Running the script as root, minecraft running under different user

[lmorgh]

Hello,

hopefully you can help me out, my minecraft server is ran by user "minecraft", and I'm trying to run the backup script as root. This results in "no screen session found". I'm a noob at managing my own server, so you can imagine I'm quite lost as far as figuring out the solution goes. I would be extremely grateful if you could point me in the right direction here. Should I just run the backup task as "minecraft" user, or should I somehow alter the command which runs the backup, or is there a better option yet?

Would really mean the world if you could help me out here.

[cgmckeever]

Run the command as the user, or set up the scheduled task to run as that user
Let me ask, HOW are you running it now , just manually or scheduled?

[lmorgh]

I was actually just trying to set up an automatic backup script, I don't have any backup solution atm.
I will try to set up a cron job with the minecraft user then, as described. I worry because just running the command as the user gives me this:

./backup.sh: line 505: /home/nomblox/minecraft/backups/2021-08-15_14-28-13.tar.gz: Permission denied
tar: Removing leading `/' from member names
FATAL: Archive command exited with nonzero exit code 141
du: cannot access '/home/nomblox/minecraft/backups/2021-08-15_14-28-13.tar.gz': No such file or directory
du: cannot access '/home/nomblox/minecraft/backups/2021-08-15_14-28-13.tar.gz': No such file or directory
rm: cannot remove '/home/nomblox/minecraft/backups/2021-08-15_14-28-13.tar.gz': No such file or directory

Unpacking the archive shows that not all files were backed up successfully (a lot is missing), and I have no idea what is causing it.

EDIT: also ingame chat says "[Backup] Backup was not saved!", if that helps.

[cgmckeever]

How are you launching Minecraft itself?

What does your backup.sh look like?

What does ls -la /home/nomblox/minecraft/backups/ output?

[cgmckeever]

Id first try to get the backup running manually as the user before fighting cron, there is somethng not right if as the user you are getting errors

[lmorgh]

I'm afraid I don't know how to easily copy the entire contents of the script, so I simply copied whatever was visible when opening it with nano. I haven't made any changes to the script itself though, if that's what you're wondering.

#!/usr/bin/env bash

# Minecraft server automatic backup management script
# https://github.com/nicolaschan/minecraft-backup
# MIT License
#
# For Minecraft servers running in a GNU screen, tmux, or RCON.
# For most convenience, run automatically with cron.

# Default Configuration
SCREEN_NAME="" # Name of the GNU Screen, tmux session, or hostname:port:password for RCON
SERVER_WORLDS=() # Server world directory
BACKUP_DIRECTORY="" # Directory to save backups in
MAX_BACKUPS=128 # -1 indicates unlimited
DELETE_METHOD="thin" # Choices: thin, sequential, none; sequential: delete oldest; thin: keep last 24 hourly, last 3$
COMPRESSION_ALGORITHM="gzip" # Leave empty for no compression
COMPRESSION_FILE_EXTENSION=".gz" # Leave empty for no compression; Precede with a . (for example: ".gz")
COMPRESSION_LEVEL=3 # Passed to the compression algorithm
ENABLE_CHAT_MESSAGES=false # Tell players in Minecraft chat about backup status
PREFIX="Backup" # Shows in the chat message
DEBUG=false # Enable debug messages
SUPPRESS_WARNINGS=false # Suppress warnings
RESTIC_HOSTNAME="" # Leave empty to use system hostname
LOCK_FILE="" # Optional lock file to acquire to ensure two backups don't run at once
LOCK_FILE_TIMEOUT="" # Optional lock file wait timeout (in seconds)
WINDOW_MANAGER="screen" # Choices: screen, tmux, RCON

# Other Variables (do not modify)
DATE_FORMAT="%F_%H-%M-%S"
TIMESTAMP=$(date +$DATE_FORMAT)

log-fatal () {
  echo -e "\033[0;31mFATAL:\033[0m $*"
}
log-warning () {
  echo -e "\033[0;33mWARNING:\033[0m $*"
}
debug-log () {
  if "$DEBUG"; then
    echo "$1"
  fi
}

while getopts 'a:cd:e:f:hH:i:l:m:o:p:qr:s:t:u:vw:x' FLAG; do
  case $FLAG in
    a) COMPRESSION_ALGORITHM=$OPTARG ;;
    c) ENABLE_CHAT_MESSAGES=true ;;
    d) DELETE_METHOD=$OPTARG ;;
    e) COMPRESSION_FILE_EXTENSION=".$OPTARG" ;;
    f) TIMESTAMP=$OPTARG ;;
    h) echo "Minecraft Backup"
       echo "Repository: https://github.com/nicolaschan/minecraft-backup"
       echo "-a    Compression algorithm (default: gzip)"
       echo "-c    Enable chat messages"
       echo "-d    Delete method: thin (default), sequential, none"
       echo "-e    Compression file extension, exclude leading \".\" (default: gz)"
       echo "-f    Output file name (default is the timestamp)"
                                         [ File 'backup.sh' is unwritable ]

The command ouput shows the couple of times I tried running the command, which produced some kind of archive every time, but the archives are incomplete.

minecraft@sd-150741:~$ ls -la /home/nomblox/minecraft/backups/
total 321688
drwxr-xr-x 2 root      root           4096 Aug 15 12:31 .
drwxrwxr-x 5 minecraft minecraft      4096 Aug 15 12:12 ..
-rw-r--r-- 1 root      root       81412096 Aug 15 12:18 2021-08-15_12-18-01.tar.gz
-rw-r--r-- 1 root      root      152436736 Aug 15 12:19 2021-08-15_12-19-32.tar.gz
-rw-r--r-- 1 root      root       32292864 Aug 15 12:23 2021-08-15_12-23-57.tar.gz
-rw-r--r-- 1 root      root       25542656 Aug 15 12:24 2021-08-15_12-24-15.tar.gz
-rw-r--r-- 1 root      root       37715968 Aug 15 12:31 2021-08-15_12-31-02.tar.gz

And yes, I agree that just sorting out the manual backup first is the way to go before tackling cron. I don't seem to be doing a great job of it though, lol.

[cgmckeever]

so, you need to take a few steps back. Those backup files as root came from somewhere and are not owned by the minecraft user. I would almost say delete them ...

Maybe Im doing something wrong, or in my own little way, but I cant just run the backup script without commands (That is why I asked you what backup/sh was, because I thought it was your script that. called backup) .. for example, I run mine as

backups=PATH/TO/BACKUPS
minecraft=PATH/TO/MINECRAFT

$backups/backup.sh -c -i $minecraft/world -o $backups/world -s minecraft -d sequential -m 30

also . how are you starting minecraft?

[cgmckeever]

Here are my notes that I use to set up minecraft all the way to backing up ..Im sure there are some holes my brain fills in, I think this is for debian flavor linux

https://github.com/cgmckeever/notes-and-such/tree/master/minecraft

[cgmckeever]

Is this your minecraft executable directory? /home/nomblox/minecraft/ ... I'd suggest, for sanity to move the backups out of there and leave that only for the executable minecraft files and not pollute it .. I think also is nomblox is some user and you are running things as minecraft you got some weird things going on .. those are home directories, you should never really cross user them .. but thats my opinion here

[lmorgh]

I'm the first to admit I had no clue what I was doing when setting up my server - I purchased a dedi, main purpose being mincraft server. I read through several tutorials, some were pretty outdated, some were for different linux distros (I use debian), so the result was a mix of everything. I read that it's crucial for security that you create a separate user for every service (not sure if service is the right word here) you run on your machine. So I sort of tried doing that. Looking back, 95% of my problems I encountered doing various things were related to users and permissions. So I'm pretty sure I funked something up along the way. My understanding of things is such:

• root is root
• nomblox I think is the user I made when setting up things (installing debian through my dedi provider website) and seemingly serves no real purpose except for messing with my permission structure. Oh, it allows me to ftp connect via Filezilla at least.
• minecraft was the user I created for the server (but put all files in the /nomblox folder for some reason, because somehow I thought it would be the best thing to do)

It's hard for me as I don't have any pre-existing server admin knowledge, I sort of been learning as I go, and a lot of tutorials and documentation is just gibberish to me, as it's simply too advanced for me to grasp. I'm not giving up tho, just wanted to shed some light onto why my setup is such a mess. Then on top of everything I'm setting up a website not related to minecraft on the same dedi machine, so I would be shooting myself in the leg if I installed debian from scratch and tried again (which I have considered doing).

Now back to the topic: I must have created those archives when running the command as root, meaning that it did something, but not the best job, as the archives are incomplete. Also meaning that running the command as minecraft user did nothing, as there are no archives from that user.

My server is located under /home/nomblox/minecraft/server-1, so the backup folder isn't a part of it.

I run minecraft with this script:

screen -d -m -S Minecraft ./startserver.sh

which in turn runs this script I picked up somewhere online:

JAR=paper.jar
MAXRAM=10G
MINRAM=10G
TIME=20


while [ true ]; do
        java -Xmx$MAXRAM -Xms$MINRAM -XX:+UseG1GC -XX:+ParallelRefProcEnabled -XX:MaxGCPauseMillis=200 -XX:+UnlockEx$
    if [[ ! -d "exit_codes" ]]; then
        mkdir "exit_codes";
    fi
    if [[ ! -f "exit_codes/server_exit_codes.log" ]]; then
        touch "exit_codes/server_exit_codes.log";
    fi
    echo "[$(date +"%d.%m.%Y %T")] ExitCode: $?" >> exit_codes/server_exit_codes.log
    echo "----- Press enter to prevent the server from restarting in $TIME seconds -----";
    read -t $TIME input;
    if [ $? == 0 ]; then
        break;
    else
        echo "------------------- SERVER RESTARTS -------------------";
    fi
done

Again the code was cut off in that java -Xmx line, as I just copied it in nano, it's the Aikar's flags that make the line so long.

All this mess makes my head hurt. What do you suggest I do? A part of me wants to start over, but I'm not sure I can do a better job, and thinking of all the hours I spent trying to make everything work is just... waaaaaa.

[cgmckeever]

you run this as the minecraft user?

screen -d -m -S Minecraft ./startserver.sh

[lmorgh]

Yes.

[cgmckeever]

This is what I would do ..

stop minecraft from running

As root -

• move the minecraft executable directory into the minecraft user folder

Switch to the minecraft user

• verify you can start minecraft and it works as expect
• make a backup directory outside of minecraft directory (one level up from it is fine)
• Manually kick off the backup .. see what happens

[cgmckeever]

I re-read your steps, I dont think you are as far off as you feel .. you are just tripping up on a few things ..
you can probably unwind this with a deep breathe, some re-org, and maybe a slight hit with a hammer ... just to get it going

[lmorgh]

I created the minecraft user without the home folder. Does that change anything?

[cgmckeever]

yes .. but you can either

• create the home directories for that user via root (there is a command that will handle it)
• put the minecraft directory in /opt/minecraft and make sure to chown -R minecraft.minecraft /opt/minecraft