#!/usr/bin/env python
# -*- coding: utf-8 -*-

import os
import sys
import socket
import smtplib
from email.MIMEText import MIMEText
from email.Header import Header
from email.Utils import formatdate

# =====================================
# CONFIG

TEST = False

# Email settings
FROM       = 'ENTER FROM-ADDRESS' # e.g. root@freenas.local
TO         = 'ENTER TO-ADDRESS' # e.g. youename@gmail.com

# Gmail SMTP settings
LOGIN      = 'ENTER GMAIL LOGIN ID' # e.g. yourname@gmail.com
PASSWORD   = 'ENTER GMAIL LOGING PASSWORD '

# Change the following list of the disks
DISKS      = [
    '/dev/ada0',
    '/dev/ada1',
    '/dev/ada2',
    '/dev/ada3',
]

# Usually you don't need to change the following settings
ZPOOLCMD   = '/sbin/zpool'
SMARTCMD   = '/usr/local/sbin/smartctl'

ZPOOL_FINEMSG = "all pools are healthy"
SMART_FINEMSG = "SMART overall-health self-assessment test result: PASSED"

class Gmailer(object):

    _message = None

    def __init__(self, from_addr, to_addr, subject, body, encoding):
        msg = MIMEText(body, 'plain', encoding)
        msg['Subject'] = Header(subject, encoding)
        msg['From'] = from_addr
        msg['To'] = to_addr
        msg['Date'] = formatdate()
        self._message = msg
    
    def send_email(self, login, password):
        try:
            s = smtplib.SMTP('smtp.gmail.com', 587)
            s.ehlo()
            s.starttls()
            s.ehlo()
            s.login(login, password)
            s.sendmail(self._message['From'], [self._message['To']], self._message.as_string())
            s.close()
        except Exception, e:
            print e
            sys.exit(1)

# execute a command and return its output
def run_command(c):
    try:
        proc = os.popen(c)
        out  = proc.read().strip()
        return out
    except Exception, e:
        print e
        sys.exit(1)

# create a summary-text of failed-command's output and additional details
def create_summary(failed, details):
    s  = failed
    s += "\n----------\n\n"
    s += details
    return s

def main():

    hostname = socket.gethostname()

    # Zpool Status checking
    zpool_status_x =  run_command(ZPOOLCMD + " status -x")

    if TEST or zpool_status_x.find(ZPOOL_FINEMSG) == -1:
        zpool_status = run_command(ZPOOLCMD + " status")
        text = create_summary(zpool_status_x, zpool_status)
        subject = ' '.join(['[FreeNAS]', hostname, 'ZPool Status'])
        mailer = Gmailer(FROM, TO, subject, text, 'utf-8')
        mailer.send_email(LOGIN, PASSWORD)

    # SMART checking
    for disk in DISKS:
        smart_health = run_command(SMARTCMD + ' --health ' + disk)
        if TEST or smart_health.find(SMART_FINEMSG) == -1:
            smart = run_command((SMARTCMD + ' --all ' + disk))
            text = create_summary(smart_health, smart)
            subject = ' '.join(['[FreeNAS]', hostname, 'S.M.A.R.T.', disk])
            mailer = Gmailer(FROM, TO, subject, text, 'utf-8')
            mailer.send_email(LOGIN, PASSWORD)

if __name__ == '__main__':
    main()