HackMD
Note: 偷吃步！？Ubuntu Server安裝GUI（xfce）
基於工作上（對，又是工作）用途，需要一組具備GUI的OS環境做實驗；想想就用手上現有的版本
來搞吧，還帶自動登入呢；套件就選擇最熟悉的xfce吧！
ーー理想是這樣，結果卡在lightdm（登入顯示管理器）的設定上；時間壓力的情況下就隨便建立
一個system daemon來運行xfce；反正能動就好了！對吧（！？）
- The image was uploaded to a note which you don't have access to
- The note which the image was originally uploaded to has been deleted
（對啊，牠在飛嘛）
Packages Installation
先安裝所需套件：
sudo apt update && upgrade -y
sudo apt install xfce4 -y
sudo apt install lightdm -y
sudo apt install xorg -y
Create system daemon service
使用指令建立daemon config：
vim /etc/systemd/system/startx-daemon.service
(startx是在文字界面下啟動X Window的指令，取名為startx-daemon是求一個直觀)
Details：
- The image was uploaded to a note which you don't have access to
- The note which the image was originally uploaded to has been deleted
[Unit]
Description：描述daemon，直白的說明用途是啟動X Window
After：確保在網路服務啟用後啟動
[Service]
User=root：指定以root啟動
WorkingDirectory=/root：指定在/root路徑下執行
ExecStart=/usr/bin/startx：daemon主要執行的內容，啟用X Window和執行檔路徑
Restart=always：當daemon崩潰時，自動重啟
Environment=DISPLAY=:0：無超時時間，也就是systemd會等待它完成。
StandardOutput=journal：標準輸出導至日誌系統journalctl -u startx-daemon.service
StandardError=journal：標準錯誤訊息導至日誌系統journalctl -u startx-daemon.service
[Install]
WantedBy=multi-user.target：這表示當系統進入"多重使用者狀態"（可以理解為執行級別3）時會啟用此daemon
賦予權限後接著啟用daemon:
chmod a+x /etc/systemd/system/startx-daemon.service
systemctl enable startx-daemon.service
Result & check status
成果：
- The image was uploaded to a note which you don't have access to
- The note which the image was originally uploaded to has been deleted
進入系統後可使用以下指令檢視運行狀態：
systemctl status startx-daemon.service
- The image was uploaded to a note which you don't have access to
- The note which the image was originally uploaded to has been deleted
