# -- Background The Neutron Linux Bridge plugin is a plugin that allows you to manage connectivity between VMs on hosts that are capable of running a Linux Bridge. The Neutron Linux Bridge plugin consists of three components: 1) The plugin itself: The plugin uses a database backend (mysql for now) to store configuration and mappings that are used by the agent. The mysql server runs on a central server (often the same host as nova itself). 2) The neutron service host which will be running neutron. This can be run on the server running nova. 3) An agent which runs on the host and communicates with the host operating system. The agent gathers the configuration and mappings from the mysql database running on the neutron host. The sections below describe how to configure and run the neutron service with the Linux Bridge plugin. # -- Python library dependencies Make sure you have the following package(s) installed on neutron server host as well as any hosts which run the agent: bridge-utils python-mysqldb sqlite3 # -- Nova configuration (controller node) 1) Ensure that the neutron network manager is configured in the nova.conf on the node that will be running nova-network. network_manager=nova.network.neutron.manager.NeutronManager # -- Nova configuration (compute node(s)) 1) Configure the vif driver, and libvirt/vif type connection_type=libvirt libvirt_type=qemu libvirt_vif_type=ethernet libvirt_vif_driver=nova.virt.libvirt.vif.NeutronLinuxBridgeVIFDriver linuxnet_interface_driver=nova.network.linux_net.NeutronLinuxBridgeInterfaceDriver 2) If you want a DHCP server to be run for the VMs to acquire IPs, add the following flag to your nova.conf file: neutron_use_dhcp=true (Note: For more details on how to work with Neutron using Nova, i.e. how to create networks and such, please refer to the top level Neutron README which points to the relevant documentation.) # -- Neutron configuration Make the Linux Bridge plugin the current neutron plugin - edit neutron.conf and change the core_plugin core_plugin = neutron.plugins.linuxbridge.lb_neutron_plugin.LinuxBridgePluginV2 # -- Database config. (Note: The plugin ships with a default SQLite in-memory database configuration, and can be used to run tests without performing the suggested DB config below.) The Linux Bridge neutron plugin requires access to a mysql database in order to store configuration and mappings that will be used by the agent. Here is how to set up the database on the host that you will be running the neutron service on. MySQL should be installed on the host, and all plugins and clients must be configured with access to the database. To prep mysql, run: $ mysql -u root -p -e "create database neutron_linux_bridge" # log in to mysql service $ mysql -u root -p # The Linux Bridge Neutron agent running on each compute node must be able to # make a mysql connection back to the main database server. mysql> GRANT USAGE ON *.* to root@'yourremotehost' IDENTIFIED BY 'newpassword'; # force update of authorization changes mysql> FLUSH PRIVILEGES; (Note: If the remote connection fails to MySQL, you might need to add the IP address, and/or fully-qualified hostname, and/or unqualified hostname in the above GRANT sql command. Also, you might need to specify "ALL" instead of "USAGE".) # -- Plugin configuration - Edit the configuration file: etc/neutron/plugins/linuxbridge/linuxbridge_conf.ini Make sure it matches your mysql configuration. This file must be updated with the addresses and credentials to access the database. Note: debug and logging information should be updated in etc/neutron.conf Note: When running the tests, set the connection type to sqlite, and when actually running the server set it to mysql. At any given time, only one of these should be active in the conf file (you can comment out the other). - On the neutron server, network_vlan_ranges must be configured in linuxbridge_conf.ini to specify the names of the physical networks managed by the linuxbridge plugin, along with the ranges of VLAN IDs available on each physical network for allocation to virtual networks. An entry of the form "::" specifies a VLAN range on the named physical network. An entry of the form "" specifies a named network without making a range of VLANs available for allocation. Networks specified using either form are available for adminstrators to create provider flat networks and provider VLANs. Multiple VLAN ranges can be specified for the same physical network. The following example linuxbridge_conf.ini entry shows three physical networks that can be used to create provider networks, with ranges of VLANs available for allocation on two of them: [VLANS] network_vlan_ranges = physnet1:1000:2999,physnet1:3000:3999,physnet2,physnet3:1:4094 # -- Agent configuration - Edit the configuration file: etc/neutron/plugins/linuxbridge/linuxbridge_conf.ini - Copy neutron/plugins/linuxbridge/agent/linuxbridge_neutron_agent.py and etc/neutron/plugins/linuxbridge/linuxbridge_conf.ini to the compute node. - Copy the neutron.conf file to the compute node Note: debug and logging information should be updated in etc/neutron.conf - On each compute node, the network_interface_mappings must be configured in linuxbridge_conf.ini to map each physical network name to the physical interface connecting the node to that physical network. Entries are of the form ":". For example, one compute node may use the following physical_inteface_mappings entries: [LINUX_BRIDGE] physical_interface_mappings = physnet1:eth1,physnet2:eth2,physnet3:eth3 while another might use: [LINUX_BRIDGE] physical_interface_mappings = physnet1:em3,physnet2:em2,physnet3:em1 $ Run the following: python linuxbridge_neutron_agent.py --config-file neutron.conf --config-file linuxbridge_conf.ini Note that the the user running the agent must have sudo priviliges to run various networking commands. Also, the agent can be configured to use neutron-rootwrap, limiting what commands it can run via sudo. See http://wiki.openstack.org/Packager/Rootwrap for details on rootwrap. As an alternative to coping the agent python file, if neutron is installed on the compute node, the agent can be run as bin/neutron-linuxbridge-agent.