1. 查看centos版本

cat /etc/redhat-release 

2. 安装docker前先关掉firewalld防火墙

systemctl stop firewalld

3. 禁止开机启动firewalld防火墙

systemctl disable firewalld

4.关闭seclinux，重启 .

getenforce
//查看
cat /etc/selinux/config

永久关闭 selinux

修改selinux的配置文件，重启后生效。

1. 打开 selinux 配置文件

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

2. 修改 selinux 配置文件
   将SELINUX=enforcing改为SELINUX=disabled，保存后退出

# 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=enforcing
# SELINUXTYPE= can take one of three two values:
#     targeted - Targeted processes are protected,
#     minimum - Modification of targeted policy. Only selected processes are protected. 
#     mls - Multi Level Security protection.
SELINUXTYPE=targeted

此时获取当前selinux防火墙的安全策略仍为Enforcing，配置文件并未生效。

[root@localhost ~]# getenforce
Enforcing

3. 重启

[root@localhost ~]# reboot

4. 验证

[root@localhost ~]# /usr/sbin/sestatus
SELinux status:                 disabled

[root@localhost ~]# getenforce
Disabled