Server does not appear to be listening

[CloudDog23]

Brand new Raspberry Pi 4 8GB
I have installed CLI only Raspian
I have run sudo raspi-config and set the Memory Split 16
I have run sudo apt-get update and sudo apt-get upgrade
I have run sudo apt install default-jdk
I have created and CD'd to the ~/nukkit
I have downloaded nukkit-1.0-SNAPSHOT.jar from https://ci.nukkitx.com/job/NukkitX/job/Nukkit/job/master/
I have run the command with the following output

pi@raspberrypi-mc:~/nukkit $ java -Xms1G -Xmx1G -jar nukkit-1.0-SNAPSHOT.jar
WARNING: sun.reflect.Reflection.getCallerClass is not supported. This will impact performance.
01:48:34 [INFO ] Welcome! Please choose a language first!
01:48:34 [INFO ] eng => English
01:48:34 [INFO ] chs => 中文（简体）
01:48:34 [INFO ] cht => 中文（繁體）
01:48:34 [INFO ] jpn => 日本語
01:48:34 [INFO ] rus => Pyccĸий
01:48:34 [INFO ] spa => Español
01:48:34 [INFO ] pol => Polish
01:48:34 [INFO ] bra => Português-Brasil
01:48:34 [INFO ] kor => 한국어
01:48:34 [INFO ] ukr => Українська
01:48:34 [INFO ] deu => Deutsch
01:48:34 [INFO ] ltu => Lietuviškai
01:48:34 [INFO ] idn => Indonesia
01:48:34 [INFO ] cze => Czech
01:48:34 [INFO ] tur => Turkish
01:48:34 [INFO ] fin => Suomi
> eng
01:48:39 [INFO ] Loading nukkit.yml ...
01:48:39 [INFO ] Loading server.properties ...
01:48:39 [INFO ] Selected English (eng) as the base language
01:48:39 [INFO ] Starting Minecraft: BE server version v1.16.20
01:48:39 [INFO ] Selected Zlib Provider: 2 (cn.nukkit.utils.ZlibThreadLocal)
01:48:39 [INFO ] Opening server on 0.0.0.0:19132
01:48:39 [INFO ] This server is running Nukkit version git-4f24276 "" (API 1.0.11)
01:48:39 [INFO ] Nukkit is distributed under the LGPL License
01:48:42 [INFO ] Loading recipes...
01:48:42 [INFO ] Loaded 1507 recipes.
01:48:42 [INFO ] Successfully loaded 0 resource packs
01:48:43 [WARN ] Level "world" not found
01:48:43 [INFO ] Preparing level "world"
01:48:43 [INFO ] Preparing start region for level "world"
01:48:43 [WARN ] Level "nether" not found
01:48:43 [INFO ] No level called "nether" found, creating default nether level.
01:48:43 [INFO ] Preparing level "nether"
01:48:43 [INFO ] Preparing start region for level "nether"
01:48:43 [INFO ] Starting GS4 status listener
01:48:43 [INFO ] Setting query port to 19132
01:48:43 [INFO ] Query is running on 0.0.0.0:19132
01:48:43 [INFO ] Default game type: Survival Mode
01:48:43 [INFO ] Done (9.96s)! For help, type "help" or "?"

I am unable to connect to the server from my iPhone

I open up another terminal window ssh onto the Raspberry Pi and run the command

nc localhost 19132

And get no response (when I run the same for the ssh port (22) I get a response), so it looks like the server is not actually listening.

When I ctrl+c in the window 'running' the server I get the following response:

1:51:51 [INFO ] [CONSOLE: Stopping the server]
01:51:51 [INFO ] Unloading level "world"
> WARNING: An illegal reflective access operation has occurred
WARNING: Illegal reflective access by cn.nukkit.utils.IterableThreadLocal (file:/home/pi/nukkit/nukkit-1.0-SNAPSHOT.jar) to field java.lang.Thread.threadLocals
WARNING: Please consider reporting this to the maintainers of cn.nukkit.utils.IterableThreadLocal
WARNING: Use --illegal-access=warn to enable warnings of further illegal reflective access operations
WARNING: All illegal access operations will be denied in a future release
01:51:51 [INFO ] Unloading level "nether"
01:51:52 [INFO ] Stopping other threads

Any support on what is going wrong, would be most welcome. I have attempted 3 fresh Raspbian installs and all with the same outcome.

 

[Sleepybear]

Check your IPTables to make sure you opened UDP Port 19132

 

[CloudDog23]

Check your IPTables to make sure you opened UDP Port 19132

Many thanks for taking the time to respond.

I've looked at the IPTables and there are no ports open or closed. As SSH is working, and I am unable to get a response via "nc localhost 19132" I do not believe IPTables would be the problem

pi@raspberrypi-mc:~ $ sudo iptables -L -v
Chain INPUT (policy ACCEPT 0 packets, 0 bytes)
 pkts bytes target     prot opt in     out     source               destination         

Chain FORWARD (policy ACCEPT 0 packets, 0 bytes)
 pkts bytes target     prot opt in     out     source               destination         

Chain OUTPUT (policy ACCEPT 0 packets, 0 bytes)
 pkts bytes target     prot opt in     out     source               destination

 

[CloudDog23]

OK that IPTables was the hint needed.

Initially on checking the IPTable, I got an error, after Googling the solution to that error (rebooting because the original configuration is held open after upgrade) that error went away and I was able to see the configuration for IPTable.

I took a leap that a configuration was help open when ran nukkit for the first time, so I wiped everything and started again, but rebooting after update, upgrade and java install, before running nukkit for the first time.

I am now able to connect to the server.

I now have a

"Could not save player "xxx": java.io.FileNotFoundException: nullplayers/xxx.dat (No such file or directory)"

error, but, onwards and upwards.

 

[CloudDog23]

I am now able to connect to the server.

I now have a

"Could not save player "xxx": java.io.FileNotFoundException: nullplayers/xxx.dat (No such file or directory)"

error, but, onwards and upwards.

Creating a folder called "nullplayers" solved that issue.

 

[Sleepybear]

This bug was fixed in my last PR