I am trying to set up a Minecraft server. However, the basic startup scripts provided do not fit my needs. I want a script that will:
Start a new screen running the jarfile and (pretty much) only the jarfile (so i can ^C it if needed without killing other things like screen or my gzip commands)
Gzip any logs that weren't gzipped automatically by the jarfile (for if/when i ^C'ed the server, or if it crashed)
Run a command with sudo to set the process in the first argument to a high priority (/usr/bin/oom-priority)
Run a http-server on the resource-pack directory in a different screen and send ^C to it when the server closes
I have these three commands. I run startserver to start the server.
startserver:
#!/bin/bash
set -m
cd /home/minecraftuser/server/
echo
screen -dm -S http-server http-server ./resource-pack
screen -dm -S my-mc-server startserver_command
(sleep 1; startserver_after) &
screen -S my-mc-server
startserver_command:
#!/bin/bash
set -m
cd /home/minecraftuser/server/
echo
java -Xmx768M -Xms768M -jar ./craftbukkit.jar $# &
env MC_PID=$! > /dev/null
(sleep 0.5; sudo /usr/bin/oom-priority $MC_PID) &
fg 1
echo
read -n 1 -p 'Press any key to continue...'
and startserver_after:
#!/bin/bash
cd /home/minecraftuser/server/
wait $MC_PID
find /home/minecraftuser/server/logs -type f -name "*.log" -print | while read file; do gzip $file &
done
screen -S http-server -p 0 -X stuff \^c\\r
Edit: When I run startserver, I get a command prompt then a bunch of gzip errors of files already existing (I am expecting these errors, but when I run startserver I'm supposed to get the java program). Somehow I am in a screen because when I do ^A d, I am brought to a new prompt.
Once I am out of the screen, screen -ls returns two instances of my-mc-server. One is a blank command prompt, the other is the server running successfully.
Edit 2: I changed startserver_command to remove the asterisk from env MC_PID=$! & (not needed there) and added it to (sleep 1; startserver_after) (makes it faster), redirected env line to /dev/null (removes entire environment listing at beginning of output). Still didn't fix the entire problem.
Instead of starting each screen session from the scripts, you can just use a custom .screenrc to specify some startup windows (and to run commands/scripts):
#$HOME/mc-server.screenrc
screen -t http-server 0 'startserver'
screen -t my-mc-server 1 'startserver_command'
screen -t gzip-logs 2 'startserver_after'
Then simply start screen (specifying the config file to use, if it's not the default ~/.screenrc)
screen -dm -c mc-server.screenrc
Related
I want to create a small startup script that does multiple things in a row in a screen.
The script starts a named, detached screen (screen -S discordbot -d -m works)
The user inside the script is changed (Neither screen -S discordbot -X "su discordbot", screen -S discordbot -X su discordbot, nor screen -S discordbot -d -m bash -c "su discordbot;" seems to work, or at least subsqeuent commands are not executed).
A cd folder change is exectuded.
A java jar or other script is started.
As I run multiple bots, the script needs to be able to do this in slight variation multiple times in a row. Any pointers on how this could be done?
The screen session that you start up will exit as soon as the process that you started exits.
This works, for instance:
$ screen -S discordbot -d -m bash
$ screen -ls
There is a screen on:
2948.discordbot (Detached)
1 Socket in <...>
As does this:
$ screen -S discordbot -d -m bin/discordbot.sh
Where bin/discordbot.sh looks like this:
#!/bin/sh
echo "Sleeping..."
sleep 10
/bin/echo -n "Hit enter to finish this script: "
read
The last two lines to prevent the screen from exiting prematurely. The other various things you want to do within that startup script should also work, assuming that you do this as root so that the su will work without prompting.
I have a problem where I am unable to start a screen session at boot using the rc.local file. The specific screen I am starting is for a spigot minecraft server.
This is my rc.local file:
#!/bin/sh -e
#
# rc.local
#
# This script is executed at the end of each multiuser runlevel.
# Make sure that the script will "exit 0" on success or any other
# value on error.
#
# In order to enable or disable this script just change the execution
# bits.
#
# By default this script does nothing.
/home/pi/Documents/bootlog.sh
/home/spigot1_12/startspigot.sh
exit 0
This is the startspigot.sh script (with chmod u+x):
#!/bin/bash
cd /home/spigot1_12
boot=$(date)
echo "Starting spigot server in screen \"minecraft\" # $boot " >> /home/pi/Documents/minecraftlog
screen -S minecraft java -Xms512M -Xmx1008M -jar /home/spigot1_12/spigot-1.12.jar nogui
The minecraftlog file does update at each boot, so the script is run.
When I run the command "sudo sh startspigot.sh", everything works perfectly. The screen is started and the minecraftlog file is updated. I can find the screen again with "sudo screen -ls"
At boot, however, both "sudo screen -ls" and "screen -ls" return no sockets.
What can be causing this? The only two users are "pi" and root.
Thanks in advance!
Starting a script in a new detached screen as current user (rc.local = root):
screen -dmS <session name> <command>, example:
screen -dmS screenName bash /home/user/run.sh
Starting a script from rc.local as user:
runuser -l user -c 'screen -dmS screenName bash /home/user/run.sh'
Running screen in detached mode (when you do not have active terminal, like in rc.local or crontab):
screen -dm -S <session name> <command>
-d -m Start screen in "detached" mode
-S When creating a new session, this option can be used to specify a meaningful name for the session.
Alright, so I have a .sh file that I run that will launch my server with the certain specifics that I'm looking for. It launches the server through screen into it's own screen. Here's the code for my run.sh file.
#!/bin/bash
# run.sh
# conversion of run.bat to shell script.
echo "Protecting srcds from random crashes"
echo "Now launching Garrys Mod RequiemRP"
sleep 5
screen -A -m -d -S gmserver ./srcds_run -console -game garrysmod +maxplayers 32 +map rp_downtown_v6 -autoupdate
echo "Server initialized. Type screen -x to resume"
Usually I use a batch file to do this, but I'm now using linux for my server hosting. Part of that batch file was if srcds (the server itself) were to crash, the run.bat file would restart the server automatically. I'm looking to do this with my run.sh file, but I'm unsure how to.
Perhaps you could make a service or script that will periodically check if the process is running. This will check if it's on and if it isn't, it will turn it on when executed.
#!/bin/bash
ps cax | grep srcds > /dev/null
if [ $? -eq 0 ]; then
exit
else
bash /path/to/run.sh
fi
I tested the command and it works. For my virtualized debian 9 system.
I'm writing a Linux shell script in which I need to start a new screen session, run a node.js server in the screen, then detach from the screen so that my server runs in the background.
Right now, these are the commands I run manually to do this:
screen
node server.js
[detach screen]
However, I need a way to automate this via the script, and if I just use the above commands in a shell script, it creates the screen and gets stuck there. How can I pass the "node server.js" command to the screen command?
EDIT:
Based on the suggested answer I have a script that works, except that I need to manually create a screen and detach from it before I run it. I tried adding screen -d -m as the first line to create a detached screen, but the script hangs after that line.
tempfile=$(mktemp)
indices=`tail -1 debug.log`
cat > $tempfile <<EOF
node server $indices
EOF
screen -X readbuf $tempfile
screen -X paste .
rm -f $tempfile
How can I create and detach a screen with the script?
This didn't work either:
screen
screen -d
It is as simple as this:
screen -md node server.js
This requires the command to run as a service (as it does), otherwise the screen stops immediately.
To optionally also set a name for the session (e.g. "session-name"):
screen -mdS session-name node server.js
You can then attach to the screen with:
screen -rd session-name
If you want to redirect all output to a file, you can do like this:
screen -mdS session-name bash -c 'node server.js &> output.log'
You can then monitor the output with e.g.:
tail -f output.log
You can list your running screens with:
screen -ls
or
screen -list
Example: Start a Python3 web server in a detached screen
Start a Python3 web server listening on port 8000 that serves files in the current directory, in a named
detached screen:
screen -mdS my-web-server python3 -mhttp.server
Or, with logging to a file:
screen -mdS my-web-server bash -c 'python3 -mhttp.server &> output.log'
For Python 2.x it looks like this:
screen -mdS my-web-server bash -c 'python -mSimpleHTTPServer &> output.log'
EDIT: Try this:
tempfile=$(mktemp)
cat > $tempfile <<EOF
node server.js
EOF
screen -S SessionName -X readbuf $tempfile; screen -RdS SessionName
screen -X paste .
rm -f $tempfile
It should create the temp file, create a screen called SessionName and runs the commands, then delete the temp file. Let me know if that works.
I've tried adding this to my crontab:
#reboot /root/startup
The "startup" file:
#!/bin/sh
svnserve -d -r /root/svnrepos/mainres
svnserve -d -r /root/svnrepos/mapres --listen-port=3691
screen -S mta ./mtaserver/mta-server > log1
screen -S mapmta ./mapserver/mta-server > log2
exit 0
Now svnserve commands run fine. The problem is with the screen command.
log1 and log2 files have the same content which is: Must be connected to a terminal.
What I'm trying to do is start the 2 executables on startup, and then later have a way to access them.
Is there a way to do this?
You want to add the following options to the 'screen' commands (e.g. before -S): -d -m
From the manpage:
-d -m Start screen in "detached" mode. This creates a new session but
doesn't attach to it. This is useful for system startup
scripts.