charm-guide/doc/source/getting-started/settings.rst

Collect local settings

This stage entails the collection of hardware and networking information from the local environment. In the tables below, the Placeholder column contains variables (e.g. EXT_GW) that will be referred to (e.g. $EXT_GW) on a later page where they are to be replaced by the environment's actual values (e.g. 10.246.112.1).

Assign a value to each variable now.

Hardware attribute	Tutorial example value	Placeholder	Comments
data port interface	bond1	OVN_DATA_PORT	the name of the network interface that the three OVN Chassis will bind to
storage devices	/dev/sda /dev/sdb /dev/sdc /dev/sdd	OSD_DEVICES	all possible block devices that can be used on the three cloud nodes -each cloud node will also act as a Ceph OSD node
constraints	cores=4,mem=16	CONSTRAINTS	optional - used to filter on MAAS nodes that align with the stated hardware requirements

Notes on the OVN Chassis network interface (OVN_DATA_PORT):

• An Open vSwitch (OVS) bridge is always needed (per node), and its name is determined by the ovn-chassis charm's ovn-bridge-mappings option in the bundle ('br-ex'). OVN_DATA_PORT denotes the name of the bridge's underlying interface (e.g. 'bond1' or 'enp1s0').
• When a second interface is not used on a node, an OVS bridge must be set up manually (see the MAAS page <cdg:ovs_bridge> in the Deploy Guide for help). In the MAAS web UI, this bridge must be associated with the subnet (EXT_SUBNET) and its IP address status should be set to either 'Auto assign' or 'Static assign'.
• When a second interface is used on a node, the charms will automatically create the OVS bridge. In the MAAS web UI, this interface must be associated with the subnet (EXT_SUBNET), but its IP address status should remain as 'Unconfigured'.
• It is convenient for the bridges' underlying interface names to be common. However, if this is not the case, individual hardware (MAC) addresses can be used instead. Make note of them.

External network attribute	Tutorial example value	Placeholder	Comments
subnet	10.246.112.0/21	EXT_SUBNET	a subnet within MAAS
gateway	10.246.112.1	EXT_GW	check MAAS settings
nameserver/DNS	10.246.112.3	EXT_DNS	check MAAS settings - if undefined, use the MAAS server address
floating IP range start	10.246.116.23	EXT_POOL_START	resides within the chosen subnet
floating IP range end	10.246.116.87	EXT_POOL_END	resides within the chosen subnet

The MAAS subnet (EXT_SUBNET) need not be dedicated to the cloud. The deployment simply makes address allocation requests to this address space for the cloud nodes (including LXD containers). The cloud will need a minimum of 22 addresses for its nodes plus any that may be used as floating IPs (for SSH connections).

Important

Since OpenStack manages floating IPs they must not be used by MAAS for any other purpose. To assure this, configure a "reserved IP range" in MAAS. See How to manage IP ranges in the MAAS documentation. In this context, the subnet (EXT_SUBNET) is considered "managed" in MAAS.

When you're done, move on to the overlay page.