Ubuntu 18.04 设置开机启动脚本 rc.local systemd

ubuntu18.04不再使用initd管理系统，改用systemd。

ubuntu-18.04不能像ubuntu14一样通过编辑rc.local来设置开机启动脚本，通过下列简单设置后，可以使rc.local重新发挥作用。

1.建立rc-local.service文件

$ sudo vi /etc/systemd/system/rc-local.service

2.复制以下内容

[Unit]
Description=/etc/rc.local Compatibility
ConditionPathExists=/etc/rc.local
 
[Service]
Type=forking
ExecStart=/etc/rc.local start
TimeoutSec=0
StandardOutput=tty
RemainAfterExit=yes
SysVStartPriority=99
 
[Install]
WantedBy=multi-user.target

1) [Unit] 区块：启动顺序与依赖关系。

2) [Service] 区块：启动行为,如何启动，启动类型。

3) [Install] 区块，定义如何安装这个配置文件，即怎样做到开机启动。

3. 创建我们自定义的启动脚本（以后自己的脚本在这里面添加即可）

$ sudo vi /etc/rc.local

#!/bin/sh -e
#
# rc.local
#
# This script is executed at the end of each multiuser runlevel.
# Make sure that the script will "exit 0" on success or any other
# value on error.
#
# In order to enable or disable this script just change the execution
# bits.
#
# By default this script does nothing.
touch /home/xxx/`date +%Y-%m-%d`.log 
echo "`df`" >  /home/xxx/`date +%Y-%m-%d`.log  
echo "看到这行字，说明添加自启动脚本成功。" > /usr/local/test.log
exit 0

#!/bin/sh -e

-e 参数可以让脚本执行遇到错误就不往下执行

$ sudo chmod +x /etc/rc.local && sudo systemctl enable rc-local
Created symlink /etc/systemd/system/multi-user.target.wants/rc-local.service → /etc/systemd/system/rc-local.service.

启动服务，并检查服务（非必要）

$ sudo systemctl start rc-local.service
$ sudo systemctl status rc-local.service

● rc-local.service - /etc/rc.local Compatibility
   Loaded: loaded (/etc/systemd/system/rc-local.service; enabled; vendor preset:
  Drop-In: /lib/systemd/system/rc-local.service.d
           └─debian.conf
   Active: active (exited) since Fri 2019-01-25 09:31:07 CST; 9s ago
  Process: 17588 ExecStart=/etc/rc.local start (code=exited, status=0/SUCCESS)

Jan 25 09:31:07 SCHIPS systemd[1]: Starting /etc/rc.local Compatibility...
Jan 25 09:31:07 SCHIPS systemd[1]: Started /etc/rc.local Compatibility.

参考：

https://www.jianshu.com/p/79d24b4af4e5

https://www.cnblogs.com/defifind/p/9285456.html