Systemd Timer执行失败：Exec格式错误排查求助

环境与背景 #

在Proxmox 6.8.8-4环境中配置Systemd Timer，定时运行脚本将Obsidian库推送到私有Git仓库。该配置与已稳定运行数月的另一个Systemd Timer（触发scrutiny采集脚本）几乎一致，但手动运行脚本正常，Timer触发时出现EXEC格式错误。

同步脚本内容 #

#!/bin/bash  # 原脚本缺少该行，是核心问题之一

# 切换到Obsidian库目录，可根据实际路径修改
cd "/datastore/configs/obsidian/mikes_wiki/"

# 按.gitignore规则添加所有变更文件
git add .

# 带时间戳提交变更
git commit -m "Obsidian Vault Backup on  `date +'%d-%m-%Y %H:%M:%S'`"

# 推送到Git仓库
git push -u origin master

Systemd配置文件 #

obsidian_github_sync.service #

[Unit]
Description="Obsidian Github Sync systemd timer for Mikes Wiki"
Requires=obsidian_github_sync.timer

[Service]
Type=simple
ExecStart=/root/obsidian_gitpush.sh
User=root

obsidian_github_sync.timer #

[Unit]
Description="Timer for the obsidian_github_sync.service"

[Timer]
Unit=obsidian_github_sync.service
OnBootSec=5min
OnUnitActiveSec=62min

[Install]
WantedBy=timers.target

错误信息 #

$ systemctl status obsidian_github_sync.service
× obsidian_github_sync.service - "Obsidian Github Sync systemd timer for Mikes Wiki"
     Loaded: loaded (/etc/systemd/system/obsidian_github_sync.service; static)
     Active: failed (Result: exit-code) since Thu 2024-09-05 19:56:57 BST; 11s ago
   Duration: 646us
TriggeredBy: ● obsidian_github_sync.timer
    Process: 3202705 ExecStart=/root/obsidian_gitpush.sh (code=exited, status=203/EXEC)
   Main PID: 3202705 (code=exited, status=203/EXEC)
        CPU: 666us

Sep 05 19:56:57 flanders (tpush.sh)[3202705]: obsidian_github_sync.service: Failed to execute /root/obsidian_gitpush.sh: Exec format error
Sep 05 19:56:57 flanders systemd[1]: Started obsidian_github_sync.service - "Obsidian Github Sync systemd timer for Mikes Wiki".
Sep 05 19:56:57 flanders (tpush.sh)[3202705]: obsidian_github_sync.service: Failed at step EXEC spawning /root/obsidian_gitpush.sh: Exec format error
Sep 05 19:56:57 flanders systemd[1]: obsidian_github_sync.service: Main process exited, code=exited, status=203/EXEC
Sep 05 19:56:57 flanders systemd[1]: obsidian_github_sync.service: Failed with result 'exit-code'.

排查与解决步骤 #

1. 添加脚本shebang头
   systemd无法自动识别脚本解释器，必须在脚本第一行添加#!/bin/bash（若使用其他shell，可通过echo $SHELL查看路径后替换）。

2. 赋予脚本可执行权限
   执行命令添加执行权限：

   chmod +x /root/obsidian_gitpush.sh
   

3. 可选：修改systemd服务的ExecStart方式
   若不想修改脚本，可直接在service文件中指定shell执行脚本：

   ExecStart=/bin/bash /root/obsidian_gitpush.sh
   

4. 统一环境变量
   systemd运行时的环境变量可能与用户shell不一致，可在service的[Service]段添加完整PATH：

   Environment="PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"
   

   或在脚本中使用git的绝对路径（通过which git查看路径，比如/usr/bin/git add .）。

5. 重新加载配置并重启Timer
   修改完成后执行：

   systemctl daemon-reload
   systemctl restart obsidian_github_sync.timer
   

内容的提问来源于stack exchange，提问作者Mike Payne