Cfxtrjtrk

I am trying to properly setup my minecraft server with systemd so that it correctly determines the main PID for the process. I have the following systemd service unit:

[Unit]

Description=Minecraft Server

After=network.target



[Service]

User=minecraft

Group=minecraft



WorkingDirectory=/srv/minecraft



ProtectSystem=full

ProtectHome=true



Type=forking



ExecStartPre=/srv/minecraft/mc_server.sh setup

ExecStart=/srv/minecraft/mc_server.sh start



PIDFile=/srv/minecraft/mc.pid



ExecStop=/srv/minecraft/mc_server.sh stop





[Install]

WantedBy=multi-user.target

When I attempt to start the service, I get this error message (the main issue being the "failed to parse PID from file" part):

minecraft.service - Minecraft Server

   Loaded: loaded (/etc/systemd/system/minecraft.service; enabled; vendor preset: enabled)

   Active: failed (Result: timeout) since Wed 2018-11-28 12:57:03 PST; 6min ago

  Process: 9611 ExecStart=/srv/minecraft/mc_server.sh start (code=exited, status=0/SUCCESS)

  Process: 9591 ExecStartPre=/srv/minecraft/mc_server.sh setup (code=exited, status=0/SUCCESS)

 Main PID: 5213 (code=exited, status=0/SUCCESS)



Nov 28 12:55:32 xxx mc_server.sh[9591]: No Session found.  Creating and configuring.

Nov 28 12:55:32 xxx systemd[1]: minecraft.service: Found left-over process 9607 (tmux: server) in control group while starting unit. Ignoring.

Nov 28 12:55:32 xxx  systemd[1]: This usually indicates unclean termination of a previous run, or service implementation deficiencies.

Nov 28 12:55:32 xxx  systemd[1]: minecraft.service: Found left-over process 9608 (bash) in control group while starting unit. Ignoring.

Nov 28 12:55:32 xxx  systemd[1]: This usually indicates unclean termination of a previous run, or service implementation deficiencies.

Nov 28 12:55:32 xxx  mc_server.sh[9611]: Minecraft server successfully started

Nov 28 12:55:32 xxx  systemd[1]: minecraft.service: Failed to parse PID from file /srv/minecraft/mc.pid: Invalid argument

Nov 28 12:57:02 xxx  systemd[1]: minecraft.service: Start operation timed out. Terminating.

Nov 28 12:57:03 xxx  systemd[1]: minecraft.service: Failed with result 'timeout'.

Nov 28 12:57:03 xxx  systemd[1]: Failed to start Minecraft Server.

I'm not sure what this error means or how to resolve it. If I remove the PIDfile= option then it works, but lists the tmux process as the main PID and therefore doesn't record output from the java process in the logs. I also just noticed that it's not actually writing the PID to mc.pid. When running the script directly it does write the PID correctly.

Here is the contents of "mc_server.sh start", which is how I'm starting the server and creating the PID file (note that the tmux session is created during "mc_server.sh setup"):

/usr/bin/tmux send-keys -t minecraft '/usr/bin/java -server -Xmx2048M -Xms1024M -jar /srv/minecraft/minecraft_server.jar nogui' C-m && 

/usr/bin/pgrep -u minecraft -f minecraft_server.jar > /srv/minecraft/mc.pid