Ubuntu安装code-server报错：Failed to enable unit: Unit file code-server.service does not exist.

## 简介

我的 Ubuntu 使用一键安装脚本安装 `code-server` 时，提示安装成功，但运行时报错：

```sh
Failed to enable unit: Unit file code-server.service does not exist.
```

## 详细过程

### 执行一键安装脚本

运行指令：
```sh
curl -fsSL https://code-server.dev/install.sh | sh -s -- --dry-run
```

运行后显示：
```bash
Ubuntu 24.04 LTS
Installing v4.89.1 of the amd64 deb package from GitHub.

+ mkdir -p ~/.cache/code-server
+ curl -#fL -o ~/.cache/code-server/code-server_4.89.1_amd64.deb.incomplete -C - https://github.com/coder/code-server/releases/download/v4.89.1/code-server_4.89.1_amd64.deb
+ mv ~/.cache/code-server/code-server_4.89.1_amd64.deb.incomplete ~/.cache/code-server/code-server_4.89.1_amd64.deb
+ sudo dpkg -i ~/.cache/code-server/code-server_4.89.1_amd64.deb

deb package has been installed.

To have systemd start code-server now and restart on boot:
  sudo systemctl enable --now code-server@$USER
Or, if you don't want/need a background service you can run:
  code-server

Deploy code-server for your team with Coder: https://github.com/coder/coder
```

可以看到提示信息让运行 `sudo systemctl enable --now code-server@$USER` 启动 `code-server` ，但运行时会报错：

```sh
# 运行
sudo systemctl enable --now code-server@$USER
# 报错
Failed to enable unit: Unit file [email protected] does not exist.

# 运行
sudo systemctl enable --now code-server
# 报错
Failed to enable unit: Unit file code-server.service does not exist.
```

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## 解决

尝试手动安装后不再报错：

```sh
# 设置要安装的版本：
export VERSION=4.89.1

# 运行
curl -fOL https://github.com/coder/code-server/releases/download/v$VERSION/code-server_${VERSION}_amd64.deb

# 运行
sudo dpkg -i code-server_${VERSION}_amd64.deb

# 设置自动启动
sudo systemctl enable --now code-server@$USER

# 会输出
Created symlink /etc/systemd/system/default.target.wants/[email protected] → /usr/lib/systemd/system/[email protected].
```

然后运行：

```sh
# 启动
sudo systemctl start code-server@$USER

# 此时可能出现警告
Warning: The unit file, source configuration file or drop-ins of [email protected] changed on disk. Run 'systemctl daemon-reload' to reload units.
```

如果出现警告，则执行

```sh
sudo systemctl daemon-reload

# 然后再启动
sudo systemctl start code-server@$USER
```

### 查看运行状态

启动成功后，可以查看服务运行状态：

```sh
sudo systemctl status code-server@$USER

● [email protected] - code-server
     Loaded: loaded (/usr/lib/systemd/system/[email protected]; enabled; preset: enabled)
     Active: active (running) since Sat 2024-06-01 13:56:36 UTC; 18min ago
   Main PID: 3698367 (node)
      Tasks: 22 (limit: 9352)
     Memory: 56.3M (peak: 72.6M)
        CPU: 1.469s
     CGroup: /system.slice/system-code\x2dserver.slice/[email protected]
             ├─3698367 /usr/lib/code-server/lib/node /usr/lib/code-server
             └─3698417 /usr/lib/code-server/lib/node /usr/lib/code-server/out/node/entry

Jun 01 13:56:36 dddx-hp systemd[1]: Started [email protected] - code-server.
Jun 01 13:56:36 dddx-hp code-server[3698367]: [2024-06-01T13:56:36.814Z] info  Wrote default config file to /home/dddx/.config/code-server/config.yaml
Jun 01 13:56:37 dddx-hp code-server[3698367]: [2024-06-01T13:56:37.231Z] info  code-server 4.89.1 effc6e95b4ad1c5ac5f9083ec06663ba4a2e005c
Jun 01 13:56:37 dddx-hp code-server[3698367]: [2024-06-01T13:56:37.233Z] info  Using user-data-dir /home/dddx/.local/share/code-server
Jun 01 13:56:37 dddx-hp code-server[3698367]: [2024-06-01T13:56:37.246Z] info  Using config file /home/dddx/.config/code-server/config.yaml
Jun 01 13:56:37 dddx-hp code-server[3698367]: [2024-06-01T13:56:37.246Z] info  HTTP server listening on http://127.0.0.1:8080/
Jun 01 13:56:37 dddx-hp code-server[3698367]: [2024-06-01T13:56:37.246Z] info    - Authentication is enabled
Jun 01 13:56:37 dddx-hp code-server[3698367]: [2024-06-01T13:56:37.246Z] info      - Using password from /home/dddx/.config/code-server/config.yaml
Jun 01 13:56:37 dddx-hp code-server[3698367]: [2024-06-01T13:56:37.246Z] info    - Not serving HTTPS
Jun 01 13:56:37 dddx-hp code-server[3698367]: [2024-06-01T13:56:37.246Z] info  Session server listening on /home/dddx/.local/share/code-server/code-server-ipc.sock

```