Fixes MariaDB to support Heat

When spawning Heat stacks, the DB reaches the max_connections
limit. This causes MariaDB to block all traffic by source IP,
essentially blocking all services. This patch introduces the
MARIADB_MAX_CONNECTIONS parameter to make the max_connections
configurable. The default of 151 max_connections is maintained.

Closes-Bug: #1465422

Change-Id: I869aa9f117c6fa959b1c6948dfc379f30a6bc1d7

docker/common/mariadb-app/config-mysql.sh

@@ -19,6 +19,7 @@ crudini --set $server_cnf mysqld default-storage-engine $DEFAULT_STORAGE_ENGINE
 crudini --set $server_cnf mysqld collation-server $COLLATION_SERVER
 crudini --set $server_cnf mysqld init-connect "'${INIT_CONNECT}'"
 crudini --set $server_cnf mysqld character-set-server $CHAR_SET_SERVER
+crudini --set $server_cnf mysqld max_connections "$MARIADB_MAX_CONNECTIONS"
 if [ "${INNODB_FILE_PER_TABLE}" == "true" ] || ["${INNODB_FILE_PER_TABLE}" == "True" ] ; then
     crudini --set $server_cnf mysqld innodb_file_per_table 1
 fi

docs/integration-guide.md

@@ -77,6 +77,7 @@ all containers.  This allows a simple method of ensuring every type of node
     KEYSTONE_PUBLIC_SERVICE_HOST=<IP> - The IP address where Keystone is running
     MARIADB_ROOT_PASSWORD=<mariadb root password> - defines the MariaDB root password
     MARIADB_SERVICE_HOST=<IP> - The IP Address where Mariadb is running
+    MARIADB_MAX_CONNECTIONS=<151> - The maximum number of connections to the MariaDB server
     NETWORK_MANAGER=<nova|neutron> - Use Nova or Neutron networking
     NOVA_API_SERVICE_HOST=<IP> - The IP Address where the Nova API Service is hosted
     METADATA_HOST=<IP> - The IP address of the Nova Metadata service

tools/genenv

@@ -31,6 +31,7 @@ INIT_HEAT_DB=true
 INIT_KEYSTONE_DB=true
 INIT_NOVA_DB=true
 MARIADB_ROOT_PASSWORD=kolla
+MARIADB_MAX_CONNECTIONS=151
 PASSWORD=12345
 
 
@@ -256,6 +257,7 @@ KEYSTONE_DB_PASSWORD=$KEYSTONE_DB_PASSWORD
 KEYSTONE_PUBLIC_SERVICE_HOST=$KEYSTONE_PUBLIC_SERVICE_HOST
 MARIADB_SERVICE_HOST=$HOST_IP
 MARIADB_ROOT_PASSWORD=$MARIADB_ROOT_PASSWORD
+MARIADB_MAX_CONNECTIONS=$MARIADB_MAX_CONNECTIONS
 NETWORK_MANAGER=$NETWORK_MANAGER
 NOVA_API_SERVICE_HOST=$NOVA_API_SERVICE_HOST
 NOVA_METADATA_API_SERVICE_HOST=$NOVA_METADATA_API_SERVICE_HOST