utils

Small tools needed to solve immediate tasks independently or as part of a project

• cronutil
• confutil.py
• sendmail.py
• simplewc.py

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cronutil

Description: Control wrapper for the schedule package
Dependencies: Python 3 (tested version 3.9.5)

Scheduler works only on a weekly scale. This is due to the use of the schedule package .
Target format: wD:HH:MM:SS, where:

wD - day of week unit: '1', '2', ... , '6', '7', '*'
HH - hour unit in 24-hours format: '00', '01', ... , '22', '23', '**'
MM - minute unit: '00', '01', ... , '58', '59', '**'
SS - second unit: '00', '01', ... , '58', '59', '**'

Units can be listed separated by commas.
Examples:
'*:**:**:**' - every second of every minute of every hour of every day
'*:**:**:*5' - every 05,15,25,35,45,55 seconds of every minute of every hour of every day
'*:2*:**:**' - every second of every minute of every 20,21,22,23 hours of every day
'*:2*:**:*5' - every 05,15,25,35,45,55 seconds of every minute of every 20,21,22,23 hours of every day
'3,5:2*:**:*5' - every 05,15,25,35,45,55 seconds every minute every 20,21,22,23 hours of Wednesday, Friday
'1,7:12:00:**' - every second 00 minutes 12 hours of Monday, Sunday
'1:07:00:00' - every 00 seconds 00 minutes 07 hours Monday

Example usage in Python:

from time import strftime
from cronutil import Scheduler


def now():
    print(strftime('%Y.%m.%d %H:%M:%S'))


cron = Scheduler()
cron.add('2,4:**:*0:00,15,30,45', now)
cron.start()
cron.add('2,4:**:59:59', cron.stop)

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confutil.py

Description: Parser of configs, arguments, parameters
Dependencies: Python 3 (tested version 3.9.5)

Example config to parse:

[main]
#   This block contains basic parameters


[httpd]
#   This block contains parameters for the http server

# Address to which to bind listening
#address=0.0.0.0;
# Port to which to bind listening. Port below 1024 requires root privileges.
port=8800;
# Working directory (available to everyone)
directory=www;

Example usage in Python:

from os import path
from confutil import Parse

conf = path.splitext(__file__)[0] + '.conf'
if path.exists(conf):
    print(Parse(parameters=conf, block='httpd'))

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sendmail.py

Description: Sending email from Python
Dependencies: Python 3 (tested version 3.9.5)

PARAMETERS	DESCRIPTION	DEFAULT
-u, --user	smtp valid user	REQUIRED
-p, --pass	smtp valid password	REQUIRED
-d, --dest	destination addresses	REQUIRED
[-h]	print help and exit
[--smtp]	smtp hostname or ip address	smtp.gmail.com
[--port]	smtp port number	587
[--stls]	smtp required TLS	True
[--from]	mail from alias	--user value
[--subj]	mail subject	'no subject'
[--text]	mail body text	'no text'
[--type]	mail body type: plain, html	plain
[--file]	mail attachment files	None
[--time]	minutes of attempts to send	3

Example usage in terminal with Python:

python3 ./sendmail.py -u user@gmail.com -p pass -d addr1@gmail.com,addr2@gmail.com

Example usage in terminal with make the script executable:

chmod u+x ./sendmail.py
./sendmail.py -u user@gmail.com -p pass -d addr1@gmail.com,addr2@gmail.com

Example usage in Python:

from sendmail import Mail

msg = Mail(smtp_user='user@gmail.com', smtp_pass='pass', mail_dest='addr1@gmail.com,addr2@gmail.com')
log = msg.send()
print(log)

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simplewc.py

Description: Update Let's Encrypt wildcard certificate with DNS-01 challenge
Dependencies: Python 3 (tested version 3.9.5), installed or downloaded acme.sh, installed dnspython package, dns is supported to dynamic update

PARAMETERS	DESCRIPTION	DEFAULT
--domain	domain for which the wildcard certificate is issued	REQUIRED
--server	master server containing the domain zone	REQUIRED
--keyname	name of the key to update the zone	REQUIRED
--keydata	content of the key to update the zone	REQUIRED
[-h]	print help and exit
[--acmepath]	alternative path to bin (example: ~/.acme.sh/acme.sh)	None
[--force]	"force" argument for the acme.sh	False
[--test]	"test" argument for the acme.sh	False

Example usage in cron with Python:

# at 00:00 on Monday
0 0 * * 1 /usr/bin/python3 ~/simplewc.py --domain EXAMPLE.COM --server 8.8.8.8 --keyname KEY --keydata YOU_KEY_CONTENT > /dev/null
# 00:00 on day-of-month 1 and 15
0 0 1,15 * * /usr/bin/python3 ~/simplewc.py --domain EXAMPLE.COM --server dyn.dns.he.net --keyname - --keydata YOU_DDNSKEY > /dev/null

Example usage in terminal with make the script executable:

chmod u+x ./simplewc.py
./simplewc.py --domain EXAMPLE.COM --server 8.8.8.8 --keyname KEY --keydata YOU_KEY_CONTENT --test --force
./simplewc.py --domain EXAMPLE.COM --server dyn.dns.he.net --keyname - --keydata YOU_DDNSKEY --test --force

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