Setting path_mtu to reflect mtu for physical devices that handle traffic issued from br-tun makes ml2 plugin to calculate mtu for tenant networks properly, considering encapsulation headers. After that, calculated mtu values can be propagated into instances (currently, only DHCP approach is implemented; RA support for IPv6 subnets is under review). This change allows to run tunnelled tenant networks in multinode when underlying physical devices don't support jumbo frames. Note: changing the default value in neutron would not be backwards compatible, since it could slow down east-west tunnelled traffic in clouds that run on jumbo-aware networks. Change-Id: I8287677c7ad0f13fa9f5cb194f9372d04b78cb61 Related-Bug: #1527675
Neutron plugin specific files
Neutron plugins require plugin specific behavior.
The files under the directory, lib/neutron_plugins/, will be used
when their service is enabled.
Each plugin has lib/neutron_plugins/$Q_PLUGIN and define the following
functions.
Plugin specific configuration variables should be in this file.
- filename:
$Q_PLUGIN- The corresponding file name MUST be the same to plugin name
$Q_PLUGIN. Plugin specific configuration variables should be in this file.
- The corresponding file name MUST be the same to plugin name
functions
lib/neutron-legacy calls the following functions when the $Q_PLUGIN is enabled
neutron_plugin_create_nova_conf: optionally set options in nova_confneutron_plugin_install_agent_packages: install packages that is specific to plugin agent e.g. install_package bridge-utilsneutron_plugin_configure_common: set plugin-specific variables,Q_PLUGIN_CONF_PATH,Q_PLUGIN_CONF_FILENAME,Q_PLUGIN_CLASSneutron_plugin_configure_debug_commandneutron_plugin_configure_dhcp_agentneutron_plugin_configure_l3_agentneutron_plugin_configure_plugin_agentneutron_plugin_configure_serviceneutron_plugin_setup_interface_driverhas_neutron_plugin_security_group: return 0 if the plugin support neutron security group otherwise return 1neutron_plugin_check_adv_test_requirements: return 0 if requirements are satisfied otherwise return 1