【转】怎么在rhel7中定义可以在系统启动时运行的脚本？

How to make custom script that runs automatically during boot up in RHEL7

https://access.redhat.com/solutions/1163283

 SOLUTION 已验证 - 已更新 2019年三月14日06:49 - 

English 

环境

• Red Hat Enterprise Linux 7

问题

• How to make custom script that runs automatically during boot up in RHEL7?
• In RHEL 5 and 6, we were using automatic startup feature of RHEL through /etc/rc.d/init.d.

决议

NOTE: Red Hat does not support implementation of custom scripts, including custom systemd startup scripts. This article is provided as a how-to and Red Hat will not troubleshoot any issues after the implementation of the steps provided here. For more information please see the Production Support Scope of Coverage
- Related solutions:
+ How to configure a command, script, or daemon to run after boot has finished in RHEL 7
+ How to allow a custom service script in RHEL7 to run in the foreground and accept user input
+ How to configure a systemd service in RHEL7 to run as a custom user or group

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1. Create a new service unit file at /etc/systemd/system/example.service1 with content based on the following

   Raw

   [Unit]
   Description=Example Service Script description goes here
   After=network.target
   
   [Service]
   Type=simple
   ExecStart=/usr/local/sbin/example.sh
   TimeoutStartSec=0
   
   [Install]
   WantedBy=default.target
   

   Optionally, consult footnotes for explanation:
   After=2 Type=3 TimeoutStartSec=4

2. Create the example shell script mentioned in the unit file's ExecStart directive, e.g., save the following to /usr/local/sbin/example.sh, making sure the file is executable

   Raw

   #!/bin/bash
   z=0
   for i in {1..5}; do 
       sleep 1m
       ((z++))
       wall example.sh: finished minute ${z}
   done
   wall example.sh: COMPLETELY FINISHED
   

3. Reload the systemd process to consider newly created example.service OR every time when example.service gets modified.

   Raw

   # systemctl daemon-reload
   

4. Enable the service and then reboot to test

   Raw

   # systemctl enable example.service
   
   # reboot
   

---

1. The unit file should be located in either /usr/lib/systemd/system/ or /etc/systemd/system/. See UNIT LOAD PATH section in  man systemd.unit. ↩

2. After=   If the script needs any other system facilities (networking, etc), modify the [Unit] section to include appropriate After=, Wants=, or Requires= directives, as described in:  man systemd.unit. ↩

3. Type=   Switch Type=simple for Type=idle in the [Service] section to delay execution of the script until all other jobs are dispatched (see  man systemd.service  for even more choices -- e.g., Type=oneshot can be useful in concert with other services). ↩

4. TimeoutStartSec=   When a service doesn't signal start-up completion within TimeoutStartSec, systemd considers the service failed; for long-running shell scripts it is essential to modify TimeoutStartSec or disable the timeout logic altogether as above, with TimeoutStartSec=0. See  man systemd.service  for more details. ↩