console-getty.service: don't start when /dev/console is missing

console-getty.service: don't start when /dev/console is missing

Create minimal image which runs systemd

   FROM rhel7.1
   RUN yum install -y /usr/bin/ps
   ENV container docker
   CMD [ "/usr/sbin/init" ]

When you run the container without -t, the process

   /sbin/agetty --noclear --keep-baud console 115200 38400 9600

is not happy and checking the journal in the container, there is a stream of

Mar 13 04:50:15 11bf07f59fff agetty[66]: /dev/console: No such file or directory
Mar 13 04:50:25 11bf07f59fff systemd[1]: console-getty.service holdoff time over, scheduling restart.
Mar 13 04:50:25 11bf07f59fff systemd[1]: Stopping Console Getty...
Mar 13 04:50:25 11bf07f59fff systemd[1]: Starting Console Getty...
Mar 13 04:50:25 11bf07f59fff systemd[1]: Started Console Getty.
Mar 13 04:50:25 11bf07f59fff agetty[67]: /dev/console: No such file or directory
Mar 13 04:50:35 11bf07f59fff systemd[1]: console-getty.service holdoff time over, scheduling restart.
Mar 13 04:50:35 11bf07f59fff systemd[1]: Stopping Console Getty...
Mar 13 04:50:35 11bf07f59fff systemd[1]: Starting Console Getty...
Mar 13 04:50:35 11bf07f59fff systemd[1]: Started Console Getty.
Mar 13 04:50:35 11bf07f59fff agetty[74]: /dev/console: No such file or directory
Mar 13 04:50:45 11bf07f59fff systemd[1]: console-getty.service holdoff time over, scheduling restart.
Mar 13 04:50:45 11bf07f59fff systemd[1]: Stopping Console Getty...
Mar 13 04:50:45 11bf07f59fff systemd[1]: Starting Console Getty...