Fix MariaDB 10.3 upgrade

There are a couple of issues with the mariadb image currently.

1. it doesn't include mysql_upgrade on CentOS/RHEL. It is necessary to
   run this after an upgrade of MariaDB. This is fixed by installing
   mariadb-server-utils.

2. it inherits the standard dumb-init entrypoint from the base image,
   which includes a --single-child argument. That causes signals to be
   forwarded only to the process executed by dumb-init, which in the
   case of kolla-ansible is mysqld_safe, however mysqld_safe ignores
   SIGTERM. After a timeout, Docker then forcibly kills the container.
   Executing dumb-init without --single-child ensures the TERM signal is
   sent to mysqld, allowing it to shutdown gracefully.

Change-Id: I1a450736721863b91be1ea3d3c8948990de9fdeb
Closes-Bug: #1820325

docker/mariadb/Dockerfile.j2

@@ -13,8 +13,9 @@ LABEL maintainer="{{ maintainer }}" name="{{ image_name }}" build-date="{{ build
         'galera',
         'hostname',
         'mariadb',
-        'mariadb-server-galera',
         'mariadb-backup',
+        'mariadb-server-galera',
+        'mariadb-server-utils',
         'pv',
         'rsync',
         'tar'
@@ -50,6 +51,17 @@ RUN chmod 755 /usr/local/bin/kolla_extend_start \
 {% if base_package_type == 'deb' %}
 RUN mkdir -p /var/run/mysqld && chown mysql /var/run/mysqld && chmod 755 /var/run/mysqld
 {% endif %}
+
+{% block mariadb_entrypoint %}
+# NOTE(mgoddard): Override the dumb-init arguments to avoid passing
+# --single-child. This does not play well with mysqld_safe, which ignores
+# SIGTERM, meaning Docker needs to forcibly kill the container to stop it.
+# Without --single-child, the TERM signal is sent to all subprocesses,
+# including mysqld.
+ENTRYPOINT ["dumb-init"]
+CMD ["kolla_start"]
+{% endblock %}
+
 {% block mariadb_footer %}{% endblock %}
 {% block footer %}{% endblock %}
 

docker/mariadb/extend_start.sh

@@ -38,6 +38,19 @@ if [[ "${!KOLLA_BOOTSTRAP[@]}" ]]; then
     exit 0
 fi
 
+# This catches all cases of the KOLLA_UPGRADE variable being set, including empty
+if [[ "${!KOLLA_UPGRADE[@]}" ]]; then
+    # The mysql_upgrade command treats any directories under /var/lib/mysql as
+    # databases. Somehow we can end up with a .pki directory, which causes the
+    # command to fail with this error:
+    # Incorrect database name '#mysql50#.pki' when selecting the database
+    # There doesn't seem to be anything in the directory, so remove it.
+    rm -rf /var/lib/mysql/.pki
+
+    mysql_upgrade --user=root --password="${DB_ROOT_PASSWORD}"
+    exit 0
+fi
+
 if [[ "${!BOOTSTRAP_ARGS[@]}" ]]; then
     ARGS="${BOOTSTRAP_ARGS}"
 fi