check_recent_maildir

#!/usr/bin/env python3
#-------------------------------------------------------------------------------

import sys
import os
import argparse
import subprocess
import mailbox
import email.errors
import datetime
import dateutil.parser

#-------------------------------------------------------------------------------

_candebug = False
def candebug():
    global _candebug
    return _candebug
def setcandebug(value):
    global _candebug
    _candebug = value

def infomsg(msg):
    if candebug() == True:
        print(msg, flush=True)

def exitnagios(status,message):
    if status=="OK":
        exitcode = 0
    elif status=="WARNING":
        exitcode = 1
    elif status=="CRITICAL":
        exitcode = 2
    elif status=="UNKNOWN":
        exitcode = 3
    else:
        exitcode = 4
    print(status+": "+message, flush=True)
    sys.exit(exitcode)

#-------------------------------------------------------------------------------

extra_tz = None
def get_extra_tz():
    global extra_tz
    if extra_tz == None:
        extra_tz = {
            "A": 1 * 3600,
            "ACDT": 10.5 * 3600,
            "ACST": 9.5 * 3600,
            "ACT": -5 * 3600,
            "ACWST": 8.75 * 3600,
            "ADT": 4 * 3600,
            "AEDT": 11 * 3600,
            "AEST": 10 * 3600,
            "AET": 10 * 3600,
            "AFT": 4.5 * 3600,
            "AKDT": -8 * 3600,
            "AKST": -9 * 3600,
            "ALMT": 6 * 3600,
            "AMST": -3 * 3600,
            "AMT": -4 * 3600,
            "ANAST": 12 * 3600,
            "ANAT": 12 * 3600,
            "AQTT": 5 * 3600,
            "ART": -3 * 3600,
            "AST": 3 * 3600,
            "AT": -4 * 3600,
            "AWDT": 9 * 3600,
            "AWST": 8 * 3600,
            "AZOST": 0 * 3600,
            "AZOT": -1 * 3600,
            "AZST": 5 * 3600,
            "AZT": 4 * 3600,
            "AoE": -12 * 3600,
            "B": 2 * 3600,
            "BNT": 8 * 3600,
            "BOT": -4 * 3600,
            "BRST": -2 * 3600,
            "BRT": -3 * 3600,
            "BST": 6 * 3600,
            "BTT": 6 * 3600,
            "C": 3 * 3600,
            "CAST": 8 * 3600,
            "CAT": 2 * 3600,
            "CCT": 6.5 * 3600,
            "CDT": -5 * 3600,
            "CEST": 2 * 3600,
            "CET": 1 * 3600,
            "CHADT": 13.75 * 3600,
            "CHAST": 12.75 * 3600,
            "CHOST": 9 * 3600,
            "CHOT": 8 * 3600,
            "CHUT": 10 * 3600,
            "CIDST": -4 * 3600,
            "CIST": -5 * 3600,
            "CKT": -10 * 3600,
            "CLST": -3 * 3600,
            "CLT": -4 * 3600,
            "COT": -5 * 3600,
            "CST": -6 * 3600,
            "CT": -6 * 3600,
            "CVT": -1 * 3600,
            "CXT": 7 * 3600,
            "ChST": 10 * 3600,
            "D": 4 * 3600,
            "DAVT": 7 * 3600,
            "DDUT": 10 * 3600,
            "E": 5 * 3600,
            "EASST": -5 * 3600,
            "EAST": -6 * 3600,
            "EAT": 3 * 3600,
            "ECT": -5 * 3600,
            "EDT": -4 * 3600,
            "EEST": 3 * 3600,
            "EET": 2 * 3600,
            "EGST": 0 * 3600,
            "EGT": -1 * 3600,
            "EST": -5 * 3600,
            "ET": -5 * 3600,
            "F": 6 * 3600,
            "FET": 3 * 3600,
            "FJST": 13 * 3600,
            "FJT": 12 * 3600,
            "FKST": -3 * 3600,
            "FKT": -4 * 3600,
            "FNT": -2 * 3600,
            "G": 7 * 3600,
            "GALT": -6 * 3600,
            "GAMT": -9 * 3600,
            "GET": 4 * 3600,
            "GFT": -3 * 3600,
            "GILT": 12 * 3600,
            "GMT": 0 * 3600,
            "GST": 4 * 3600,
            "GYT": -4 * 3600,
            "H": 8 * 3600,
            "HDT": -9 * 3600,
            "HKT": 8 * 3600,
            "HOVST": 8 * 3600,
            "HOVT": 7 * 3600,
            "HST": -10 * 3600,
            "I": 9 * 3600,
            "ICT": 7 * 3600,
            "IDT": 3 * 3600,
            "IOT": 6 * 3600,
            "IRDT": 4.5 * 3600,
            "IRKST": 9 * 3600,
            "IRKT": 8 * 3600,
            "IRST": 3.5 * 3600,
            "IST": 5.5 * 3600,
            "JST": 9 * 3600,
            "K": 10 * 3600,
            "KGT": 6 * 3600,
            "KOST": 11 * 3600,
            "KRAST": 8 * 3600,
            "KRAT": 7 * 3600,
            "KST": 9 * 3600,
            "KUYT": 4 * 3600,
            "L": 11 * 3600,
            "LHDT": 11 * 3600,
            "LHST": 10.5 * 3600,
            "LINT": 14 * 3600,
            "M": 12 * 3600,
            "MAGST": 12 * 3600,
            "MAGT": 11 * 3600,
            "MART": 9.5 * 3600,
            "MAWT": 5 * 3600,
            "MDT": -6 * 3600,
            "MHT": 12 * 3600,
            "MMT": 6.5 * 3600,
            "MSD": 4 * 3600,
            "MSK": 3 * 3600,
            "MST": -7 * 3600,
            "MT": -7 * 3600,
            "MUT": 4 * 3600,
            "MVT": 5 * 3600,
            "MYT": 8 * 3600,
            "N": -1 * 3600,
            "NCT": 11 * 3600,
            "NDT": 2.5 * 3600,
            "NFT": 11 * 3600,
            "NOVST": 7 * 3600,
            "NOVT": 7 * 3600,
            "NPT": 5.5 * 3600,
            "NRT": 12 * 3600,
            "NST": 3.5 * 3600,
            "NUT": -11 * 3600,
            "NZDT": 13 * 3600,
            "NZST": 12 * 3600,
            "O": -2 * 3600,
            "OMSST": 7 * 3600,
            "OMST": 6 * 3600,
            "ORAT": 5 * 3600,
            "P": -3 * 3600,
            "PDT": -7 * 3600,
            "PET": -5 * 3600,
            "PETST": 12 * 3600,
            "PETT": 12 * 3600,
            "PGT": 10 * 3600,
            "PHOT": 13 * 3600,
            "PHT": 8 * 3600,
            "PKT": 5 * 3600,
            "PMDT": -2 * 3600,
            "PMST": -3 * 3600,
            "PONT": 11 * 3600,
            "PST": -8 * 3600,
            "PT": -8 * 3600,
            "PWT": 9 * 3600,
            "PYST": -3 * 3600,
            "PYT": -4 * 3600,
            "Q": -4 * 3600,
            "QYZT": 6 * 3600,
            "R": -5 * 3600,
            "RET": 4 * 3600,
            "ROTT": -3 * 3600,
            "S": -6 * 3600,
            "SAKT": 11 * 3600,
            "SAMT": 4 * 3600,
            "SAST": 2 * 3600,
            "SBT": 11 * 3600,
            "SCT": 4 * 3600,
            "SGT": 8 * 3600,
            "SRET": 11 * 3600,
            "SRT": -3 * 3600,
            "SST": -11 * 3600,
            "SYOT": 3 * 3600,
            "T": -7 * 3600,
            "TAHT": -10 * 3600,
            "TFT": 5 * 3600,
            "TJT": 5 * 3600,
            "TKT": 13 * 3600,
            "TLT": 9 * 3600,
            "TMT": 5 * 3600,
            "TOST": 14 * 3600,
            "TOT": 13 * 3600,
            "TRT": 3 * 3600,
            "TVT": 12 * 3600,
            "U": -8 * 3600,
            "ULAST": 9 * 3600,
            "ULAT": 8 * 3600,
            "UTC": 0 * 3600,
            "UYST": -2 * 3600,
            "UYT": -3 * 3600,
            "UZT": 5 * 3600,
            "V": -9 * 3600,
            "VET": -4 * 3600,
            "VLAST": 11 * 3600,
            "VLAT": 10 * 3600,
            "VOST": 6 * 3600,
            "VUT": 11 * 3600,
            "W": -10 * 3600,
            "WAKT": 12 * 3600,
            "WARST": -3 * 3600,
            "WAST": 2 * 3600,
            "WAT": 1 * 3600,
            "WEST": 1 * 3600,
            "WET": 0 * 3600,
            "WFT": 12 * 3600,
            "WGST": -2 * 3600,
            "WGT": -3 * 3600,
            "WIB": 7 * 3600,
            "WIT": 9 * 3600,
            "WITA": 8 * 3600,
            "WST": 14 * 3600,
            "WT": 0 * 3600,
            "X": -11 * 3600,
            "Y": -12 * 3600,
            "YAKST": 10 * 3600,
            "YAKT": 9 * 3600,
            "YAPT": 10 * 3600,
            "YEKST": 6 * 3600,
            "YEKT": 5 * 3600,
            "Z": 0 * 3600,
        }
    return extra_tz

def most_recent_date_simple(inbox):
    referencedate = None

    infomsg(inbox)
    try:
        inbox.clean()
        for key in inbox.iterkeys():
            infomsg(key)
            try:
                message = inbox[key]
            except email.errors.MessageParseError:
                # The message is malformed. Just leave it.
                continue
            date = message["Date"]
            try:
                candidatedate = dateutil.parser.parse(date, tzinfos=get_extra_tz())
            except:
                candidatedate = None
            infomsg(candidatedate)
            if (candidatedate!=None) and ((referencedate==None) or (candidatedate>referencedate)):
                referencedate = candidatedate
    except Exception as e:
        exitnagios("CRITICAL","there was an exception - "+str(e))

    return referencedate

def most_recent_date_recursive(inbox):
    referencedate = most_recent_date_simple(inbox)

    allfolders = inbox.list_folders()
    for folder in allfolders:
        nestedinbox = inbox.get_folder(folder)
        candidatedate = most_recent_date_recursive(nestedinbox)
        if (candidatedate!=None) and ((referencedate==None) or (candidatedate>referencedate)):
            referencedate = candidatedate

    infomsg(referencedate)
    return referencedate

def get_home_path(username):
    cmdline = ["/usr/bin/getent","passwd",username]
    completedproc = subprocess.run(cmdline,capture_output=True)
    output = completedproc.stdout.decode("utf-8").strip()
    errors = completedproc.stderr.decode("utf-8").strip()
    exitcode = completedproc.returncode

    if exitcode == 0:
        try:
            parts = output.splitlines()[0].split(":")
            return parts[5]
        except:
            return None
    else:
        return None

def dorecentmaildircall(username,warning,critical):
    try:
        if warning==None or warning=="":
            warning = 48
        else:
            warning = float(warning)
        if critical==None or critical=="":
            critical = 72
        else:
            critical = float(critical)
        userhomepath = get_home_path(username)
        if userhomepath==None or userhomepath=="" or os.path.isdir(userhomepath)==False:
            exitnagios("CRITICAL","the home folder '"+userhomepath+"' is not valid | maxage=-1")
        maildirpath = os.path.join(userhomepath,"Maildir")
        infomsg(maildirpath)
        inbox = mailbox.Maildir(maildirpath, factory=None)

        newest_date = most_recent_date_recursive(inbox)
        newest_date = newest_date.astimezone(datetime.timezone.utc)
        infomsg(newest_date)

        if (newest_date)==None:
            exitnagios("CRITICAL","no emails found | maxage=-1")
        else:
            now = datetime.datetime.now(datetime.timezone.utc)
            warninglimit = now - datetime.timedelta(hours=warning)
            criticallimit = now - datetime.timedelta(hours=critical)
            maxage = now - newest_date
            if newest_date < criticallimit:
                exitnagios("CRITICAL","no email in the last "+str(critical)+" hours - newest is "+str(newest_date)+" | maxage="+str(maxage.total_seconds()))
            elif newest_date < warninglimit:
                exitnagios("WARNING","no email in the last "+str(warning)+" hours - newest is "+str(newest_date)+" | maxage="+str(maxage.total_seconds()))
            else:
                exitnagios("OK","no issues found - newest is "+str(newest_date)+" | maxage="+str(maxage.total_seconds()))

        # Remove original message
        #inbox.lock()
        #inbox.discard(key)
        #inbox.flush()
        #inbox.unlock()
    except Exception as e:
        exitnagios("CRITICAL","there was an exception - "+str(e)+" | maxage=-1")

#-------------------------------------------------------------------------------

def parse_args():
    parser = argparse.ArgumentParser()
    parser.add_argument("-u", "--username",          action="store",       dest="username",         default="",                                   help="username to check")
    parser.add_argument("-w", "--warning",           action="store",       dest="warning",          default="",                                   help="warning hours")
    parser.add_argument("-c", "--critical",          action="store",       dest="critical",         default="",                                   help="critical hours")
    parser.add_argument("-®", "--debug",             action="store_true",  dest="debug",            default=False,                                help="be more verbose")
    args = parser.parse_args()
    return args

def main():
    args = parse_args()
    setcandebug(args.debug)
    dorecentmaildircall(args.username,args.warning,args.critical)

if __name__ == "__main__":
    main()

#-------------------------------------------------------------------------------