package mysql-server-5.7 5.7.21-1ubuntu1 failed to install/upgrade: installed mysql-server-5.7 package post-installation script subprocess returned error exit status 1

[Gulshan Kumar]

Sub-process /usr/bin/dpkg returned an error code (1)

ProblemType: Package
DistroRelease: Ubuntu 18.04
Package: mysql-server-5.7 5.7.21-1ubuntu1
ProcVersionSignature: Ubuntu 4.15.0-20.21-generic 4.15.17
Uname: Linux 4.15.0-20-generic x86_64
ApportVersion: 2.20.9-0ubuntu7
AptOrdering:
 apache2:amd64: Install
 apache2-bin:amd64: Install
 apache2-utils:amd64: Install
 apache2-data:amd64: Install
 NULL: ConfigurePending
Architecture: amd64
CasperVersion: 1.394
Date: Tue May 22 08:58:46 2018
ErrorMessage: installed mysql-server-5.7 package post-installation script subprocess returned error exit status 1
LiveMediaBuild: Ubuntu 18.04 LTS "Bionic Beaver" - Release amd64 (20180426)
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: ['ib_buffer_pool', 'debian-5.7.flag', 'sys', 'performance_schema', 'mysql', 'auto.cnf', 'ib_logfile0', 'ib_logfile1', 'ibdata1']
ProcCmdline: BOOT_IMAGE=/casper/vmlinuz file=/cdrom/preseed/hostname.seed boot=casper quiet splash ---
Python3Details: /usr/bin/python3.6, Python 3.6.5, python3-minimal, 3.6.5-3
PythonDetails: /usr/bin/python2.7, Python 2.7.15rc1, python-minimal, 2.7.15~rc1-1
RelatedPackageVersions:
 dpkg 1.19.0.5ubuntu2
 apt 1.6.1
SourcePackage: mysql-5.7
Title: package mysql-server-5.7 5.7.21-1ubuntu1 failed to install/upgrade: installed mysql-server-5.7 package post-installation script subprocess returned error exit status 1
UpgradeStatus: No upgrade log present (probably fresh install)

[Joshua Powers (powersj)]

From terminal log:

ERROR: Unable to start MySQL server:
mysqld: Can't read dir of '/etc/mysql/conf.d/' (Errcode: 13 - Permission denied)
mysqld: [ERROR] Fatal error in defaults handling. Program aborted!

[Joshua Powers (powersj)]

Thank you for taking the time to file a bug report.

Looks like something is wrong with permissions.

Since it seems likely to me that this is a local configuration problem,
rather than a bug in Ubuntu, I am marking this bug as 'Incomplete'.

However, if you believe that this is really a bug in Ubuntu, then we would
be grateful if you would provide a more complete description of the problem
with steps to reproduce, explain why you believe this is a bug in Ubuntu
rather than a problem specific to your system, and then change the bug
status back to "New".

For local configuration issues, you can find assistance here:
http://www.ubuntu.com/support/community