Fix MariaDB 10.3 installation under Ubuntu 20.04. (brianmario#1184)

Author: vakuum

.github/workflows/build.yml

@@ -31,7 +31,7 @@ jobs:
           - {os: ubuntu-16.04, ruby: 2.4, db: mariadb10.0, allow-failure: true}
           # Comment out due to ci/setup.sh stucking.
           # - {os: ubuntu-18.04, ruby: 2.4, db: mariadb10.1}
-          # `service mysql restart` fails.
+          # Allow failure due to the issue #965, #1165.
           - {os: ubuntu-20.04, ruby: 2.4, db: mariadb10.3, allow-failure: true}
           - {os: ubuntu-18.04, ruby: 2.4, db: mysql57}
           # Allow failure due to the issue #1165.

ci/setup.sh

@@ -72,8 +72,12 @@ fi
 
 # Install MariaDB 10.3 if DB=mariadb10.3
 if [[ -n ${GITHUB_ACTIONS-} && -n ${DB-} && x$DB =~ ^xmariadb10.3 ]]; then
+  sudo ln -s /etc/apparmor.d/usr.sbin.mysqld /etc/apparmor.d/disable/
+  sudo apparmor_parser -R /etc/apparmor.d/usr.sbin.mysqld
+  sudo apt-get purge -y 'mysql-common*' 'mysql-client*' 'mysql-server*'
+  sudo rm -rf /etc/mysql /var/lib/mysql
   sudo apt-get install -y -o Dpkg::Options::='--force-confnew' mariadb-server mariadb-server-10.3 libmariadb-dev
-  CHANGED_PASSWORD=true
+  CHANGED_PASSWORD_BY_RECREATE=true
 fi
 
 # Install MySQL/MariaDB if OS=darwin