package mysql-server-5.7 5.7.17-0ubuntu0.16.04.2 failed to install/upgrade: subprocess installed post-installation script returned error exit status 1

[Maikel]

error in Ubuntu release-upgrade to release 16.04.2

ProblemType: Package
DistroRelease: Ubuntu 16.04
Package: mysql-server-5.7 5.7.17-0ubuntu0.16.04.2
ProcVersionSignature: Ubuntu 3.16.0-30.40~14.04.1-generic 3.16.7-ckt3
Uname: Linux 3.16.0-30-generic x86_64
ApportVersion: 2.20.1-0ubuntu2.5
Architecture: amd64
Date: Mon Apr 17 16:10:26 2017
ErrorMessage: subprocess installed post-installation script returned error exit status 1
InstallationDate: Installed on 2015-03-18 (760 days ago)
InstallationMedia: Ubuntu-Server 14.04.2 LTS "Trusty Tahr" - Release amd64 (20150218.1)
Logs.var.log.daemon.log:

MySQLConf.etc.mysql.conf.d.mysql.cnf: [mysql]
MySQLConf.etc.mysql.conf.d.mysqld_safe_syslog.cnf:
 [mysqld_safe]
 syslog
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: ['zabbix', 'mysql', 'debian-5.5.flag', 'ib_logfile0', 'ib_logfile1', 'mysql_upgrade_info', 'auto.cnf', 'performance_schema', 'ibdata1', 'ib_buffer_pool', 'debian-5.7.flag']
ProcCmdline: BOOT_IMAGE=/vmlinuz-3.16.0-30-generic root=/dev/mapper/hostname--vg-root ro
RelatedPackageVersions:
 dpkg 1.18.4ubuntu1.1
 apt 1.2.19
SourcePackage: mysql-5.7
Title: package mysql-server-5.7 5.7.17-0ubuntu0.16.04.2 failed to install/upgrade: subprocess installed post-installation script returned error exit status 1
UpgradeStatus: Upgraded to xenial on 2017-04-17 (0 days ago)

[Maikel (maikelegberink)]

initial situation: Ubuntu 16.04 with 7 Package updates en 7 security updates waiting
After clean boot Ubuntu suggests to update to 16.04.2 with do-release-upgrade

from sudo-user I did
sudo update
sudo do-release-update

during release update Ubuntu asked me to use the new file for release-update
Old file: /etc/apt/apt.conf.d/50unattended-upgrades root.root 0644
New File: /etc/apt/apt.conf.d/50unattended-upgrades.ucftmp root.root 0644
I accepted the new file

after release-update Ubuntu finished with errors;

"Errors were encountered while processing:
 mysql-server-5.7
 mysql-server
Error in function:"

After clean reboot the Zabbix frontend (webGUI) didn't work anymore and gave the following error:
"Configuration error
--------------------
DB type "MYSQL" is not supported by current setup
Possible values."

Logging into mysql gave a lot of errors when reading config so I tried to stop mysql service, which took very long.
I then stopped the zabbix-server service, apache2 service and then again mysql service. After a few min it stopped. Then I started the previous mentioned services again but the same problem.
Then I logged into mysql and tried to repair database. After that I could succesfully read config.
Zabbix frontend still gave the same error.
After that my collegue did the following to correct the problem:
as sudo-user: sudo apt-get install php-mysql (which according to him installed php7 for mysql upgrade). After that he also fixed some more things (sorry don't know details)

Problem is solved now