Problems installing mysql in ubuntu 18.04

Question

I have installed mysql since upgrading the operating system. But there seems to be a problem with the root password. I have tried to fix this in many ways on the web, so far it has not been successful.

systemctl status mysql.service give:

● mysql.service - MySQL Community Server
   Loaded: loaded (/lib/systemd/system/mysql.service; enabled; vendor preset: enabled)
   Active: failed (Result: exit-code) since Wed 2018-05-02 16:57:24 +07; 13s ago
  Process: 6172 ExecStartPre=/usr/share/mysql/mysql-systemd-start pre (code=exited, status=217/USER)
Thg 5 02 16:57:24 thiennguyen systemd[1]: mysql.service: Service hold-off time  over, scheduling restart.
Thg 5 02 16:57:24 thiennguyen systemd[1]: mysql.service: Scheduled restart job,  restart counter is at 5.
Thg 5 02 16:57:24 thiennguyen systemd[1]: Stopped MySQL Community Server.
Thg 5 02 16:57:24 thiennguyen systemd[1]: mysql.service: Start request repeated too quickly
Thg 5 02 16:57:24 thiennguyen systemd[1]: mysql.service: Failed with result 'exit-code'.
Thg 5 02 16:57:24 thiennguyen systemd[1]: Failed to start MySQL Community Server

journalctl -xe give: http://codepad.org/6EbGVu2Q

mysql_secure_installation give:

Securing the MySQL server deployment.
Enter password for user root: 
Error: Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (2)

mysql -u root -p give:

Enter password: 
ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (2)

Especially when I install, mysql does not require setting password for root and i have reinstalled many times. Maybe the problem is old, but I have found many ways on the network but can not solve, so look forward to the help.

Answer 1

The answer marked as correct is technically not right. Ubuntu 18.04 uses sockets for authorization and not passwords!!

(https://websiteforstudents.com/mariadb-installed-without-password-prompts-for-root-on-ubuntu-17-10-18-04-beta/)

For me logging in was as simple as:

sudo  mysql -u root      

I feel whoever is responsible for this "feature" really dropped the ball. There should have been a message stating that Ubuntu no longer used passwords when attempting to run mysql. this was a really drastic change in functionality.