我應該如何設置 systemd 服務來自動啟動伺服器並讓我將命令傳遞給它？

目標：

我正在嘗試讓 Minecraft 伺服器在 Fedora 上使用 systemd 在電腦啟動時執行。我需要滿足一些自我強加的標準才能正確管理我的伺服器：

1. 它必須以minecraft我使用 home dir 創建的系統使用者身份執行/opt/minecraft。我通過 ing 嘗試了這個adduser，然後添加了行User=minecraft和WorkingDirectory=/opt/minecraft/
2. 它必須是可擴展的並且可以與任意數量的伺服器一起工作。我通過使用模板服務嘗試了此操作，然後將WorkingDirectory行更改WorkingDirectory=/opt/minecraft/%i為讓我傳入一個目錄。
3. 我必須能夠以某種方式將命令傳遞給它。這是我堅持的那個。我曾嘗試使用插座單元，然後將其連接到/run/minecraft%I，但我無法讓它工作。如果您不熟悉 Minecraft 伺服器，他們有這個互動式控制台，您可以將命令傳遞到其中。過去，我使用tmux send過在會話中執行的伺服器tmux，但問題是它不會自動啟動並且感覺不優雅。

嘗試的解決方案：

/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

問題：

當我嘗試使用sudo systemctl start minecraft@1_17_1.service（我已經安裝了伺服器/opt/minecraft/1_17_1/）啟動伺服器時，它失敗了：

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.

這促使我執行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

並且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.

我看到它似乎對我的minecraft@.socket文件很生氣，所以我跑了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，問題似乎與我使用的管道的權限有關。

為了更好的衡量，我跑了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.

問題：

我究竟做錯了什麼？我在Google的第二、第三甚至第四頁上花了 4 個小時，但沒有任何解決方案。我在這裡不知所措，因此非常感謝任何和所有幫助。

我無法為您提供完整的答案，因為我無法重現該問題。但我試圖把一個最小可驗證的例子放在一起，並對故障排除有一些想法：

# /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

然後執行這個工作：

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.

您可能會在這裡遇到一些技巧：

1. 如果你systemctl stop minecraft@1_17_1.service，那麼這不會停止並行套接字。這意味著/run/minecraft1_17_1.stdin將繼續執行。事實上，如果你echo "hello" > /run/minecraft1_17_1.stdin，它會啟動你的服務。我可以想像，如果您正在對服務進行故障排除，舊的套接字可能會影響您的測試。我建議以下兩種選擇之一：

2. 用systemctl stop minecrat@1_17_1.{service,socket}它來阻止它，

3. 添加PartOf=minecraft@%i.service到[Unit]套接字的部分。這將導致它在服務停止時自動停止。

4. 您正在使用Restart=on-failure. 這對您的最終結果非常有用，但它可能會隱藏您最初的失敗。在進行故障排除時，請考慮暫時刪除它。然後當它失敗時，你會看到它失敗的最初原因。我的猜測是您在伺服器啟動時遇到了合法問題，但是您的套接字綁定到了第一個實例。然後每次重新啟動都無法在嘗試 ExecStart= 之前綁定到舊套接字，因此您永遠不會發現它最初失敗的原因。一定要停止服務和套接字，然後啟動它並立即檢查輸出。如果您的錯誤資訊不同，我不會感到驚訝。

5. 您將 minecraft 伺服器描述為具有 gui。這是可選的，並且突然取決於您的設置DISPLAY和XAUTHORITY設置。這引入了很多可以破壞的東西。考慮使用noguiin 選項呼叫您的服務，start.sh以消除導致初始失敗的可能原因。如果你真的很想要那個 gui，那麼你需要在你的腳本中設置DISPLAY和XAUTHORITY環境變數（但這不一定是最簡單的事情）。我建議至少在沒有 GUI 的情況下嘗試它，看看是否可以讓您的服務執行。

6. 您可能sudo systemctl daemon-reload在編輯文件時忘記執行。提醒一下，請務必執行此命令，以便 systemd 讀取每個單元的最新版本。

引用自：https://unix.stackexchange.com/questions/676199