# 2. 创建应用脚本
# cat > /opt/mywebapp/app.py << 'EOF' #!/usr/bin/env python3 from http.server import HTTPServer, BaseHTTPRequestHandler class MyHandler(BaseHTTPRequestHandler): def do_GET(self): self.send_response(200) self.send_header('Content-type', 'text/html') self.end_headers() self.wfile.write(b'

Hello from MyWebApp!

‘)

if __name__ == ‘__main__’:
server = HTTPServer((‘0.0.0.0’, 8080), MyHandler)
print(‘Starting server on port 8080…’)
server.serve_forever()
EOF

# 3. 设置脚本执行权限
# chmod +x /opt/mywebapp/app.py

# 4. 创建服务配置文件
# cat > /etc/systemd/system/mywebapp.service << 'EOF' [Unit] Description=My Web Application After=network.target [Service] Type=simple User=nobody Group=nobody WorkingDirectory=/opt/mywebapp ExecStart=/usr/bin/python3 /opt/mywebapp/app.py Restart=on-failure RestartSec=5 StandardOutput=journal StandardError=journal SyslogIdentifier=mywebapp [Install] WantedBy=multi-user.target EOF # 5. 重新加载systemd配置 # systemctl daemon-reload # 6. 启动服务 # systemctl start mywebapp # 7. 查看服务状态 # systemctl status mywebapp ● mywebapp.service - My Web Application Loaded: loaded (/etc/systemd/system/mywebapp.service; disabled; vendor preset: disabled) Active: active (running) since Thu 2026-03-31 10:00:00 CST; 5s ago Main PID: 1234 (python3) Tasks: 2 (limit: 4915) Memory: 8.5M CGroup: /system.slice/mywebapp.service └─1234 /usr/bin/python3 /opt/mywebapp/app.py Mar 31 10:00:00 localhost systemd[1]: Started My Web Application. Mar 31 10:00:00 localhost mywebapp[1234]: Starting server on port 8080... # 8. 测试服务 # curl http://localhost:8080

Hello from MyWebApp!

# 9. 启用服务
# systemctl enable mywebapp
Created symlink /etc/systemd/system/multi-user.target.wants/mywebapp.service → /etc/systemd/system/mywebapp.service.

# 10. 查看服务日志
# journalctl -u mywebapp
— Logs begin at Thu 2026-03-31 09:00:00 CST. —
Mar 31 10:00:00 localhost systemd[1]: Started My Web Application.
Mar 31 10:00:00 localhost mywebapp[1234]: Starting server on port 8080…
Mar 31 10:00:05 localhost mywebapp[1234]: 127.0.0.1 – – [31/Mar/2026 10:00:05] “GET / HTTP/1.1” 200 –

[Service]
Type=forking
PIDFile=/run/nginx.pid
ExecStartPre=/usr/sbin/nginx -t
ExecStart=/usr/sbin/nginx
ExecReload=/bin/kill -s HUP $MAINPID
ExecStop=/bin/kill -s QUIT $MAINPID
PrivateTmp=true

[Install]
WantedBy=multi-user.target

# 2. 使用systemctl edit创建覆盖配置
# systemctl edit nginx

# 3. 添加自定义配置
# cat > /etc/systemd/system/nginx.service.d/override.conf << 'EOF' [Service] Restart=on-failure RestartSec=5 CPUQuota=50% MemoryLimit=512M EOF # 4. 重新加载systemd配置 # systemctl daemon-reload # 5. 查看合并后的配置 # systemctl cat nginx # /usr/lib/systemd/system/nginx.service [Unit] Description=nginx - high performance web server Documentation=http://nginx.org/en/docs/ After=network.target remote-fs.target nss-lookup.target Wants=network.target [Service] Type=forking PIDFile=/run/nginx.pid ExecStartPre=/usr/sbin/nginx -t ExecStart=/usr/sbin/nginx ExecReload=/bin/kill -s HUP $MAINPID ExecStop=/bin/kill -s QUIT $MAINPID PrivateTmp=true [Install] WantedBy=multi-user.target # /etc/systemd/system/nginx.service.d/override.conf [Service] Restart=on-failure RestartSec=5 CPUQuota=50% MemoryLimit=512M # 6. 重启服务 # systemctl restart nginx # 7. 查看服务状态 # systemctl status nginx ● nginx.service - nginx - high performance web server Loaded: loaded (/usr/lib/systemd/system/nginx.service; enabled; vendor preset: disabled) Drop-In: /etc/systemd/system/nginx.service.d └─override.conf Active: active (running) since Thu 2026-03-31 10:00:00 CST; 5s ago # 8. 删除覆盖配置 # rm -rf /etc/systemd/system/nginx.service.d/ # systemctl daemon-reload # systemctl restart nginx

# 1. 查看错误信息
# systemctl start myapp
Job for myapp.service failed because the control process exited with error code.
See “systemctl status myapp.service” and “journalctl -xe” for details.

# 2. 查看服务状态
# systemctl status myapp
● myapp.service – My Application Service
Loaded: loaded (/etc/systemd/system/myapp.service; disabled; vendor preset: disabled)
Active: failed (Result: exit-code) since Thu 2026-03-31 10:00:00 CST; 5s ago

Mar 31 10:00:00 localhost systemd[1]: Starting My Application Service…
Mar 31 10:00:00 localhost systemd[1234]: myapp.service: Failed to parse service type, ignoring: simplee
Mar 31 10:00:00 localhost systemd[1234]: myapp.service: Service has no ExecStart= setting, which is required for simple services. Refusing.
Mar 31 10:00:00 localhost systemd[1]: myapp.service: Control process exited, code=exited status=1
Mar 31 10:00:00 localhost systemd[1]: myapp.service: Failed with result ‘exit-code’.
Mar 31 10:00:00 localhost systemd[1]: Failed to start My Application Service.

# 3. 检查配置文件语法
# cat /etc/systemd/system/myapp.service
[Unit]
Description=My Application Service
After=network.target

[Service]
Type=simplee
ExecStart=/usr/local/bin/myapp.sh

[Install]
WantedBy=multi-user.target

# 4. 修复配置文件
# cat > /etc/systemd/system/myapp.service << 'EOF' [Unit] Description=My Application Service After=network.target [Service] Type=simple ExecStart=/usr/local/bin/myapp.sh [Install] WantedBy=multi-user.target EOF # 5. 重新加载systemd配置 # systemctl daemon-reload # 6. 启动服务 # systemctl start myapp # 7. 验证服务已启动 # systemctl status myapp ● myapp.service - My Application Service Loaded: loaded (/etc/systemd/system/myapp.service; disabled; vendor preset: disabled) Active: active (running) since Thu 2026-03-31 10:00:00 CST; 5s ago # 8. 预防措施 # - 检查配置文件语法 # - 使用systemd-analyze verify验证配置 # - 备份配置文件