Run from systemd unit file.

[Doty1154]

Hey I'm trying to run this from a systemd unit file on a up to date ubuntu server.
I previously used https://github.com/marcsello/minecraftd
So it's running from a specific user account and directory.
It sounds like the binary doesn't not like running from systemd for some reason. However if i run it manually from the "minecraft" user account in the /opt/minecraft folder your program works without issue(cool!)
Here's the issue i get for the systemd unit with debug systemd turned on:

Apr 02 02:59:29 minecraft systemd[1]: mc-server-wrapper.service: Will spawn child (service_enter_start): /opt/minecraft/.cargo/bin/mc-server-wrapper
Apr 02 02:59:29 minecraft systemd[1]: mc-server-wrapper.service: Passing 0 fds to service
Apr 02 02:59:29 minecraft systemd[1]: mc-server-wrapper.service: About to execute /opt/minecraft/.cargo/bin/mc-server-wrapper
Apr 02 02:59:29 minecraft systemd[1]: mc-server-wrapper.service: Forked /opt/minecraft/.cargo/bin/mc-server-wrapper as 1527
Apr 02 02:59:29 minecraft systemd[1]: mc-server-wrapper.service: Changed dead -> running
Apr 02 02:59:29 minecraft systemd[1]: mc-server-wrapper.service: Job 4668 mc-server-wrapper.service/start finished, result=done
Apr 02 02:59:29 minecraft systemd[1]: Started mc-server-wrapper.
░░ Subject: A start job for unit mc-server-wrapper.service has finished successfully
░░ Defined-By: systemd
░░ Support: http://www.ubuntu.com/support
░░
░░ A start job for unit mc-server-wrapper.service has finished successfully.
░░
░░ The job identifier is 4668.
Apr 02 02:59:29 minecraft systemd[1]: mc-server-wrapper.service: User lookup succeeded: uid=997 gid=998
Apr 02 02:59:29 minecraft systemd[1527]: mc-server-wrapper.service: Executing: /opt/minecraft/.cargo/bin/mc-server-wrapper
Apr 02 02:59:29 minecraft mc-server-wrapper[1527]: Error: Resource temporarily unavailable (os error 11)
Apr 02 02:59:29 minecraft systemd[1]: mc-server-wrapper.service: Child 1527 belongs to mc-server-wrapper.service.
Apr 02 02:59:29 minecraft systemd[1]: mc-server-wrapper.service: Main process exited, code=exited, status=1/FAILURE

Here is my systemd unit file, I've tried different types, using simple and then not specifying it. I also tried specifying kill mode/killsignal and not using these options.

[Unit]
Description=mc-server-wrapper
After=network-online.target

[Service]
Type=simple
ExecStart=/opt/minecraft/.cargo/bin/mc-server-wrapper
WorkingDirectory=/opt/minecraft
Restart=always
User=minecraft
Group=minecraft
KillMode=process
KillSignal=SIGINT

[Install]
WantedBy=multi-user.target

[Cldfire]

Hmm, interesting!

The best bit of information about what's going on is in this log line:

Apr 02 02:59:29 minecraft mc-server-wrapper[1527]: Error: Resource temporarily unavailable (os error 11)

Looking around the internet, I see a wide variety of possibilities for what that could mean.

• It could mean systemd is preventing my program from spawning processes (but I don't see TasksMax=1 in your config, so this seems unlikely): https://stackoverflow.com/questions/63596088/python-script-that-spawns-processes-fails-to-start-under-systemd
• It could mean the Minecraft server is already running on the port my program is trying to start it on: https://stackoverflow.com/questions/55028887/how-can-i-fix-resource-temporarily-unavailable-error-in-rust
• It could be a number of other things

Are there any logs from mc-server-wrapper itself you can share? Any kind of panic / backtrace information?

[Doty1154]

Hey, i know it's been a while since i posted. But. I got this working by simply using screen to open mc-server-wrapper in a active terminal session. I believe your package just exits once it sees that it's not running interactively(?) At least this is my theory.
I think long term maybe adding a -D flag or something where there isn't a tui but just a background process would be great in the future : )

Here's the config i'm using rn.. It doesn't exit appropriately so systemd ends up waiting like 2 minutes during shutdown and kills the process.. that sucks.. I'm not enough of a systemd wizard to figure out a better solution : p

[Unit]
Description=mc-server-wrapper
After=network-online.target


[Service]
Type=simple
ExecStart=screen -D -m /opt/minecraft/.cargo/bin/mc-server-wrapper
WorkingDirectory=/opt/minecraft
Restart=always
User=minecraft
Group=minecraft
KillMode=process
KillSignal=SIGCONT
RestartSec=30

[Install]
WantedBy=multi-user.target

[Cldfire]

Oh neat!

If I ever spend time on this project again I'll look into cleaning that up. I haven't played MC for a while so I don't have much of a reason to work on this tool.