我应该如何设置一个systemd服务来自动启动服务器并让我将命令传递给它呢？

Question

目标：

我正试着让一个“我的世界”服务器在Fedora上运行在计算机引导系统上。我有一些自我强加的标准，我需要满足这些标准才能正确地管理我的服务器(S)：

1. 它必须以我用home dir /opt/minecraft创建的minecraft系统用户的身份运行。我尝试使用addusering，然后添加行User=minecraft和WorkingDirectory=/opt/minecraft/。
2. 它必须具有可伸缩性，并且可以处理任意数量的服务器。我尝试使用模板服务，然后将WorkingDirectory行更改为WorkingDirectory=/opt/minecraft/%i，让我在目录中传递。
3. 我必须能以某种方式将命令传递给它。这是我被困在上面的那个。我尝试过使用套接字单元，然后将其连接到/run/minecraft%I，但我一直无法让它工作。如果您不熟悉“我的世界”服务器，它们有一个交互式控制台，您可以将命令传递到其中。过去，我在运行在tmux send会话中的服务器时使用过tmux，但问题是它不会自动启动，而且感觉不优雅。

尝试解决方案：

/usr/local/lib/systemd/system/minecraft@.service：

[Unit]
Description=Minecraft server: %i

# only run after networking is ready
After=network-online.target
Wants=network-online.target

[Service]
Type=simple

# restart if the server crashes
Restart=on-failure
RestartSec=5s

# set the input and outputs to a socket unit and the journal resp.
Sockets=minecraft@%i.socket
StandardInput=socket                     
StandardOutput=journal
StandardError=journal

# set the user and directory to the correct values
User=minecraft
WorkingDirectory=/opt/minecraft/%i/

# run the start script for the specified server
ExecStart=/bin/bash /opt/minecraft/%i/start.sh

[Install]
WantedBy=default.target

/usr/local/lib/systemd/system/minecraft@.socket：

[Unit]
Description=Socket for Minecraft server: %i

[Socket]
# listen to a pipe for input
ListenFIFO=%t/minecraft%I.stdin

Service=minecraft@%i.service

问题：

当我尝试用sudo systemctl start minecraft@1_17_1.service启动服务器(我在/opt/minecraft/1_17_1/中安装了服务器)时，它失败了：

Job for minecraft@1_17_1.service failed because of unavailable resources or another system error.
See "systemctl status minecraft@1_17_1.service" and "journalctl -xeu minecraft@1_17_1.service" for details.

这促使我运行systemctl status minecraft@1_17_1.service：

● minecraft@1_17_1.service - Minecraft server: 1_17_1
     Loaded: loaded (/usr/local/lib/systemd/system/minecraft@.service; enabled; vendor preset: disabled)
     Active: activating (auto-restart) (Result: resources) since Thu 2021-11-04 14:37:27 EDT; 163ms ago
TriggeredBy: × minecraft@1_17_1.socket
        CPU: 0

还有journalctl -xeu minecraft@1_17_1.service

Nov 04 14:51:01 riley-fedora systemd[1]: minecraft@1_17_1.service: Got no socket.
Nov 04 14:51:01 riley-fedora systemd[1]: minecraft@1_17_1.service: Failed to run 'start' task: Invalid argument
Nov 04 14:51:01 riley-fedora systemd[1]: minecraft@1_17_1.service: Failed with result 'resources'.
░░ Subject: Unit failed
░░ Defined-By: systemd
░░ Support: https://lists.freedesktop.org/mailman/listinfo/systemd-devel
░░ 
░░ The unit minecraft@1_17_1.service has entered the 'failed' state with result 'resources'.
Nov 04 14:51:01 riley-fedora systemd[1]: Failed to start Minecraft server: 1_17_1.
░░ Subject: A start job for unit minecraft@1_17_1.service has failed
░░ Defined-By: systemd
░░ Support: https://lists.freedesktop.org/mailman/listinfo/systemd-devel
░░ 
░░ A start job for unit minecraft@1_17_1.service has finished with a failure.
░░ 
░░ The job identifier is 55890 and the job result is failed.

我看到它似乎对我的minecraft@.socket文件很生气，所以我运行了systemctl status minecraft@1_17_1.socket：

× minecraft@1_17_1.socket - Socket for Minecraft server: 1_17_1
     Loaded: loaded (/usr/local/lib/systemd/system/minecraft@.socket; static)
     Active: failed (Result: resources)
   Triggers: ● minecraft@1_17_1.service
     Listen: /run/minecraft1_17_1.stdin (FIFO)

Nov 04 14:52:35 riley-fedora systemd[1]: minecraft@1_17_1.socket: Failed with result 'resources'.
Nov 04 14:52:35 riley-fedora systemd[1]: Failed to listen on Socket for Minecraft server: 1_17_1.
Nov 04 14:52:41 riley-fedora systemd[1]: minecraft@1_17_1.socket: Failed to open FIFO /run/minecraft1_17_1.stdin: Permission denied
Nov 04 14:52:41 riley-fedora systemd[1]: minecraft@1_17_1.socket: Failed to listen on sockets: Permission denied
Nov 04 14:52:41 riley-fedora systemd[1]: minecraft@1_17_1.socket: Failed with result 'resources'.
Nov 04 14:52:41 riley-fedora systemd[1]: Failed to listen on Socket for Minecraft server: 1_17_1.
Nov 04 14:52:46 riley-fedora systemd[1]: minecraft@1_17_1.socket: Failed to open FIFO /run/minecraft1_17_1.stdin: Permission denied
Nov 04 14:52:46 riley-fedora systemd[1]: minecraft@1_17_1.socket: Failed to listen on sockets: Permission denied
Nov 04 14:52:46 riley-fedora systemd[1]: minecraft@1_17_1.socket: Failed with result 'resources'.
Nov 04 14:52:46 riley-fedora systemd[1]: Failed to listen on Socket for Minecraft server: 1_17_1.

因此，这个问题似乎与我所使用的管道的权限有关。

为了更好的衡量，我运行了journalctl -xeu minecraft@1_17_1.socket

Nov 04 14:52:46 riley-fedora systemd[1]: minecraft@1_17_1.socket: Failed to open FIFO /run/minecraft1_17_1.stdin: Permission denied
Nov 04 14:52:46 riley-fedora systemd[1]: minecraft@1_17_1.socket: Failed to listen on sockets: Permission denied
Nov 04 14:52:46 riley-fedora systemd[1]: minecraft@1_17_1.socket: Failed with result 'resources'.
░░ Subject: Unit failed
░░ Defined-By: systemd
░░ Support: https://lists.freedesktop.org/mailman/listinfo/systemd-devel
░░ 
░░ The unit minecraft@1_17_1.socket has entered the 'failed' state with result 'resources'.
Nov 04 14:52:46 riley-fedora systemd[1]: Failed to listen on Socket for Minecraft server: 1_17_1.
░░ Subject: A start job for unit minecraft@1_17_1.socket has failed
░░ Defined-By: systemd
░░ Support: https://lists.freedesktop.org/mailman/listinfo/systemd-devel
░░ 
░░ A start job for unit minecraft@1_17_1.socket has finished with a failure.
░░ 
░░ The job identifier is 58598 and the job result is failed.

问题：

我做错了什么？我花了4个小时在谷歌的第二页、第三页、甚至第四页上，没有任何解决方案。我在这里不知所措，所以我们非常感谢所有的帮助。

Answer 1

我没有给你一个完整的答案，因为我不能重现这个问题。但是，我尝试将一个最小可验证的示例放在一起，并对故障排除提出了一些想法：

# /etc/systemd/system/sockinst@.service
[Service]
ExecStart=cat -
User=stew
Sockets=sockinst@%i.socket
StandardInput=socket
StandardOutput=journal
StandardError=journal

# /etc/systemd/system/sockinst@.socket
[Socket]
ListenFIFO=%t/sockinst%I.stdin
Service=sockinst@%i.service

然后运行此操作：

stew /etc/systemd/system $ systemctl start sockinst@1_1.service
stew /etc/systemd/system $ echo "Hello" > /run/sockinst1_1.stdin 
stew /etc/systemd/system $ systemctl status sockinst@1_1.{service,socket}
● sockinst@1_1.service - Testing instanced sockets 1_1
     Loaded: loaded (/etc/systemd/system/sockinst@.service; static)
     Active: active (running) since Fri 2021-11-05 10:35:41 CET; 37s ago
TriggeredBy: ● sockinst@1_1.socket

systemd[1]: Started Testing instanced sockets 1_1.
cat[11623]: Hello

● sockinst@1_1.socket - Socket for instance 1_1
     Loaded: loaded (/etc/systemd/system/sockinst@.socket; static)
     Active: active (running) since Fri 2021-11-05 10:35:41 CET; 37s ago
   Triggers: ● sockinst@1_1.service
     Listen: /run/sockinst1_1.stdin (FIFO)

systemd[1]: Listening on Socket for instance 1_1.

在这里，您可能会遇到一些技巧：

1. 如果您使用systemctl stop minecraft@1_17_1.service，那么这不会停止并行套接字。这意味着/run/minecraft1_17_1.stdin将继续运行。事实上，如果您使用echo "hello" > /run/minecraft1_17_1.stdin，它将启动您的服务。我可以想象，如果您正在对您的服务进行故障排除，一个旧的套接字可能会影响您的测试。我建议两种选择之一：
   1. 用systemctl stop minecrat@1_17_1.{service,socket}阻止它，
   2. 将PartOf=minecraft@%i.service添加到套接字的[Unit]部分。这将导致它在服务停止时自动停止。

2. 您正在使用Restart=on-failure。这对你的最终结果很好，但它可能掩盖了你最初的失败。在进行故障排除时，请考虑暂时删除此选项。当它失败时，你会看到它失败的最初原因。我的猜测是，服务器启动存在合法问题，但是套接字被绑定到第一个实例。然后，每次重新启动都无法在尝试ExecStart=之前绑定到旧套接字，因此从一开始就找不到它最初失败的原因。确保停止服务和套接字，然后启动它并立即检查输出。如果你的错误信息不一样，我也不会感到惊讶。
3. 你把我的服务器描述为有一个gui。这是可选的，并且突然取决于设置您的DISPLAY和XAUTHORITY之类的内容。那会带来很多东西会坏掉。考虑使用nogui选项在start.sh中调用您的服务，以消除导致初始故障的可能原因。如果您真的想要这个gui，那么您需要在脚本中设置DISPLAY和XAUTHORITY环境变量(但这不一定是最简单的事情)。我建议至少在没有GUI的情况下试一试，看看这样是否能使您的服务运行。
4. 您可能在编辑文件时忘记运行sudo systemctl daemon-reload。提醒您，一定要运行这个程序，以便systemd读取每个单元的最新版本。