Installing the ML2 plugin

RHEL-based distributions, such as CentOS, require the installation of the openstack-neutron-ml2 package on all nodes as follows:

# yum install openstack-neutron-ml2

Creating a database for ML2

The ML2 plugin attempts to use a common database and schema that can be shared amongst multiple layer 2 agents. On the controller node, create a new database specifically for use with the ML2 plugin using the MySQL client:

# mysql -u root -p

Use the password set earlier in the OpenStack installation. In this guide, the password was set to openstack.

At the mysql> prompt, execute the following commands to create a database named neutron_ml2 and to grant permissions to the existing neutron user:

CREATE DATABASE neutron_ml2;
GRANT ALL PRIVILEGES ON neutron_ml2.* TO 'neutron'@'localhost' 
IDENTIFIED BY 'neutron';
GRANT ALL PRIVILEGES ON neutron_ml2.* TO 'neutron'@'%'; 
QUIT;

Use crudini to overwrite the existing database connection string in the Neutron configuration file with the new string on all hosts as follows:

# crudini --set /etc/neutron/neutron.conf database connection mysql://neutron:neutron@controller/neutron_ml2

Configuring Neutron to use ML2

Before the ML2 plugin can be used, changes, which include specifying the core plugin and database options, must be made to the Neutron configuration on all hosts.

The core_plugin configuration must be set to use the ML2 plugin. Use the following crudini command to make this change on all hosts:

# crudini --set /etc/neutron/neutron.conf DEFAULT core_plugin neutron.plugins.ml2.plugin.Ml2Plugin

In addition to configuration file changes, a symbolic link named plugin.ini must be created in the /etc/neutron/ directory that points to the appropriate plugin configuration file before neutron-server will start. For ML2, the link can be created with the following command:

# ln -s /etc/neutron/plugins/ml2/ml2_conf.ini /etc/neutron/plugin.ini

If you previously used the LinuxBridge or Open vSwitch plugin and are switching to ML2, be sure to remove the corresponding symbolic link prior to creating a new one for ML2.

The Neutron database must be stamped as the havana release before neutron-server starts. Use the neutron-db-manage command to accomplish this task only on the controller:

# neutron-db-manage --config-file /etc/neutron/plugin.ini --config-file /etc/neutron/neutron.conf stamp havana

Configuring service plugins

When the ML2 plugin is used, the L3 router plugin must be defined as a service plugin in the neutron.conf configuration file in addition to the FWaaS and LBaaS service plugins. The following are the service plugins for each of the services:

• Routing: neutron.services.l3_router.l3_router_plugin.L3RouterPlugin

• Load balancing: neutron.services.loadbalancer.plugin.LoadBalancerPlugin

• Firewalling: neutron.services.firewall.fwaas_plugin.FirewallPlugin

To add support for the aforementioned services, add them to the service_plugins configuration option in /etc/neutron/neutron.conf using a text editor as follows:

service_plugins= neutron.services.l3_router.l3_router_plugin.L3RouterPlugin, neutron.services.loadbalancer.plugin.LoadBalancerPlugin, neutron.services.firewall.fwaas_plugin.FirewallPlugin