Common OpenStack Database Resource

https://blueprints.launchpad.net/puppet-openstacklib/+spec/commmon-openstack-database-resource

This spec proposes to introduce defined resource types in openstacklib to provide a common interface for setting up databases used by the major OpenStack services. The current modules for these services would use this interface rather than duplicating code across these modules.

Problem description

Nearly all of the Puppet modules for OpenStack services set up a database for themselves and most of them do this using nearly identical code. This causes a great deal of repetition across modules and will lead to inconsistencies.

Proposed change

Abstract the database functionality into defined resource types in the openstacklib module. This resource would implement the same functionality as the db::mysql class and db::mysql::host_access type already do in ceilometer, cinder, glance, heat, keystone, neutron, and nova and will make the ability to configure postgresql databases consistent. The new resource would use the newest mysql and postgresql modules.

Alternatives

The alternative to implementing this feature in openstacklib is to maintain the database setup functionality in each module separately. This would necessitate updating the postgresql classes in each module to work with the current version of the postgresql module as well as adding postgresql support to the heat module. If additional backends are desired they would have to be implemented in each module individually.

Data model impact

The ceilometer, cinder, glance, heat, keystone, neutron, and nova modules would be updated to depend on the openstacklib module and use the new database resources to configure their respective databases.

The mysql and postgresql subclasses of ceilometer, cinder, glance, heat, keystone, neutron, and nova modules would have their current code replaced with a call to the new defined resource type in openstacklib. No new classes would be needed for these modules, except for heat which would need to have a postgresql subclass added.

Module API impact

  • New defined resource types:

    openstacklib::db::mysql openstacklib::db::postgresql

    A later spec may introduce an openstacklib::db::mongodb resource.

  • Parameters for openstacklib::db::mysql:

    dbname : The name of the database;

    string; optional; default to the $title of the resource, i.e. ‘nova’

    user : The database user to create;

    string; optional; default to the $title of the resource, i.e. ‘nova’

    password_hash : Password hash to use for the database user for this service;

    string; required

    host : The IP address or hostname of the user in mysql_grant;

    string; optional; default to ‘127.0.0.1’

    charset : The charset to use for the database;

    string; optional; default to ‘utf8’

    collate : The collate to use for the database;

    string; optional; default to ‘utf8_unicode_ci’

    allowed_hosts : Additional hosts that are allowed to access this database;

    array or string; optional; default to undef

    privileges : Privileges given to the database user;

    string or array of strings; optional; default to ‘ALL’

  • Example use case for openstacklib::db::mysql:

    In ::nova::db::mysql:

    ::openstacklib::db::mysql { 'nova':
      password_hash => '2470C0C06DEE42FD1618BB99005ADCA2EC9D1E19',
      notify        => Exec['nova-db-sync'],
    }

    would create a mysql database called ‘nova’ with user 'nova@127.0.0.1‘. It would not allow other hosts access to the database. It will re-execute the ‘nova-db-sync’ exec when the database refreshes.

    Another example in ::keystone::db::mysql:

    ::openstacklib::db::mysql { 'keystone':
      password_hash  => '2470C0C06DEE42FD1618BB99005ADCA2EC9D1E19',
      host           => '1.2.3.4',
      allowed_hosts  => ['1.2.3.4', '5.6.7.8'],
      notify         => Exec['keystone-manage db_sync'],
      before         => Service['keystone'],
    }

    would create a mysql database called ‘keystone’ with user 'keystone@1.2.3.4‘ and grants to ‘keystone’ on hosts ‘1.2.3.4’ and ‘5.6.7.8’. The database will be set up before the keystone service is started and the ‘keystone-manage db_sync’ exec will be re-executed when it refreshes.

  • Parameters for openstacklib::db::postgresql:

    dbname : The name of the database;

    string; optional; default to the $title of the resource, i.e. ‘nova’

    user : The database user to create;

    string; optional; default to the $title of the resource, i.e. ‘nova’

    password_hash : Password hash to use for the database user for this service;

    string; required

    encoding : The charset or encoding to use for the database;

    string; optional; default to undef

  • Example use case for openstacklib::db::postgresql

    In ::nova::db::postgresql:

    ::openstacklib::db::postgresql { 'nova':
      password_hash => '2470C0C06DEE42FD1618BB99005ADCA2EC9D1E19',
      notify        => Exec['nova-db-sync'],
    }

    would create a postgresql database called ‘nova’ with user ‘nova’. It will re-execute the ‘nova-db-sync’ exec when the database refreshes.

    Another example in ::keystone::db::postgresql:

    ::openstacklib::db::postgresql { 'keystone':
      password_hash => '2470C0C06DEE42FD1618BB99005ADCA2EC9D1E19',
      notify        => Exec['nova-db-sync'],
      before        => Service['keystone'],
    }

    would create a postgresql database called ‘keystone’ with user ‘keystone’. The database will be set up before the keystone service is started and the ‘keystone-manage db_sync’ exec will be re-executed when it refreshes.

End user impact

None aside from the API.

Performance Impact

None

Deployer impact

The user needs to install the openstacklib module prior to using the ceilometer, cinder, glance, heat, keystone, neutron, or nova modules.

Developer impact

Changes to database setup will happen in the openstacklib module rather than in the individual OpenStack service modules.

Implementation

Assignee(s)

Primary assignee:
krinkle
Other contributors:
None

Work Items

  • Create new defined resource type in openstacklib.
  • Update ceilometer, cinder, glance, heat, keystone, neutron, and nova modules to depend on openstacklib and use the new resource.

Dependencies

None

Testing

Unit test fixtures of all puppet modules would need to be updated to install openstacklib. Existing tests in these modules would be replicated in openstacklib.

Documentation Impact

None

References

None