Centos7 database connection using 127.0.0.1 Report permission denied, use localhost to report no such file or directory__ database

After installing the lamp environment, test the database connection.

When host uses 127.0.0.1, the error is: (hy000/2002): Permission denied.

After replacing the host with localhost, it also complains: sqlstate[hy000] [2002] No such file or directory.

The final discovery is that SELinux is not turned off, and SELinux is enabled by default after CentOS7 is installed.

[Root@rdo ~]# sestatus  
SELinux Status:                 enabled  
SELINUXFS mount:                /sys/fs/selinux SELinux  
Root Directory:         /etc/selinux  
Loaded policy name:             targeted current  
mode:                   enforcing  
mode from Config file:          enforcing  
Policy MLS status:              enabled  
Policy deny_unknown status:     allowed  
Max Kernel policy version:      28

If you want to temporarily close, you can perform:

Setenforce 0

At this point the status is as follows:

[Root@rdo ~]# sestatus  
SELinux Status:                 enabled  
SELINUXFS mount:                /sys/fs/selinux SELinux  
Root Directory:         /etc/selinux  
Loaded policy name:             targeted current  
mode:                   permissive  
mode from Config file:          enforcing  
Policy MLS status:              enabled  
Policy deny_unknown status:     allowed  
Max Kernel policy version:      28    

If you want to shut down permanently, you can modify the profile/etc/selinux/config to Selinu to disabled.

[Root@rdo ~]# cat/etc/selinux/config # This file controls to the state of SELinux on the   
  
system.  
# selinux= can take one of these three values:  
#     Enforcing-selinux The security policy is enforced.  
#     Permissive-selinux Prints warnings instead of enforcing.  
#     Disabled-no SELinux policy is loaded.  
#SELINUX =enforcing  
selinux=disabled  
# 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  

Modifying the configuration file can also be done by executing the following command:

After the modification is complete, save the reboot, and reboot after the status as follows:

[Root@rdo ~]# sestatus  
SELinux Status:                 disabled