Example: Internet Speed Tacker

Prerequisites

sudo apt install speedtest-cli

internet_speed_tracker.py

#!/usr/bin/env python3
import subprocess
import csv
import os
from datetime import datetime

#--------------CONFIGURATIONs--------------
BASE_DIR = os.path.dirname(os.path.abspath(__file__))
LOG_FILE = os.path.join(BASE_DIR, "speed_log.csv")

def run_speed_test():
    try:
        # Run speedtest in simple mode
        result = subprocess.check_output(["speedtest-cli", "--simple"]).decode("utf-8")
        
        # These settings parse the text. For example: Ping: 20 ms, Download: 50.5 Mbit/s, etc
        lines = result.split('\n')
        ping = lines[0].split()[1]
        download = lines[1].split()[1]
        upload = lines[2].split()[1]
        return ping, download, upload
    #These settings keep Speedtest from crashing by logging zeroes when the internet is totally down
    except Exception:
        return "0", "0", "0" 

def main():
    timestamp = datetime.now().strftime("%Y-%m-%d %H:%M:%S")
    ping, download, upload = run_speed_test()
    
    # Check if file exists to add headers if it doesn't
    file_exists = os.path.isfile(LOG_FILE)
    
    with open(LOG_FILE, mode='a', newline='') as f:
        writer = csv.writer(f)
        if not file_exists:
            writer.writerow(["Timestamp", "Ping (ms)", "Download (Mbit/s)", "Upload (Mbit/s)"])
        writer.writerow([timestamp, ping, download, upload])

if __name__ == "__main__":
    main()

Configure systemd

/etc/systemd/system/internet-speed-tracker.service

[Service]
ExecStart=/usr/bin/python3 "home/alang/internet_speed_tracker.py"
User=alang

/etc/systemd/system/internet-speed-tracker.timer

[Timer]
OnBootSec=5min
OnUnitActiveSec=2min
Persistent=true

[Install]
WantedBy=timers.target

Start the service

sudo systemctl daemon-reload
sudo systemctl enable --now internet-speed-tracker.timer