package mysql-server-5.7 5.7.20-0ubuntu0.16.04.1 failed to install/upgrade: subprocess installed post-installation script returned error exit status 1

[piyush]

unable to update any thing

ProblemType: Package
DistroRelease: Ubuntu 16.04
Package: mysql-server-5.7 5.7.20-0ubuntu0.16.04.1
ProcVersionSignature: Ubuntu 4.4.0-98.121-generic 4.4.90
Uname: Linux 4.4.0-98-generic x86_64
ApportVersion: 2.20.1-0ubuntu2.10
Architecture: amd64
Date: Tue Nov 7 12:41:28 2017
DpkgHistoryLog:
 Start-Date: 2017-11-07 12:41:24
 Commandline: /usr/bin/unattended-upgrade
 Upgrade: libssl1.0.0:amd64 (1.0.2g-1ubuntu4.8, 1.0.2g-1ubuntu4.9), libssl1.0.0:i386 (1.0.2g-1ubuntu4.8, 1.0.2g-1ubuntu4.9)
ErrorMessage: subprocess installed post-installation script returned error exit status 1
InstallationDate: Installed on 2016-12-26 (315 days ago)
InstallationMedia: Ubuntu 16.04.1 LTS "Xenial Xerus" - Release amd64 (20160719)
Logs.var.log.daemon.log:

MySQLConf.etc.mysql.conf.d.mysql.cnf: [mysql]
MySQLConf.etc.mysql.conf.d.mysqldump.cnf:
 [mysqldump]
 quick
 quote-names
 max_allowed_packet = 16M
MySQLConf.etc.mysql.mysql.conf.d.mysqld_safe_syslog.cnf:
 [mysqld_safe]
 syslog
MySQLVarLibDirListing: ['mysql', 'sys', 'mysql_upgrade_info', 'ibdata1', 'auto.cnf', 'ib_logfile0', 'performance_schema', 'ib_logfile1', 'debian-5.7.flag', 'ib_buffer_pool']
ProcCmdline: BOOT_IMAGE=/vmlinuz-4.4.0-98-generic root=UUID=3f3bf70d-b489-4ba2-9538-9c52439345f3 ro quiet splash vt.handoff=7
RelatedPackageVersions:
 dpkg 1.18.4ubuntu1.2
 apt 1.2.24
SourcePackage: mysql-5.7
Title: package mysql-server-5.7 5.7.20-0ubuntu0.16.04.1 failed to install/upgrade: subprocess installed post-installation script returned error exit status 1
UpgradeStatus: No upgrade log present (probably fresh install)
upstart.mysql.override: manual

[Joshua Powers (powersj)]

From log:

mysql_upgrade: Got error: 2002: Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (2) while connecting to the MySQL server

[Joshua Powers (powersj)]

Hey! Thanks for taking the time to file a bug. Based on the log message above it appears that this bug is actually a duplicate of LP: #1670629. I am going to mark this as a duplicate, but if you have additional information that says otherwise please feel free to put it here. Otherwise, checkout the other bug for information on a workaround.

Thanks again!