[systemd-devel] [systemd-nspawn] nginx: [emerg] open() "/dev/stderr" failed (6: No such device or address)

[Peter Paule]

> What happens if you use "dd" to write to /dev/stdout? Does that work,
> too? (i think that bash handles /dev/stderr specially when you use it
> with redirection, that's why I am asking).

I modified the unit file to use dd instead of nginx. I can reproduce the issue.
By mistake I forgot to add the "systemd-nspawn" call.

  [Unit]
  Description=Webservice for %I
  
  [Service]
  ExecStart=/usr/bin/dd if=/dev/zero of=/dev/stderr bs=1M count=5
  KillMode=process
  KillSignal=SIGINT
  SendSIGKILL=no

After that I started the service and checked its status:

  % root at localhost ~/tmp/centos-nginx/files/machines (git)-[master] # systemctl status nginx at example_com

    ● nginx at example_com.service - Webservice for example_com
       Loaded: loaded (/etc/systemd/system/nginx at .service; enabled; vendor preset: disabled)
       Active: failed (Result: exit-code) since Sun 2015-04-26 14:09:10 CEST; 1s ago
      Process: 5124 ExecStart=/usr/bin/dd if=/dev/zero of=/dev/stderr bs=1M count=5 (code=exited, status=1/FAILURE)
     Main PID: 5124 (code=exited, status=1/FAILURE)
    
    Apr 26 14:09:10 localhost systemd[1]: Started Webservice for example_com.
    Apr 26 14:09:10 localhost systemd[1]: Starting Webservice for example_com...
    Apr 26 14:09:10 localhost dd[5124]: /usr/bin/dd: failed to open ‘/dev/stderr’: No such device or address
    Apr 26 14:09:10 localhost systemd[1]: nginx at example_com.service: main process exited, code=exited, status=1/FAILURE
    Apr 26 14:09:10 localhost systemd[1]: Unit nginx at example_com.service entered failed state.
    Apr 26 14:09:10 localhost systemd[1]: nginx at example_com.service failed.

Thus the error seems to be not a problem of systemd-nspawn.