Linux的systemctl命令详解、（永久）关闭SElinux和firewalld防火墙

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已于 2024-05-16 20:52:19 修改

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分类专栏： Linux 文章标签： linux 运维 centos selinux firewall防火墙

于 2023-01-06 13:50:59 首次发布

本文链接：https://blog.youkuaiyun.com/weixin_64334766/article/details/128577235

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一.systemctl命令详解

1.查看服务状态

（1）下载好服务

（2）查看状态systemctl status httpd，active为dead为无法使用状态

2.启动服务

（1）临时启动一次systemctl start httpd，active为running已启动服务可以使用

（2）开机自启动systemctl enable httpd

3.重启服务

4.停止服务

（1）临时停止一次systemctl stop httpd，已关闭

（2）永久禁用服务systemctl disable httpd

5.重载服务，重新加载服务的配置文件，需要服务是在开启状态

一.systemctl命令详解

1.查看服务状态

（1）下载好服务

[root@sulibao ~]# yum install -y httpd
Updating Subscription Management repositories.
Unable to read consumer identity

This system is not registered with an entitlement server. You can use subscription-manager to register.

Last metadata expiration check: 14:01:12 ago on Wed 11 Jan 2023 09:53:23 PM CST.
Package httpd-2.4.37-41.module+el8.5.0+11772+c8e0c271.x86_64 is already installed.
Dependencies resolved.
Nothing to do.
Complete!

（2）查看状态systemctl status httpd，active为dead为无法使用状态

[root@sulibao ~]# systemctl status httpd
● httpd.service - The Apache HTTP Server
   Loaded: loaded (/usr/lib/systemd/system/httpd.service; disabled; vendor pres>
   Active: inactive (dead)
     Docs: man:httpd.service(8)

2.启动服务

（1）临时启动一次systemctl start httpd，active为running已启动服务可以使用

[root@sulibao ~]# systemctl start httpd
[root@sulibao ~]# systemctl status httpd
● httpd.service - The Apache HTTP Server
   Loaded: loaded (/usr/lib/systemd/system/httpd.service; disabled; vendor pres>
   Active: active (running) since Thu 2023-01-12 11:58:03 CST; 11s ago
     Docs: man:httpd.service(8)
 Main PID: 8291 (httpd)
   Status: "Started, listening on: port 80"
    Tasks: 213 (limit: 65651)
   Memory: 55.4M
   CGroup: /system.slice/httpd.service
           ├─8291 /usr/sbin/httpd -DFOREGROUND
           ├─8307 /usr/sbin/httpd -DFOREGROUND
           ├─8308 /usr/sbin/httpd -DFOREGROUND
           ├─8309 /usr/sbin/httpd -DFOREGROUND
           └─8322 /usr/sbin/httpd -DFOREGROUND

Jan 12 11:57:52 sulibao systemd[1]: Starting The Apache HTTP Server...
Jan 12 11:58:03 sulibao httpd[8291]: AH00558: httpd: Could not reliably determi>
Jan 12 11:58:03 sulibao systemd[1]: Started The Apache HTTP Server.
Jan 12 11:58:13 sulibao httpd[8291]: Server configured, listening on: port 80
//显示你所做的操作

（2）开机自启动systemctl enable httpd

[root@sulibao ~]# systemctl enable httpd
Created symlink /etc/systemd/system/multi-user.target.wants/httpd.service → /usr/lib/systemd/system/httpd.service.
//为httpd服务创建了软链接

3.重启服务

systemctl restart httpd

[root@sulibao ~]# systemctl restart httpd

4.停止服务

（1）临时停止一次systemctl stop httpd，已关闭

[root@sulibao ~]# systemctl stop httpd
[root@sulibao ~]# systemctl status httpd
● httpd.service - The Apache HTTP Server
   Loaded: loaded (/usr/lib/systemd/system/httpd.service; enabled; vendor prese>
   Active: inactive (dead) since Thu 2023-01-12 12:03:50 CST; 10s ago
     Docs: man:httpd.service(8)
  Process: 8615 ExecStart=/usr/sbin/httpd $OPTIONS -DFOREGROUND (code=exited, s>
 Main PID: 8615 (code=exited, status=0/SUCCESS)
   Status: "Running, listening on: port 80"

Jan 12 12:02:02 sulibao systemd[1]: Starting The Apache HTTP Server...
Jan 12 12:02:17 sulibao httpd[8615]: AH00558: httpd: Could not reliably determi>
Jan 12 12:02:17 sulibao systemd[1]: Started The Apache HTTP Server.
Jan 12 12:02:27 sulibao httpd[8615]: Server configured, listening on: port 80
Jan 12 12:03:49 sulibao systemd[1]: Stopping The Apache HTTP Server...
Jan 12 12:03:50 sulibao systemd[1]: httpd.service: Succeeded.
Jan 12 12:03:50 sulibao systemd[1]: Stopped The Apache HTTP Server.

（2）永久禁用服务systemctl disable httpd

[root@sulibao ~]# systemctl disable httpd
Removed /etc/systemd/system/multi-user.target.wants/httpd.service.

5.重载服务，重新加载服务的配置文件，需要服务是在开启状态

[root@sulibao ~]# systemctl reload httpd
httpd.service is not active, cannot reload.
[root@sulibao ~]# systemctl restart httpd
[root@sulibao ~]# systemctl reload httpd

二.SElinux关闭

1.临时关闭

使用setenforce 0命令临时关闭SElinux

[root@sulibao ~]# setenforce 0
setenforce: SELinux is disabled

查看状态是否关闭

[root@sulibao ~]# getenforce 
Disabled

2.永久关闭

（1）修改配置文件/etc/selinux/config

这个文件有一个链接文件是/etc/sysconfig/selinux

[root@sulibao ~]# vim /etc/selinux/config

（2）将文件内SELINUX=XX这行改为 SELINUX=disabled或者SELINUX=permissive，然后保存退出，重启生效


# This file controls the state of SELinux on the system.
# SELINUX= can take one of these three values:
#     enforcing - SELinux security policy is enforced.
#     permissive - SELinux prints warnings instead of enforcing.
#     disabled - No SELinux policy is loaded.
SELINUX=disabled
# SELINUXTYPE= can take one of three values:
#     targeted - Targeted processes are protected,
#     minimum - Modification of targeted policy. Only selected processes are protected. 
#     mls - Multi Level Security protection.
SELINUXTYPE=targeted

也可以使用sed语句来更改：

sed -i 's/^SELINUX=.*/SELINUX=disabled/' /etc/selinux/config

（3）重启过后使用getenforce查看SElinux状态，为Disabled或permissive即可认为关闭成功

[root@sulibao ~]# getenforce 
Disabled

三.关闭防火墙（firewalld服务）

1.查看防火墙状态

systemctl status firewalld，active为running表示正在运行

[root@sulibao ~]# systemctl status firewalld
● firewalld.service - firewalld - dynamic firewall daemon
   Loaded: loaded (/usr/lib/systemd/system/firewalld.service; enabled; vendor preset: enabled)
   Active: inactive (dead)
     Docs: man:firewalld(1)
[root@sulibao ~]# systemctl restart firewalld
[root@sulibao ~]# systemctl status firewalld
● firewalld.service - firewalld - dynamic firewall daemon
   Loaded: loaded (/usr/lib/systemd/system/firewalld.service; enabled; vendor preset: enabled)
   Active: active (running) since Fri 2023-01-06 13:32:07 CST; 2s ago
     Docs: man:firewalld(1)
 Main PID: 28795 (firewalld)
    Tasks: 2
   CGroup: /system.slice/firewalld.service
           └─28795 /usr/bin/python2 -Es /usr/sbin/firewalld --nofork --nopid

Jan 06 13:32:06 sulibao systemd[1]: Starting firewalld - dynamic firewall daemon...
Jan 06 13:32:07 sulibao systemd[1]: Started firewalld - dynamic firewall daemon.
Jan 06 13:32:07 sulibao firewalld[28795]: WARNING: AllowZoneDrifting is enabled. This is considered an insecure configuration option. It will be removed in a ...ng it now.
Hint: Some lines were ellipsized, use -l to show in full.

2.关闭防火墙

systemctl stop firewalld 此次关闭，下次不关闭

systemctl disable firewalld 禁用，永久关闭

[root@sulibao ~]# systemctl stop firewalld
[root@sulibao ~]# systemctl disable firewalld
Removed symlink /etc/systemd/system/multi-user.target.wants/firewalld.service.
Removed symlink /etc/systemd/system/dbus-org.fedoraproject.FirewallD1.service.

查看firewalld服务状态，active为dead，此时已经永久关闭

[root@sulibao ~]# systemctl status firewalld
● firewalld.service - firewalld - dynamic firewall daemon
   Loaded: loaded (/usr/lib/systemd/system/firewalld.service; disabled; vendor preset: enabled)
   Active: inactive (dead)
     Docs: man:firewalld(1)