        exit 0
    } else {
        "Huh ?"
        exit 3      #// Unknown
    }
}

#/********************************************************************************
# * Main
# ********************************************************************************/

if (! $psboundparameters.count) {
    usage
    exit 3
}

$error.clear()

if ($cluster) {
    $clusterOption = " /cluster:$cluster "
}

$result = doCheck

returnNagiosResult