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环境

  • Red Hat Enterprise Linux 7

问题

  • We have a custom service that starts a configuration script. We don't want the RHEL7 system to allow any logins (including ssh or local black & white ttys) until the script has finished. How?
  • How to disallow login in RHEL 7 until a SysV init script has finished?

决议

  1. Create a unit file for the service which must be started before logins are allowed
    The file should be located in either /usr/lib/systemd/system/ or /etc/systemd/system/1
    A service unit named MYSERVICE would have file named MYSERVICE.service
  2. Ensure the service definition2 meets AT LEAST the following conditions
    Raw
    [Unit] Before=sshd.service systemd-logind.service getty@tty1.service [Service] Type=oneshot ExecStart=/path/to/script "script args" "more script args" TimeoutStartSec=0 [Install] RequiredBy=sshd.service systemd-logind.service getty@tty1.service
  3. After modifying (or creating) the service unit file, run the following commands, even if MYSERVICE was already enabled
    Raw
    systemctl daemon-reload systemctl enable MYSERVICE.service
  4. Reboot and note that sshd and console login screens (not including serial) will fail to start until MYSERVICE has started