Ubuntu Manpage: ovn-nb - OVN_Northbound database schema

Provided by: ovn-central_2.5.9-0ubuntu0.16.04.3_amd64

NAME

       ovn-nb - OVN_Northbound database schema

       This  database is the interface between OVN and the cloud management system (CMS), such as
       OpenStack, running above it.  The CMS produces almost all of the contents of the database.
       The  ovn-northd  program monitors the database contents, transforms it, and stores it into
       the OVN_Southbound database.

       We generally speak of ``the’’ CMS, but one can imagine scenarios in which  multiple  CMSes
       manage different parts of an OVN deployment.

   External IDs
       Each  of  the tables in this database contains a special column, named external_ids.  This
       column has the same form and purpose each place it appears.

              external_ids: map of string-string pairs
                     Key-value pairs for use by the CMS.  The CMS might use  certain  pairs,  for
                     example,  to  identify  entities in its own configuration that correspond to
                     those in this database.

TABLE SUMMARY

       The following list summarizes the purpose of each of  the  tables  in  the  OVN_Northbound
       database.  Each table is described in more detail on a later page.

       Table     Purpose
       Logical_Switch
                 L2 logical switch
       Logical_Port
                 L2 logical switch port
       ACL       Access Control List (ACL) rule
       Logical_Router
                 L3 logical router
       Logical_Router_Port
                 L3 logical router port

Logical_Switch TABLE

       Each row represents one L2 logical switch.

   Summary:
       name                          string
       ports                         set of Logical_Ports
       acls                          set of ACLs
       Common Columns:
         external_ids                map of string-string pairs

   Details:
       name: string
              A  name  for the logical switch.  This name has no special meaning or purpose other
              than to provide convenience for human interaction with the ovn-nb database.   There
              is  no  requirement for the name to be unique.  The logical switch’s UUID should be
              used as the unique identifier.

       ports: set of Logical_Ports
              The logical ports connected to the logical switch.

              It is an error for multiple logical switches to include the same logical port.

       acls: set of ACLs
              Access control rules that apply to packets within the logical switch.

     Common Columns:

       external_ids: map of string-string pairs
              See External IDs at the beginning of this document.

Logical_Port TABLE

A port within an L2 logical switch.

Summary:
Core Features:
name string (must be unique within table)
type string
Options:
options map of string-string pairs
Options for router ports:
options : router-port optional string
Options for localnet ports:
options : network_name optional string
Options for vtep ports:
options : vtep-physical-switch
optional string
options : vtep-logical-switch
optional string
Containers:
parent_name optional string
tag optional integer, in range 1 to 4,095
Port State:
up optional boolean
enabled optional boolean
Addressing:
addresses set of strings
port_security set of strings
Common Columns:
external_ids map of string-string pairs

Details:
Core Features:

name: string (must be unique within table)
The logical port name.

For entities (VMs or containers) that are spawned in the hypervisor, the name used
here must match those used in the external_ids:iface-id in the Open_vSwitch
database’s Interface table, because hypervisors use external_ids:iface-id as a
lookup key to identify the network interface of that entity.

For containers that share a VIF within a VM, the name can be any unique identifier.
See Containers, below, for more information.

type: string
Specify a type for this logical port. Logical ports can be used to model other
types of connectivity into an OVN logical switch. The following types are defined:

(empty string)
A VM (or VIF) interface.

router A connection to a logical router.

localnet
A connection to a locally accessible network from each ovn-controller
instance. A logical switch can only have a single localnet port attached
and at most one regular logical port. This is used to model direct
connectivity to an existing network.

vtep A port to a logical switch on a VTEP gateway.

Options:

options: map of string-string pairs
This column provides key/value settings specific to the logical port type. The
type-specific options are described individually below.

Options for router ports:
These options apply when type is router.

If a given logical switch has multiple router ports, the Logical_Router_Port rows that
they reference must be all on the same Logical_Router (for different subnets).

options : router-port: optional string
Required. The name of the Logical_Router_Port to which this logical switch port is
connected.

Options for localnet ports:
These options apply when type is localnet.

options : network_name: optional string
Required. The name of the network to which the localnet port is connected. Each
hypervisor, via ovn-controller, uses its local configuration to determine exactly
how to connect to this locally accessible network.

Options for vtep ports:
These options apply when type is vtep.

options : vtep-physical-switch: optional string
Required. The name of the VTEP gateway.

options : vtep-logical-switch: optional string
Required. A logical switch name connected by the VTEP gateway.

Containers:
When a large number of containers are nested within a VM, it may be too expensive to
dedicate a VIF to each container. OVN can use VLAN tags to support such cases. Each
container is assigned a VLAN ID and each packet that passes between the hypervisor and the
VM is tagged with the appropriate ID for the container. Such VLAN IDs never appear on a
physical wire, even inside a tunnel, so they need not be unique except relative to a
single VM on a hypervisor.

These columns are used for VIFs that represent nested containers using shared VIFs. For
VMs and for containers that have dedicated VIFs, they are empty.

parent_name: optional string
The VM interface through which the nested container sends its network traffic.
This must match the name column for some other Logical_Port.

tag: optional integer, in range 1 to 4,095
The VLAN tag in the network traffic associated with a container’s network
interface.

When type is set to localnet, this can be set to indicate that the port represents
a connection to a specific VLAN on a locally accessible network. The VLAN ID is
used to match incoming traffic and is also added to outgoing traffic.

Port State:

up: optional boolean
This column is populated by ovn-northd, rather than by the CMS plugin as is most of
this database. When a logical port is bound to a physical location in the OVN
Southbound database Binding table, ovn-northd sets this column to true; otherwise,
or if the port becomes unbound later, it sets it to false. This allows the CMS to
wait for a VM’s (or container’s) networking to become active before it allows the
VM (or container) to start.

enabled: optional boolean
This column is used to administratively set port state. If this column is empty or
is set to true, the port is enabled. If this column is set to false, the port is
disabled. A disabled port has all ingress and egress traffic dropped.

Addressing:

addresses: set of strings
Addresses owned by the logical port.

Each element in the set must take one of the following forms:

xx:xx:xx:xx:xx:xx
An Ethernet address owned by the logical port. Like a physical Ethernet
NIC, a logical port ordinarily has a single fixed Ethernet address.

When a OVN logical switch processes a unicast Ethernet frame whose
destination MAC address is in a logical port’s addresses column, it delivers
it only to that port, as if a MAC learning process had learned that MAC
address on the port.

xx:xx:xx:xx:xx:xx a.b.c.d
This form has all the effects of the previous form. It also indicates that
the logical port owns the given IPv4 address.

The OVN logical switch uses this information to synthesize responses to ARP
requests without traversing the physical network. The OVN logical router
connected to the logical switch, if any, uses this information to avoid
issuing ARP requests for logical switch ports.

Note that the order here is important. The Ethernet address must be listed
before the IP address.

unknown
This indicates that the logical port has an unknown set of Ethernet
addresses. When an OVN logical switch processes a unicast Ethernet frame
whose destination MAC address is not in any logical port’s addresses column,
it delivers it to the port (or ports) whose addresses columns include
unknown.

port_security: set of strings
A set of L2 (Ethernet) addresses from which the logical port is allowed to send
packets and to which it is allowed to receive packets. If this column is empty,
all addresses are permitted. Logical ports are always allowed to receive packets
addressed to multicast and broadcast addresses.

Each member of the set is an Ethernet address in the form xx:xx:xx:xx:xx:xx.

This specification will be extended to support L3 port security.

Common Columns:

external_ids: map of string-string pairs
See External IDs at the beginning of this document.

ACL TABLE

Each row in this table represents one ACL rule for a logical switch that points to it
through its acls column. The action column for the highest-priority matching row in this
table determines a packet’s treatment. If no row matches, packets are allowed by default.
(Default-deny treatment is possible: add a rule with priority 0, 0 as match, and deny as
action.)

Summary:
priority integer, in range 0 to 32,767
direction string, either to-lport or from-lport
match string
action string, one of allow-related, drop, allow, or reject
log boolean
Common Columns:
external_ids map of string-string pairs

Details:
priority: integer, in range 0 to 32,767
The ACL rule’s priority. Rules with numerically higher priority take precedence
over those with lower. If two ACL rules with the same priority both match, then
the one actually applied to a packet is undefined.

Return traffic from an allow-related flow is always allowed and cannot be changed
through an ACL.

direction: string, either to-lport or from-lport
Direction of the traffic to which this rule should apply:

• from-lport: Used to implement filters on traffic arriving from a logical
port. These rules are applied to the logical switch’s ingress pipeline.

• to-lport: Used to implement filters on traffic forwarded to a logical port.
These rules are applied to the logical switch’s egress pipeline.

match: string
The packets that the ACL should match, in the same expression language used for the
match column in the OVN Southbound database’s Logical_Flow table. The outport
logical port is only available in the to-lport direction (the inport is available
in both directions).

By default all traffic is allowed. When writing a more restrictive policy, it is
important to remember to allow flows such as ARP and IPv6 neighbor discovery
packets.

Note that you can not create an ACL matching on a port with type=router.

action: string, one of allow-related, drop, allow, or reject
The action to take when the ACL rule matches:

• allow: Forward the packet.

• allow-related: Forward the packet and related traffic (e.g. inbound replies
to an outbound connection).

• drop: Silently drop the packet.

• reject: Drop the packet, replying with a RST for TCP or ICMP unreachable
message for other IP-based protocols. Not implemented--currently treated as
drop

log: boolean
If set to true, packets that match the ACL will trigger a log message on the
transport node or nodes that perform ACL processing. Logging may be combined with
any action.

Logging is not yet implemented.

Common Columns:

external_ids: map of string-string pairs
See External IDs at the beginning of this document.

Logical_Router TABLE

       Each row represents one L3 logical router.

   Summary:
       name                          string
       ports                         set of Logical_Router_Ports
       default_gw                    optional string
       Common Columns:
         external_ids                map of string-string pairs

   Details:
       name: string
              A  name  for the logical router.  This name has no special meaning or purpose other
              than to provide convenience for human interaction with the ovn-nb database.   There
              is  no  requirement for the name to be unique.  The logical router’s UUID should be
              used as the unique identifier.

       ports: set of Logical_Router_Ports
              The router’s ports.

       default_gw: optional string
              IP address to use as default gateway, if any.

     Common Columns:

       external_ids: map of string-string pairs
              See External IDs at the beginning of this document.

Logical_Router_Port TABLE

A port within an L3 logical router.

Exactly one Logical_Router row must reference a given logical router port.

Summary:
name string (must be unique within table)
network string
mac string
enabled optional boolean
Attachment:
peer optional Logical_Router_Port
Common Columns:
external_ids map of string-string pairs

Details:
name: string (must be unique within table)
A name for the logical router port.

In addition to provide convenience for human interaction with the ovn-nb database,
this column is used as reference by its patch port in Logical_Port or another
logical router port in Logical_Router_Port.

network: string
The IP address of the router and the netmask. For example, 192.168.0.1/24
indicates that the router’s IP address is 192.168.0.1 and that packets destined to
192.168.0.x should be routed to this port.

mac: string
The Ethernet address that belongs to this router port.

Attachment:
A given router port serves one of two purposes:

• To attach a logical switch to a logical router. A logical router port of
this type is referenced by exactly one Logical_Port of type router. The
value of name is set as router-port in column options of Logical_Port. In
this case peer column is empty.

• To connect one logical router to another. This requires a pair of logical
router ports, each connected to a different router. Each router port in the
pair specifies the other in its peer column. No Logical_Switch refers to
the router port.

peer: optional Logical_Router_Port
For a router port used to connect two logical routers, this identifies the other
router port in the pair by name.

For a router port attached to a logical switch, this column is empty.

Common Columns:

external_ids: map of string-string pairs
See External IDs at the beginning of this document.