ovn central #27

Supports: bionic eoan focal groovy
Add to new model


Principal charm that deploys ovn-northd, the OVN central control daemon,
and ovsdb-server, the Open vSwitch Database (OVSDB).

The ovn-northd daemon is responsible for translating the high-level OVN
configuration into logical configuration consumable by daemons such as

The ovn-northd process talks to OVN Northbound- and Southbound- databases.

The ovsdb-server exposes endpoints over relations implemented by the ovsdb

The charm supports clustering of the OVSDB, you must have a odd number of
units for this to work. Note that write performance decreases as you
increase the number of units.

Running multiple ovn-northd daemons is supported and they will operate in
active/passive mode. The daemon uses a locking feature in the OVSDB to
automatically choose a single active instance.


The ovn-central charm provides the Northbound and Southbound OVSDB Databases
and the Open Virtual Network (OVN) central control daemon (ovn-northd). It is
used in conjunction with either the ovn-chassis
subordinate charm or the ovn-dedicated-chassis
principle charm.

Note: The OVN charms are supported starting with OpenStack Train.


The OpenStack Base bundle gives an example of how you
can deploy OpenStack and OVN with Vault to automate certificate
lifecycle management.

OVN makes use of Public Key Infrastructure (PKI) to authenticate and authorize
control plane communication. The charm therefore requires a Certificate
Authority to be present in the model as represented by the certificates

Refer to Open Virtual Network (OVN) in the OpenStack Charms
Deployment Guide
for details, including deployment steps.

Note: The ovn-central charm requires a minimum of three units to operate.

Network spaces

This charm supports the use of Juju network spaces.

By binding the ovsdb, ovsdb-cms and ovsdb-peer endpoints you can
influence which interface will be used for communication with consumers of the
Southbound DB, Cloud Management Systems (CMS) and cluster internal

juju deploy -n 3 --series focal \
    --bind "''=oam-space ovsdb=data-space" \

OVN RBAC and securing the OVN services

The charm enables RBAC in the OVN Southbound database by default.
The RBAC feature enforces authorization of individual chassis connecting to the
database, and also restricts database operations.

In the event of an individual chassis being compromised, RBAC will make it more
difficult to leverage database access for compromising other parts of the

Note: Due to how RBAC is implemented in ovsdb-server
the charm opens up a separate listener at port 16642 for connections from

The charm automatically enables the firewall and will allow traffic from its
cluster peers to port 6641, 6643, 6644 and 16642. CMS clients will be allowed
to talk to port 6641.

Anyone will be allowed to connect to port 6642.


Please report bugs on Launchpad.

For general questions please refer to the OpenStack Charm Guide.


(int) Maximum number of seconds of idle time on connection to client before sending an inactivity probe message. The Open vSwitch ovsdb-server default of 5 seconds may not be sufficient depending on type and load of the CMS you want to connect to OVN.
(string) Repository from which to install OVS+OVN May be one of the following: distro (default) ppa:somecustom/ppa (PPA name must include UCA OpenStack Release name) deb url sources entry|key id or a supported Ubuntu Cloud Archive pocket. Supported Ubuntu Cloud Archive pockets include: cloud:xenial-pike cloud:xenial-queens cloud:bionic-rocky Note that updating this setting to a source that is known to provide a later version of Ceph will trigger a software upgrade.