SystemD JournalD不能禁用子进程输出

Question

我正在一个内核5.10.50的定制嵌入式Linux设备上运行SystemD版本的249.7+。我使用Podman 4.0.2与Docker一起运行几个容器。我遇到的问题是，podman系统服务中的“conmon”子进程重复了坞-组合进程生成的每个日志日志条目。我希望删除日志条目的conmon版本，并且只保留那些由生成的日志条目。

Journalctl显示的重复条目如下：

-- Journal begins at Sun 2012-01-01 00:02:21 UTC. --
Mar 30 17:06:15 device conmon[1625]: {"products":["Linux","Windows","Mac"]}
Mar 30 17:06:16 device sh[16648]: app1  | App1 endpoint hit ...
Mar 30 17:06:16 device sh[16648]: app3  | {"products":["Linux","Windows","Mac"]}
Mar 30 17:06:16 device sh[16648]: app2  | App2 endpoint hit ...
Mar 30 17:06:16 device sh[16648]: app1  | 10.89.0.3 - - [30/Mar/2022 17:06:15] "GET / HTTP/1.1" 200 -
Mar 30 17:06:16 device sh[16648]: app2  | Getting http://app1 ...
Mar 30 17:06:16 device sh[16648]: app2  | Status of GET: 200
Mar 30 17:06:16 device sh[16648]: app2  | Results of GET: {"products":["Linux","Windows","Mac"]}
Mar 30 17:06:16 device sh[16648]: app2  |
Mar 30 17:06:16 device sh[16648]: app2  | 10.89.0.4 - - [30/Mar/2022 17:06:15] "GET / HTTP/1.1" 200 -
Mar 30 17:06:21 device conmon[1558]: App2 endpoint hit ...
Mar 30 17:06:21 device conmon[1558]: Getting http://app1 ...
Mar 30 17:06:22 device sh[16648]: app1  | App1 endpoint hit ...
Mar 30 17:06:22 device sh[16648]: app2  | App2 endpoint hit ...
Mar 30 17:06:22 device sh[16648]: app1  | 10.89.0.3 - - [30/Mar/2022 17:06:22] "GET / HTTP/1.1" 200 -
Mar 30 17:06:22 device sh[16648]: app3  | {"products":["Linux","Windows","Mac"]}
Mar 30 17:06:22 device sh[16648]: app2  | Getting http://app1 ...
Mar 30 17:06:22 device sh[16648]: app2  | Status of GET: 200
Mar 30 17:06:22 device sh[16648]: app2  | Results of GET: {"products":["Linux","Windows","Mac"]}
Mar 30 17:06:22 device sh[16648]: app2  |
Mar 30 17:06:22 device sh[16648]: app2  | 10.89.0.4 - - [30/Mar/2022 17:06:22] "GET / HTTP/1.1" 200 -
Mar 30 17:06:22 device conmon[1393]: App1 endpoint hit ...
Mar 30 17:06:22 device conmon[1393]: 
Mar 30 17:06:22 device conmon[1393]: 10.89.0.3 - - [30/Mar/2022 17:06:22] "GET / HTTP/1.1" 200 -
Mar 30 17:06:22 device conmon[1558]: Status of GET: 200
Mar 30 17:06:22 device conmon[1558]: 
Mar 30 17:06:22 device conmon[1558]: Results of GET: {"products":["Linux","Windows","Mac"]}
Mar 30 17:06:22 device conmon[1558]: 
Mar 30 17:06:22 device conmon[1558]: 10.89.0.4 - - [30/Mar/2022 17:06:22] "GET / HTTP/1.1" 200 -
Mar 30 17:06:22 device conmon[1625]: {"products":["Linux","Windows","Mac"]}

conmon日志由podman.service的“conmon”子进程生成。

root@device:~# systemctl status podman
● podman.service - Podman API Service
     Loaded: loaded (8;;file://device/lib/systemd/system/podman.service^G/lib/systemd/system/podman.service8;;^G; enabled; vendor preset: enabled)
     Active: active (running) since Wed 2022-03-30 15:48:55 UTC; 1h 18min ago
TriggeredBy: ● podman.socket
       Docs: 8;;man:podman-system-service(1)^Gman:podman-system-service(1)8;;^G
   Main PID: 515 (podman)
      Tasks: 17 (limit: 495)
     Memory: 11.8M
        CPU: 2min 11.029s
     CGroup: /system.slice/podman.service
             ├─ 515 /usr/bin/podman --log-level=error system service --time=0
             ├─1391 /usr/bin/dnsmasq -u root --conf-file=/run/containers/cni/dnsname/docker-compose_host_internal_net/dnsmasq.conf
             ├─1393 /usr/bin/conmon --api-version 1 -c 6739cff6019d2f7e8f123d6fb02f163ec99ee73d322672c41d81f85d6218c66f -u 6739cff6019d2f7e8f123d6fb02f163ec99ee73d322672c41d81f85d6218c66f -r /usr/bin/crun -b /con>
             ├─1558 /usr/bin/conmon --api-version 1 -c ae34f69196a5d1b332f2f137942d3728c24bb41d06392b13dcfc7296f39b7936 -u ae34f69196a5d1b332f2f137942d3728c24bb41d06392b13dcfc7296f39b7936 -r /usr/bin/crun -b /con>
             └─1625 /usr/bin/conmon --api-version 1 -c b94e032b37a8690f847442ab9cdcf7b78aefab45231098d02c60b5f79e5c3474 -u b94e032b37a8690f847442ab9cdcf7b78aefab45231098d02c60b5f79e5c3474 -r /usr/bin/crun -b /con>

Mar 30 17:07:19 device conmon[1558]: App2 endpoint hit ...
Mar 30 17:07:19 device conmon[1558]: Getting http://app1 ...
Mar 30 17:07:20 device conmon[1393]: App1 endpoint hit ...
Mar 30 17:07:20 device conmon[1393]: 10.89.0.3 - - [30/Mar/2022 17:07:20] "GET / HTTP/1.1" 200 -
Mar 30 17:07:20 device conmon[1558]: Status of GET: 200
Mar 30 17:07:20 device conmon[1558]: 
Mar 30 17:07:20 device conmon[1558]: Results of GET: {"products":["Linux","Windows","Mac"]}
Mar 30 17:07:20 device conmon[1558]: 
Mar 30 17:07:20 device conmon[1558]: 10.89.0.4 - - [30/Mar/2022 17:07:20] "GET / HTTP/1.1" 200 -
Mar 30 17:07:20 device conmon[1625]: {"products":["Linux","Windows","Mac"]}

我已经尝试将podman.service StandardOutput和SystemD服务文件中的StandardErr重定向为null -但是conmon日志仍然显示在SystemD the中。

root@device:~# cat /lib/systemd/system/podman.service 
[Unit]
Description=Podman API Service
Requires=podman.socket
After=podman.socket
Documentation=man:podman-system-service(1)
StartLimitIntervalSec=0

[Service]
Environment=XDG_RUNTIME_DIR=
CPUWeight=1000
Type=exec
KillMode=process
StandardOutput=null
StandardError=null
Environment=LOGGING="--log-level=error"
#ExecStart=/bin/sh -c "/usr/bin/podman $LOGGING system service --time=0 1>/dev/null 2>/dev/null"
ExecStart=/usr/bin/podman $LOGGING system service --time=0

我怎样才能摆脱召集日志条目？谢谢。

Answer 1

尝试LogLevelMax=error，它只是将单元的所有日志记录限制为日志级别错误或更糟。至少对我来说，这解决了一个类似的问题:一个程序会用垃圾邮件发送日志。也许在这种情况下，它也会有所帮助，至少在某种意义上，它会抑制来自子进程的所有非错误消息。

这是相当自我解释的，但更多的细节，请查看手册中的systemd单位，它解释了这到底是做什么：https://www.freedesktop.org/software/systemd/man/systemd.exec.html。