Configure the database with dbconfig-common

Configure the database with dbconfig-common

Many of the OpenStack services need to be configured to access a database. These are configured through a DSN (Database Source Name) directive as follows:

[database]
connection = mysql+pymysql://keystone:0dec658e3f14a7d@localhost/keystonedb

This connection directive will be handled by the dbconfig-common package, which provides a standard Debian interface. It enables you to configure Debian database parameters. It includes localized prompts for many languages and it supports the following database backends: SQLite, MySQL, and PostgreSQL.

By default, the dbconfig-common package configures the OpenStack services to use SQLite. So if you use debconf in non-interactive mode and without pre-seeding, the OpenStack services that you install will use SQLite.

By default, dbconfig-common does not provide access to database servers over a network. If you want the dbconfig-common package to prompt for remote database servers that are accessed over a network and not through a UNIX socket file, reconfigure it, as follows:

# apt-get install dbconfig-common && dpkg-reconfigure dbconfig-common

These screens appear when you re-configure the dbconfig-common package:

../_images/dbconfig-common_keep_admin_pass.png

../_images/dbconfig-common_used_for_remote_db.png

Unlike other debconf prompts, you cannot pre-seed the responses for the dbconfig-common prompts by using debconf-set-selections. Instead, you must create a file in /etc/dbconfig-common. For example, you might create a keystone configuration file for dbconfig-common that is located in /etc/dbconfig-common/keystone.conf, as follows:

dbc_install='true'
dbc_upgrade='true'
dbc_remove=''
dbc_dbtype='mysql'
dbc_dbuser='keystone'
dbc_dbpass='PASSWORD'
dbc_dbserver=''
dbc_dbport=''
dbc_dbname='keystonedb'
dbc_dbadmin='root'
dbc_basepath=''
dbc_ssl=''
dbc_authmethod_admin=''
dbc_authmethod_user=''

After you create this file, run this command:

# apt-get install keystone

The Identity service is installed with MySQL as the database back end, keystonedb as database name, and the localhost socket file. The corresponding DSN (Database Source Name) will then be:

[database]
connection = mysql+pymysql://keystone:PASSWORD@localhost/keystonedb

The dbconfig-common package will configure MySQL for these access rights, and create the database for you. Since OpenStack 2014.1.1, all OpenStack packages in Debian are performing the following MySQL query after database creation (if you decide to use MySQL as a back-end):

ALTER DATABASE keystone CHARACTER SET utf8 COLLATE utf8_unicode_ci

So, if using Debian, you wont need to care about database creation, access rights and character sets. All that is handled for you by the packages.

As an example, here are screenshots from the cinder-common package:

../_images/dbconfig-common_1_configure-with-dbconfig-yes-no.png

../_images/dbconfig-common_2_db-types.png

../_images/dbconfig-common_3_connection_method.png

../_images/dbconfig-common_4_mysql_root_password.png

../_images/dbconfig-common_5_mysql_app_password.png

../_images/dbconfig-common_6_mysql_app_password_confirm.png

By default in Debian, you can access the MySQL server from either localhost through the socket file or 127.0.0.1. To access it over the network, you must edit the /etc/mysql/my.cnf file, and the mysql.user table. To do so, Debian provides a helper script in the openstack-deploy package. To use it, install the package:

# apt-get install openstack-deploy

and run the helper script:

# /usr/share/openstack-deploy/mysql-remote-root

Alternatively, if you do not want to install this package, run this script to enable remote root access:

#!/bin/sh

set -e

SQL="mysql --defaults-file=/etc/mysql/debian.cnf -Dmysql -e"

ROOT_PASS=`${SQL} "SELECT Password FROM user WHERE User='root' LIMIT 1;" \
  | tail -n 1`
${SQL} "REPLACE INTO user SET host='%', user='root',\
  password='${ROOT_PASS}', Select_priv='Y', Insert_priv='Y',\
  Update_priv='Y', Delete_priv='Y', Create_priv='Y', Drop_priv='Y',\
  Reload_priv='Y', Shutdown_priv='Y', Process_priv='Y',  File_priv='Y',\
  Grant_priv='Y', References_priv='Y', Index_priv='Y', Alter_priv='Y',\
  Super_priv='Y', Show_db_priv='Y', Create_tmp_table_priv='Y',\
  Lock_tables_priv='Y', Execute_priv='Y', Repl_slave_priv='Y',\
  Repl_client_priv='Y', Create_view_priv='Y', Show_view_priv='Y',\
  Create_routine_priv='Y', Alter_routine_priv='Y', Create_user_priv='Y',\
  Event_priv='Y', Trigger_priv='Y' "
${SQL} "FLUSH PRIVILEGES"
sed -i 's|^bind-address[ \t]*=.*|bind-address = 0.0.0.0|' /etc/mysql/my.cnf
/etc/init.d/mysql restart

You must enable remote access before you install OpenStack services on multiple nodes.

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