Creating an Email Bot in Apache NiFi

This is the first piece. After this, I will add some Spark Machine Learning to intelligently reply to emails from a list of pre-trained responses. With supervised learning, it will learn what emails to send to whom based on subject, who an email is from, body content, attachments, time of day, sender domain, and many other variables.

For now, it just reads some emails and checks for a hard-coded subject.

I could use this to trigger other processes, such as running a batch Spark job.

Since most people send and use HTML email, I will send and receive HTML emails to make it look more legit.

I could also run my fortune script and return that as my email content, making me sound wise, or pull in a random selection of tweets about Hadoop or even recent news, making the email very current and fresh.

Snippet example of a mixed content email message (attachments removed to save space)

Return - Path: < tspann@ hortonworks.com >
    Delivered - To: nifi@ dataflowdeveloper.com
Received: from walmailscan15.int.bizland.net by walmailscan15.int.bizland.net(
    Dovecot) with LMTP id + 5 RhOfCcB1jpZQAAf6S19A
for < nifi@ dataflowdeveloper.com > ;
Wed, 19 Oct 2016 12: 19: 13 - 0400
Return - path: < tspann@ hortonworks.com >
    Envelope - to: nifi@ dataflowdeveloper.com
Delivery - date: Wed, 19 Oct 2016 12: 19: 13 - 0400
Received: from[10.114.3.11](helo = smtp.maileig.com)
by walmailscan15.yourhostingaccount.com with esmtp(Exim)
id 1 bwtaC - 0006 dd - VQ
for nifi@ dataflowdeveloper.com;
Wed, 19 Oct 2016 12: 19: 12 - 0400
Received: from relayvx11c.securemail.intermedia.net([64.78.52.185]) by walimpinc11 with bizsmtp id xUKB1t0063zlEh401UKCnK;
Wed, 19 Oct 2016 12: 19: 12 - 0400 X - EN - OrigIP: 64.78.52.185 X - EN - IMPSID: xUKB1t0063zlEh401UKCnK Received: from emg - ca - 1 - 1. securemail.intermedia.net(localhost[127.0.0.1])(using TLSv1 with cipher AES256 - SHA(256 / 256 bits))(No client certificate requested) by emg - ca - 1 - 1. localdomain(Postfix) with ESMTPS id BEE9453F81
for < nifi@ dataflowdeveloper.com > ;
Wed, 19 Oct 2016 09: 19: 10 - 0700(PDT) Subject: test MIME - Version: 1.0 x - echoworx - msg - id: e50ca00a - edc5 - 4030 - a127 - f5474adf4802 x - echoworx - emg - received: Wed, 19 Oct 2016 09: 19: 10.713 - 0700 x - echoworx - message - code - hashed: 5841 d9083d16bded28a3c4d33bc505206b431f7f383f0eb3dbf1bd1917f763e8 x - echoworx - action: delivered Received: from 10.254.155.15([10.254.155.15]) by emg - ca - 1 - 1(JAMES SMTP Server 2.3.2) with SMTP ID 503
for < nifi@ dataflowdeveloper.com > ;
Wed, 19 Oct 2016 09: 19: 10 - 0700(PDT) Received: from MBX080 - W5 - CO - 2.e xch080.serverpod.net(unknown[10.224.117.104])(using TLSv1 with cipher AES256 - SHA(256 / 256 bits))(No client certificate requested) by emg - ca - 1 - 1. localdomain(Postfix) with ESMTPS id 6693053 F86
for < nifi@ dataflowdeveloper.com > ;
Wed, 19 Oct 2016 09: 19: 10 - 0700(PDT) Received: from MBX080 - W5 - CO - 2.e xch080.serverpod.net(10.224.117.104) by MBX080 - W5 - CO - 2.e xch080.serverpod.net(10.224.117.104) with Microsoft SMTP Server(TLS) id 15.0.1178.4;
Wed, 19 Oct 2016 09: 19: 09 - 0700 Received: from MBX080 - W5 - CO - 2.e xch080.serverpod.net([10.224.117.104]) by MBX080 - W5 - CO - 2.e xch080.serverpod.net([10.224.117.104]) with mapi id 15.00.1178.000;
Wed, 19 Oct 2016 09: 19: 09 - 0700 From: Timothy Spann < tspann@ hortonworks.com > To: "nifi@dataflowdeveloper.com" < nifi@ dataflowdeveloper.com > Thread - Topic: test Thread - Index: AQHSKiSFTVqN9ugyLEirSGxkMiBNFg == Date: Wed, 19 Oct 2016 16: 19: 09 + 0000 Message - ID: < D49AD137 - 3765 - 4 F9A - BF98 - C4E36D11FFD8@ hortonworks.com > Accept - Language: en - US Content - Language: en - US X - MS - Has - Attach: yes X - MS - TNEF - Correlator: x - ms - exchange - messagesentrepresentingtype: 1 x - ms - exchange - transport - fromentityheader: Hosted x - originating - ip: [71.168.178.39] x - source - routing - agent: Processed Content - Type: multipart / related;
boundary = "_004_D49AD13737654F9ABF98C4E36D11FFD8hortonworkscom_";
type = "multipart/alternative"--_004_D49AD13737654F9ABF98C4E36D11FFD8hortonworkscom_ Content - Type: multipart / alternative;
boundary = "_000_D49AD13737654F9ABF98C4E36D11FFD8hortonworkscom_"--_000_D49AD13737654F9ABF98C4E36D11FFD8hortonworkscom_ Content - Type: text / plain;
charset = "utf-8"
Content - Transfer - Encoding: base64

Python script to parse email messages:

#!/usr/bin/env python

""
"Unpack a MIME message into a directory of files."
""
import json
import os
import sys
import email
import errno
import mimetypes from optparse
import OptionParser from email.parser
import Parser

def main(): parser = OptionParser(
    usage = ""
    "\ Unpack a MIME message into a directory of files. Usage: %prog [options] msgfile "
    "")
parser.add_option(
    '-d', '--directory', type = 'string', action = 'store',
    help = ""
    "Unpack the MIME message into the named directory, which will be created if it doesn't already exist."
    "") opts, args = parser.parse_args() if not opts.directory: os.makedirs(opts.directory)
try: os.mkdir(opts.directory)
except OSError as e: #Ignore directory exists error
if e.errno != errno.EEXIST: raise msgstring = ''.join(str(x) for x in sys.stdin.readlines()) msg = email.message_from_string(msgstring) headers = Parser().parsestr(msgstring) response = {
    'To': headers['to'],
    'From': headers['from'],
    'Subject': headers['subject'],
    'Received': headers['Received']
}
print json.dumps(response) counter = 1
for part in msg.walk(): #multipart /* are just containers if part.get_content_maintype() == 'multipart': continue # Applications should really sanitize the given filename so that an # email message can't be used to overwrite important files filename = part.get_filename() if not filename: ext = mimetypes.guess_extension(part.get_content_type()) if not ext: # Use a generic bag-of-bits extension ext = '.bin' filename = 'part-%03d%s' % (counter, ext) counter += 1 fp = open(os.path.join(opts.directory, filename), 'wb') fp.write(part.get_payload(decode=True)) fp.close() if __name__ == '__main__': main() */

mailnifi.sh:

python mailnifi.py -d /opt/demo/email/"$@"

Python needs the email component for parsing the message. You can install this via PIP.

pip install email

I am using Python 2.7. You could use a newer Python 3.x. I recommend Python 3. See this documentation for more tips.

Here is the flow:

For the final part of the flow, I read the files created by the parsing, load them to HDFS, and delete them from the file system using the standard GetFile.