libovsdb 1.0.13

An OVSDB Library written in python.

An OVSDB Library written in python.

1. Introduction

OVSDB is the Open vSwitch Database Protocol. It’s defined in RFC 7047 It’s used mainly but not limited for managing the configuration of Open vSwitch and OVN. Recently vendors have begun implementing OVSDB in their Ethernet switches firmware. Some of those vendor data plane implementations are already running OVS under the hood so the implementation should be relatively painless.

This is for operation on ovsdb protocol, not only for Open vSwitch and OVN. Any project with ovsdb protocol can leverage this library.

To use this lib, only need the ovsdb-server running. Take OVS as exampne, if you’re running OVS version 1.10 or later, you can do this using ovs-appctl:

ovs-appctl -t ovsdb-server ovsdb-server/add-remote ptcp:6632

Quick API Examples

connect to ovsdb server

We use url to define an ovsdb server. Now ovsdb-server support unix and tcp access, so they are supported by libovsdb. For example

Connect to the ovsdb server:

#from libovsdb import libovsdb
#ovsdb_server = 'tcp:192.168.1.11:6641'
ovsdb_server = 'unix:/usr/local/var/run/ovn/ovnnb_db.sock'
db = libovsdb.OVSDBConnection(ovsdb_server, "OVN_Northbound")
print(db.list_dbs())

The result is:

{'id': 0, 'result': ['OVN_Northbound', '_Server'], 'error': None}

insert/delete/udpate/select API

insert/delete/udpate/select API provide basice operation for ovsdb db. for example:

#from libovsdb import libovsdb
#ovsdb_server = 'tcp:192.168.1.11:6641'
ovsdb_server = 'unix:/usr/local/var/run/ovn/ovnnb_db.sock'
db = libovsdb.OVSDBConnection(ovsdb_server, "OVN_Northbound")

res = db.insert(table = "Logical_Switch", row = {"name":"ls1"})
cli.log("insert Logical_Switch result: %s" %(json.dumps(res, indent=4)))

res = db.insert(table = "Logical_Switch_Port",
                row = {"name":"ls1-lsp0"},
                refer = ["Logical_Switch", "ports", ["name", "==", "ls1"]])
cli.log("insert Logical_Switch result: %s" %(json.dumps(res, indent=4)))

res = db.update(table = "Logical_Switch_Port",
                row = {"addresses": "00:00:00:00:00:05"},
                where = [["name", "==", "ls1-lsp0"]])
cli.log("update Logical_Switch result: %s" %(json.dumps(res, indent=4)))

res = db.select(table = "Logical_Switch",
                columns = ["_uuid", "name"],
                where = [["name", "==", "ls1"]])
cli.log("select Logical_Switch result: %s" %(json.dumps(res, indent=4)))

res = db.delete(table = "Logical_Switch_Port",
                where = [["name", "==", "ls1-lsp0"]],
                referby = ["Logical_Switch", "ls1", "ports"])
cli.log("delete Logical_Switch_Port result: %s" %(json.dumps(res, indent=4)))

performance mode

We can encapsulate multi operations into one transaction for performance, for example, insert a row, create a transaction and add op into it,then commit:

#from libovsdb import libovsdb
#ovsdb_server = 'tcp:192.168.1.11:6641'
ovsdb_server = 'unix:/usr/local/var/run/ovn/ovnnb_db.sock'
db = libovsdb.OVSDBConnection(ovsdb_server, "OVN_Northbound")
tx = db.transact()

name = tx.insert(table = "Logical_Switch_Port",
                row = {"name":"ls1-lsp0"})
tx.mutate(table = "Logical_Switch",
          where = [["name", "==", "ls1"]],
          mutations = [tx.make_mutations("ports", "insert", {"named-uuid": name})])
response = tx.commit()

print("%s" %(response["result"]))

delete a row, create a transaction and add op into it,then commit:

# Get the uuid in other way, since it's needed in mutate op.
uuid = 03934fdf-6087-48e7-b5ce-54d4d76e4368
tx.delete(table = "Logical_Switch_Port",
        where = [["uuid", "==", uuid]])
tx.mutate(table = "Logical_Switch",
          where = [["name", "==", "ls1"]],
          mutations = [tx.make_mutations("ports", "delete", {"uuid": uuid})])
response = tx.commit()

print("%s" %(response["result"]))

update a row, create a transaction and add op into it,then commit:

#from libovsdb import libovsdb
#ovsdb_server = 'tcp:192.168.1.11:6641'
ovsdb_server = 'unix:/usr/local/var/run/ovn/ovnnb_db.sock'
db = libovsdb.OVSDBConnection(ovsdb_server, "OVN_Northbound")
tx = db.transact()

tx.update(table = "Logical_Switch_Port",
        row = {"addresses": "00:00:00:00:00:05"},
        where = [["name", "==", "ls1-lsp0"]])
response = tx.commit()

print("%s" %(response["result"]))

query some rows, create a transaction and add op into it,then commit:

#from libovsdb import libovsdb
#ovsdb_server = 'tcp:192.168.1.11:6641'
ovsdb_server = 'unix:/usr/local/var/run/ovn/ovnnb_db.sock'
db = libovsdb.OVSDBConnection(ovsdb_server, "OVN_Northbound")
tx = db.transact()

response = tx.row_select(table = "Logical_Switch",
                         columns = ["_uuid", "name"],
                         where = [["name", "==", "ls1"]])
response = tx.commit()

print("%s" %(response["result"]))

Release Notes

1.0.8: Add dryrun option: Don’t really run the ovsdb command, just print it. 1.0.9: Add new API:

OVSDBConnection().insert (self, table, row, **kwargs)
OVSDBConnection().delete (self, table, where, **kwargs)
OVSDBConnection().update (self, table, row, where, **kwargs)
OVSDBConnection().update (self, table, row, where, **kwargs)
OVSDBConnection().select (self, table, where, **kwargs):

1.0.13: 1) Bug fix: select always return empty. 2) Add this change log.