$ mysqldump --all-databases > all_databases.sql
$ wget https://dev.mysql.com/get/mysql-apt-config_0.8.10-1_all.deb
$ sudo dpkg -i mysql-apt-config_0.8.1-1_all.deb
Choose version 5.7 -> OK
$ sudo apt-get update
$ sudo apt-get install mysql-server
$ sudo service mysql restart