Port access service

General Discussion
1

I’ve composed a bash script that uses SSMPT to email me when a user access port 25565 (minecraft server). Here’s the .sh

#!/bin/bash

log_file="/var/log/minecraft-connections.log"
email_recipient="recipient@example.com"
smtp_host="smtp.example.com"
smtp_port="587"
email_username="your-email@example.com"
email_password="your-email-password"

# Continuously monitor port 25565 and log incoming connections
nc -klv localhost 25565 >> "$log_file" &

# Monitor the log file for changes and send email notifications
tail -fn0 "$log_file" | while read -r line
do
    echo "$line" | grep -q "localhost\[127.0.0.1\]:.*ESTABLISHED" && {
        echo "Incoming connection detected. Sending email notification..."
        echo -e "Subject: Minecraft Connection\n\n$line" | ssmtp -au "$email_username" -ap "$email_password" -h "$smtp_host" -p "$smtp_port" "$email_recipient"
        echo "Email notification sent."
    }
done

I’ve been having trouble getting it to run as a service - is there a .service template I can follow that works with Dietpi-Service?
Cheers as always.

2

You would need to create a systemd service and then add it to dietpi services list: dietpi-services > Add.

Simple tutorial for creating a service

systemd.service manpage

3

Hi Jappe,

Thanks for taking time to get back to me. I should add, I have made the bash script executable.
I wrote this, very basic minecraft-port-log01.service

[Unit]
Description= Minecraft 25565 port logging

[Service]
ExecStart=/home/dietpi/minecraft-port-logging-01.sh

[Install]
WantedBy=multi-user.target

Which always fails. Here’s the log:

│
│ ● minecraft-port-log01.service - Minecraft 25565 port logging                            │
│      Loaded: loaded (/etc/systemd/system/minecraft-port-log01.service; enabled; vendor   │
│ preset: enabled)                                                                         │
│      Active: failed (Result: exit-code) since Sat 2023-06-10 14:42:56 BST; 5s ago        │
│     Process: 3357 ExecStart=/home/dietpi/minecraft-port-logging-01.sh (code=exited,      │
│ status=203/EXEC)                                                                         │
│    Main PID: 3357 (code=exited, status=203/EXEC)                                         │
│         CPU: 756us                                                                       │
│                                                                                          │
│ Jun 10 14:42:56 MMServer03 systemd[1]: Started Minecraft 25565 port logging.             │
│ Jun 10 14:42:56 MMServer03 systemd[3357]: minecraft-port-log01.service: Failed to        │
│ execute /home/dietpi/minecraft-port-logging-01.sh: No such file or directory             │
│ Jun 10 14:42:56 MMServer03 systemd[3357]: minecraft-port-log01.service: Failed at step   │
│ EXEC spawning /home/dietpi/minecraft-port-logging-01.sh: No such file or directory       │
│ Jun 10 14:42:56 MMServer03 systemd[1]: minecraft-port-log01.service: Main process        │
│ exited, code=exited, status=203/EXEC                                                     │
│ Jun 10 14:42:56 MMServer03 systemd[1]: minecraft-port-log01.service: Failed with result  │
│ 'exit-code'.

The directory certainly exists, it’s the default dietpi directory.

4

you could try to add your bash code to our autostart script. Simply run dietpi-autostart > option 14 or 17.

1 Like
5

Ah, thanks @Joulinar - I haven’t used that functionality yet. I’ll give it a try.

EDIT:

That seems to be working. Result of journalctl -u dietpi-autostart_custom :

-- Journal begins at Sat 2023-06-10 16:10:16 BST, ends at Sat 2023-06-10 16:10:49 BST. --
Jun 10 16:10:17 MMServer03 systemd[1]: Started DietPi-AutoStart custom script.
Jun 10 16:10:17 MMServer03 custom.sh[642]: Listening on localhost 25565

Thanks very much for the pointer. So I assume the bash script is working - I wonder why the .service file couldn’t locate the bash script in the dietpi home folder.