我不断得到错误：
错误2002（hy000）：无法通过套接字'/var/run/mysqld/mysqld.sock'（2）连接到本地mysql服务器
尝试通过终端连接mysql时。
我已经完成了两个教程：
官方说法：https://help.ubuntu.com/community/mysqlpasswordreset
还有一个不太正式的：https://coderwall.com/p/j9btlg/reset-the-mysql-5-7-root-password-in-ubuntu-16-04-lts
创建文件 /var/run/mysqld/mysqld.sock 在授予它权限后实际工作
chown -R mysql /var/run/mysqld chown -R mysql /var/run/mysqld/mysqld.sock 然后我可以在终端上登录mysql，修改我的主用户和根用户的密码。
运行后 sudo /etc/init.d/mysql start 或者 sudo /etc/init.d/mysql restart 我再次-无法连接到mysql使用我的用户名和密码。

service mysql status
● mysql.service - MySQL Community Server
   Loaded: loaded (/lib/systemd/system/mysql.service; enabled; vendor preset: enabled)
   Active: active (running) since Mon 2018-05-07 12:00:51 IDT; 43s ago
  Process: 11057 ExecStartPost=/usr/share/mysql/mysql-systemd-start post (code=exited, status=0/SUCCESS)
  Process: 11042 ExecStartPre=/usr/share/mysql/mysql-systemd-start pre (code=exited, status=0/SUCCESS)
 Main PID: 11056 (mysqld)
    Tasks: 13 (limit: 4915)
   Memory: 103.3M
      CPU: 464ms
   CGroup: /system.slice/mysql.service
           └─11056 /usr/sbin/mysqld

May 07 12:00:20 asd systemd[1]: Starting MySQL Community Server...
May 07 12:00:51 asd systemd[1]: Started MySQL Community Server.

以下帖子：error 2002（hy000）：无法通过socket'/var/run/mysqld/mysql.sock'连接到本地mysql服务器（2）
重新启动mysql在运行的时候并没有像帖子中提到的那样起作用 sudo /etc/init.d/mysql start 再次显示结果：

sudo /etc/init.d/mysql start
shell-init: error retrieving current directory: getcwd: cannot access parent directories: No such file or directory
job-working-directory: error retrieving current directory: getcwd: cannot access parent directories: No such file or directory
job-working-directory: error retrieving current directory: getcwd: cannot access parent directories: No such file or directory
sh: 0: getcwd() failed: No such file or directory
job-working-directory: error retrieving current directory: getcwd: cannot access parent directories: No such file or directory
job-working-directory: error retrieving current directory: getcwd: cannot access parent directories: No such file or directory
job-working-directory: error retrieving current directory: getcwd: cannot access parent directories: No such file or directory
job-working-directory: error retrieving current directory: getcwd: cannot access parent directories: No such file or directory
job-working-directory: error retrieving current directory: getcwd: cannot access parent directories: No such file or directory
job-working-directory: error retrieving current directory: getcwd: cannot access parent directories: No such file or directory
[....] Starting mysql (via systemctl): mysql.servicejob-working-directory: error retrieving current directory: getcwd: cannot access parent directories: No such file or directory
job-working-directory: error retrieving current directory: getcwd: cannot access parent directories: No such file or directory
job-working-directory: error retrieving current directory: getcwd: cannot access parent directories: No such file or directory
job-working-directory: error retrieving current directory: getcwd: cannot access parent directories: No such file or directory
job-working-directory: error retrieving current directory: getcwd: cannot access parent directories: No such file or directory
job-working-directory: error retrieving current directory: getcwd: cannot access parent directories: No such file or directory
job-working-directory: error retrieving current directory: getcwd: cannot access parent directories: No such file or directory
job-working-directory: error retrieving current directory: getcwd: cannot access parent directories: No such file or directory
job-working-directory: error retrieving current directory: getcwd: cannot access parent directories: No such file or directory
job-working-directory: error retrieving current directory: getcwd: cannot access parent directories: No such file or directory
job-working-directory: error retrieving current directory: getcwd: cannot access parent directories: No such file or directory
[ ok job-working-directory: error retrieving current directory: getcwd: cannot access parent directories: No such file or directory
job-working-directory: error retrieving current directory: getcwd: cannot access parent directories: No such file or directory
job-working-directory: error retrieving current directory: getcwd: cannot access parent directories: No such file or directory
job-working-directory: error retrieving current directory: getcwd: cannot access parent directories: No such file or directory
job-working-directory: error retrieving current directory: getcwd: cannot access parent directories: No such file or directory
job-working-directory: error retrieving current directory: getcwd: cannot access parent directories: No such file or directory
job-working-directory: error retrieving current directory: getcwd: cannot access parent directories: No such file or directory
.
sudo service mysql start
sh: 0: getcwd() failed: No such file or directory

完全重新安装mysql是不可接受的。
一位评论人士说：
客户端设置应与服务器设置一致。

[client]
port        = 3306
socket      = /var/run/mysqld/mysqld.sock

[mysqld]
user        = mysql
pid-file    = /var/run/mysqld/mysqld.pid
socket      = /var/run/mysqld/mysqld.sock
port        = 3306

这很奇怪因为在我的目录里 /var/run/mysqld/ 这个 mysqld.sock 文件以某种方式被删除，并且在我的 /etc/mysql/my.cnf 文件：

# 

# The MySQL database server configuration file.

# 

# You can copy this to one of:

# - "/etc/mysql/my.cnf" to set global options,

# - "~/.my.cnf" to set user-specific options.

# 

# One can use all long options that the program supports.

# Run program with --help to get a list of available options and with

# --print-defaults to see which it would actually understand and use.

# 

# For explanations see

# http://dev.mysql.com/doc/mysql/en/server-system-variables.html

# 

# * IMPORTANT: Additional settings that can override those from this file!

# The files must end with '.cnf', otherwise they'll be ignored.

# 

!includedir /etc/mysql/conf.d/
!includedir /etc/mysql/mysql.conf.d/

# bind-address = 127.0.0.1

如何正确稳定mysql登录？为什么会这样？
跑步：

Distributor ID: Ubuntu
Description:    Ubuntu 17.10
Release:    17.10
Codename:   artful