Replace bionics mariadb-server 10.1 with 10.3 from upstream repo

The mariadb-server version shipping with Ubuntu 18.04 LTS (bionic) and
the version in the Ubuntu Cloud Archive (10.1) is too old to work with
the neutron database upgrade process in OpenStack Train. Therefore,
we install mariadb-server 10.3 from the upstream repo.

Change-Id: I7b5087e36914b5e612d01d671b85e62a39df1df7

labs/osbash/lib/functions.guest.sh

@@ -2,6 +2,7 @@
 
 # Sourcing this file calls functions fix_path_env and source_deploy.
 
+source "$CONFIG_DIR/credentials"
 source "$LIB_DIR/functions.sh"
 source "$LIB_DIR/functions-common-devstack"
 
@@ -300,8 +301,7 @@ $option = $value
 function mysql_exe {
     local cmd="$1"
     echo "mysql cmd: $cmd."
-    # XXX install-guide uses password, but distro install uses socket auth
-    sudo mysql -u "root" -e "$cmd"
+    sudo mysql -u "root" -p"$DATABASE_PASSWORD" -e "$cmd"
 }
 
 function setup_database {

labs/osbash/scripts/ubuntu/apt_init.sh

@@ -88,3 +88,29 @@ fi
 # Disable automatic updates (they compete with our scripts for the dpkg lock)
 sudo systemctl disable apt-daily.service
 sudo systemctl disable apt-daily.timer
+
+# ---------------------------------------------------------------------------
+# Not in install-guide:
+# Install mariadb-server from upstream repo (mariadb 10.1 shipping with
+# bionic breaks the neutron database upgrade process in OpenStack Train)
+# ---------------------------------------------------------------------------
+
+# Add mariadb repo
+cat << EOF | sudo tee /etc/apt/sources.list.d/mariadb.list
+# bionic mariadb 10.1 breaks neutron DB upgrade process in OpenStack Train
+deb http://downloads.mariadb.com/MariaDB/mariadb-10.3/repo/ubuntu bionic main
+EOF
+
+# Import key required for mariadb
+sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys F1656F24C74CD1D8
+
+# Update apt database for mariadb repo
+sudo apt update \
+    -o Dir::Etc::sourcelist="sources.list.d/mariadb.list" \
+    -o Dir::Etc::sourceparts="-" -o APT::Get::List-Cleanup="0"
+
+# Pre-configure database root password in /var/cache/debconf/passwords.dat
+# (the upstream mariadb-server has socket_auth disabled)
+source "$CONFIG_DIR/credentials"
+echo "mysql-server mysql-server/root_password password $DATABASE_PASSWORD" | sudo debconf-set-selections
+echo "mysql-server mysql-server/root_password_again password $DATABASE_PASSWORD" | sudo debconf-set-selections

labs/osbash/scripts/ubuntu/apt_install_mysql.sh

@@ -34,8 +34,8 @@ echo "Installing MySQL (MariaDB)."
 sudo apt install -y mariadb-server python-mysqldb
 
 # Not in the install-guide
-echo "Sanity check: distro default is socket auth."
-sudo mysql -u root -e quit
+echo "Sanity check: check if password login works for root."
+sudo mysql -u root -p"$DATABASE_PASSWORD" -e quit
 
 # Not in install-guide
 # To drop socket auth for root user and use root password: