#!/usr/bin/python

import os
import subprocess
import sys
import datetime
import shutil
from datetime import datetime, timedelta

import glob
import string
import re
import shlex

import smtplib
import email

#basic config - please do not change
HOSTNAME = os.uname()[1]
LOCKDIR = "/tmp/somedir" #LOCKDIR
LOGFILE = "/var/log/somelogfile" #LOGFILE
INNOBACKUPEX = "/usr/bin/innobackupex"
ALERTMAIL = "EMAILADDRESS@ADDRESS.COM" #to use multiple recepients, this needs to be turned into a list ["email1@bla.com", "email2@bla.com", "email3@bla.com", ...]


#backup configuration
#to use one binary over other, please put it at the start of the list, if it doesnt exist it will get skipped
COMPRESS = ["/usr/bin/pbzip2","/usr/local/sbin/pbzip2","/usr/bin/pigz","/usr/local/sbin/pigz"]
BACKUPDIR = '/home/backups/mysql/'
RETENTION  =int(7)
STREAMING = False
PARALEL = "4"
USEMEMORY = "1G"
CUSTOMOPT = "" #separate them with a space between, use syntax same as on the cli "--option=value --option2=value"
COMPRESSOPT = ""



########Bunch of checks that need to be ran before we proceed
########
#check which compression to use
compression = ""
for i in range(0, len(COMPRESS)):
    if os.path.isfile(COMPRESS[i]):
        compression = COMPRESS[i]
        break
#exit if compression is not set up
if compression == "":
    print ("none of compressions are available, please check which ones are available and which ones are provided")
    sys.exit()


#compression being used:
if ("pbzip2" in compression):
    backupSuffix = ".tar.bz2"
elif ("pigz" in compression):
    backupSuffix = ".tar.gz"
else:
    print ("wrong  compression")
    sys.exit()

#set backupname
createDate = datetime.today().strftime("%Y%m%d-%H%M%S")
if STREAMING:
    createName = "mysql_backups_" + HOSTNAME + "_" + createDate + "-streaming"
    createNameCompressed = "mysql_backups_" + HOSTNAME + "_" + createDate + "-streaming" + backupSuffix
else:
    createName = "mysql_backups_" + HOSTNAME + "_" + createDate
    createNameCompressed = "mysql_backups_" + HOSTNAME + "_" + createDate + backupSuffix

#get mysql datadir
commandToRun = "mysql -e 'select @@datadir;'"
args = shlex.split(commandToRun)
p = subprocess.Popen(args, stdout=subprocess.PIPE)
DATADIR = p.stdout.read().splitlines()[-1]
p.communicate()
#print (output.splitlines()[-1])
print (DATADIR)
if os.path.isdir(DATADIR) is False:
    print (DATADIR + "does not exit")
    sys.exit()


#check if it is slave
commandToRun = "mysql -e 'show slave status\G'"
args = shlex.split(commandToRun)
p = subprocess.Popen(args, stdout=subprocess.PIPE)
ISSLAVE = p.stdout.read()
p.communicate()
#if the machine is a slave add --slave-info to options
if ISSLAVE:
    CUSTOMOPT += " --no-timestamp --slave-info "
else:
    CUSTOMOPT += " --no-timestamp "


#the fun starts here - Tuborg
#skip disk check if .skipcheck is present in backupdir, remove after the run
def startBackups():
    if os.path.isfile(BACKUPDIR + ".skipcheck"):
        now = datetime.today().strftime("%Y-%m-%d %H:%M:%S")
        print(now + ": Skipping prerun disk space checks and running backups. skipcheck file will be removed")
        #function that runs backups
        os.remove(BACKUPDIR + ".skipcheck")
        runBackup()
    else:
        isRunnable()

#check total freeDisk disk space on partition containting BACKUPDIR, in bytes
def freeSpace(BACKUPDIR):
    st = os.statvfs(BACKUPDIR)
    freeDisk = int(st.f_bavail * st.f_frsize)
    return freeDisk

#get the size of the backup specified
def listBackups(BACKUPDIR, backupSuffix):
    backupNameRegex = os.path.join(BACKUPDIR + 'mysql_backups_' + HOSTNAME + '_' + '*' + backupSuffix)
    listBackups = glob.glob(backupNameRegex)
    return listBackups

#checks the site of the latest backup
def lastBackupSize():
    backupNames = listBackups(BACKUPDIR, backupSuffix)
    print (backupNames)
    if not backupNames:
        lastSize = 0
    else:
        lastSize = os.path.getsize(max(backupNames , key = os.path.getctime))
    return lastSize

#get size of the mysql datadir
def dirSize(path):
    total_size = 0
    for dirpath, dirnames, filenames in os.walk(path):
        for f in filenames:
            fp = os.path.join(dirpath, f)
            total_size += os.path.getsize(fp)
    return total_size

#prerun checks
def isRunnable():
    oldAge = 1
    lastSize = lastBackupSize()
    freeDisk = freeSpace(BACKUPDIR)
    #if streaming backup, we dont care about size of the datadir
    if STREAMING:
        datadirSize = 0
    else:
        datadirSize = dirSize(DATADIR)
    print("Size of last backup")
    print(lastSize)
    print("Free disk size")
    print(freeDisk)
    print("Datadir size")
    print(datadirSize)
    if ((freeDisk - lastSize - datadirSize) * 1.1) < (lastSize + datadirSize):
        sendMail("Cant run backups as there is not enough free disk space")
    print("All gucci")
    runBackup()

#removal of old backups
def removeOldBackups():
    #get list of all current backups
    listAllBackups = sorted(listBackups(BACKUPDIR, backupSuffix), reverse=True)
    print (listAllBackups)
    backupsToRemove = listAllBackups[RETENTION:]
    print (backupsToRemove)
    for i in backupsToRemove:
        print(i)
        os.remove(i)

#start with the backup process
def runBackup():
    print("runBackup")
    #start regular backups
    if not STREAMING:
        commandToRun = "nice -n 19 " + INNOBACKUPEX + " " + CUSTOMOPT + "--parallel=" + PARALEL + " " + BACKUPDIR + createName
        args = shlex.split(commandToRun)
        with open("/tmp/innobackupex.stdout.log", "a+") as f_stdout, open("/tmp/innobackupex.stderr.log", "a+") as f_stderr:
            p = subprocess.Popen(args, stdout=f_stdout, stderr=f_stderr)
        p.communicate()
        #check if backup was successful
        lastline = file("/tmp/innobackupex.stderr.log", "r").readlines()[-1]
        if not re.search("completed OK!", lastline):
            sendMail("Innobackupex failed, more information can be found in the log")
        print("innobackupex made it to the otherside")
        print("apply log now")

        #apply log to backup
        commandToRun = "nice -n 19 " + INNOBACKUPEX + " " + "--apply-log " + "--use-memory=" + USEMEMORY + " " + BACKUPDIR + createName
        print(commandToRun)
        args = shlex.split(commandToRun)
        print(args)
        with open("/tmp/apply.innobackupex.stdout.log", "a+") as f_stdout, open("/tmp/apply.innobackupex.stderr.log", "a+") as f_stderr:
            p = subprocess.Popen(args, stdout=f_stdout, stderr=f_stderr)
        p.communicate()

        #check if appylog was successful
        lastline = file("/tmp/apply.innobackupex.stderr.log", "r").readlines()[-1]
        if not re.search("completed OK!", lastline):
            sendMail("Innobackupex failed at applying log, more information can be found in the log")

        #compress mysql configs as well
        commandToRun = "tar -cz /etc/mysql/"
        print (commandToRun)
        args = shlex.split(commandToRun)
        print(args)
        with open(BACKUPDIR + createName + "/etc-mysql.tar.gz", "a+") as f_stdout, open("/tmp/tar_error.log", "a+") as f_stderr:
            p = subprocess.Popen(args, stdout=f_stdout, stderr=f_stderr)
        p.communicate()

        #compress the backed up directory
        with open(BACKUPDIR + createNameCompressed, "a+") as f_stdout, open("/tmp/tar_error.log", "a+") as tar_stderr:
            tarItUp = "tar -v -c " + BACKUPDIR + createName
            argsTar = shlex.split(tarItUp)
            p1 = subprocess.Popen(argsTar, stdout=subprocess.PIPE, stderr=tar_stderr)
            compressItUp = "nice -n 19 " + compression + COMPRESSOPT + " -c "
            argsCompress = shlex.split(compressItUp)
            p2 = subprocess.Popen(argsCompress, stdin=p1.stdout, stdout=f_stdout, stderr=tar_stderr)
            p1.stdout.close()  # Allow p1 to receive a SIGPIPE if p2 exits.
            p2.communicate()
            exitcodep2 = p2.returncode
            if exitcodep2 != 0:
                sendMail("Compression of backup has failed. Please check")
        try:
            shutil.rmtree(BACKUPDIR + createName)
        except:
            sendMail("Removal of the backupdir failed, please check. Tried to removed the following directory: " + BACKUPDIR + createName)
    #start streaming backup
    else:
        print("stuff")
        with open(BACKUPDIR + createNameCompressed, "a+") as f_stdout, open("/tmp/tar_error.log", "a+") as tar_stderr, open("/tmp/innobackupex.stderr.log", "a+") as inno_stderr:
            commandToRun = "nice -n 19 " + INNOBACKUPEX + " " + CUSTOMOPT + "--stream=tar" + " " + DATADIR
            argsCTR = shlex.split(commandToRun)
            print (argsCTR)
            print(commandToRun)
            p1 = subprocess.Popen(argsCTR, stdout=subprocess.PIPE, stderr=inno_stderr)
            compressItUp = compression + " " + COMPRESSOPT + " -c "
            argsCompress = shlex.split(compressItUp)
            p2 = subprocess.Popen(argsCompress, stdin=p1.stdout, stdout=f_stdout, stderr=tar_stderr)
            p1.stdout.close()  # Allow p1 to receive a SIGPIPE if p2 exits.
            p2.communicate()

            lastline = file("/tmp/innobackupex.stderr.log", "r").readlines()[-1]
            if not re.search("completed OK!", lastline):
                sendMail("Innobackupex failed on streaming backup, more information can be found in the log")

    removeOldBackups()
    try:
        shutil.rmtree(LOCKDIR)
    except:
        sendMail("unable to remove lockdir")


#sendmail and exit function
def sendMail(msgBody):
    sender = 'root@' + HOSTNAME
    receivers = ALERTMAIL
    msgBody = msgBody

    #print ("this works")
    #message = """From: """ + sender + """\nTo: """ + receivers + """\nSubject: backup failed on """ + HOSTNAME + """\n\n""" + msgBody + """\n"""

    #its still ugly, but ugly in mutliple lines
    message = ("From: " + sender + "\n"
    "To:" + receivers + "\n"
    "Subject: Backup failed on " + HOSTNAME + "\n\n"
    #"Subject: innobkp.sh on " + HOSTNAME + " has failed!!!" + "\n\n"
    + msgBody + "\n")

    #set smtp out server here:
    smtpObj = smtplib.SMTP('')
    smtpObj.sendmail(sender, receivers, message)
    print ("Successfully sent email")
    sys.exit()

try:
    if not os.path.exists(LOCKDIR):
        os.makedirs(LOCKDIR)
        startBackups()
    else:
        print (LOCKDIR + " already exists, script exiting")
        sendMail(LOCKDIR + " already exists, backup can not start. Please check logs")
except Exception as err:
    sendMail("Unexpected error please check, \n" + err)