Comment 2 for bug 1740835

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

While it looks like the post-install failed, but looks like the server
is up and waiting:

2018-01-02T09:23:07.999499Z 0 [Note] /usr/sbin/mysqld: ready for connections.
Version: '5.7.20-0ubuntu0.16.04.1' socket: '/var/run/mysqld/mysqld.sock' port: 3306 (Ubuntu)
2018-01-02T09:23:07.999518Z 0 [Note] Executing 'SELECT * FROM INFORMATION_SCHEMA.TABLES;' to get a list of tables using the deprecated partition engine. You may use the startup option '--disable-partition-engine-check' to skip this check.
2018-01-02T09:23:07.999525Z 0 [Note] Beginning of list of non-natively partitioned tables
2018-01-02T09:23:08.490012Z 0 [Note] End of list of non-natively partitioned tables
2018-01-02T09:23:08.535226Z 3 [Note] Access denied for user 'root'@'localhost' (using password: NO)

Are you sure you are using the correct password and username that
you setup during the install? Can you provide the output you are seeing
when you try to connect and the output of /var/log/mysql/error.log after
attempting?

Since there is not enough information in your report to begin triage or to
differentiate between a local configuration problem and a bug in Ubuntu, I
am marking this bug as "Incomplete". We would be grateful if you would:
provide a more complete description of the problem, 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