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Document OVN support in ovs-sandbox.
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A previous commit removed the original ovs-sandbox based OVN tutorial
because it became too outdated and difficult to maintain.  However,
the use of ovs-sandbox for basic OVN development and testing is incredibly
useful, so we should provide at least basic documentation on how to use it.

This commit introduces a new and shorter document that shows how to use OVN
in ovs-sandbox.  It provides a single sample configuration, as well as a
sample ovn-trace command.

Signed-off-by: Russell Bryant <[email protected]>
Acked-by: Numan Siddique <[email protected]>
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russellb committed Mar 15, 2017
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1 change: 1 addition & 0 deletions Documentation/automake.mk
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Expand Up @@ -24,6 +24,7 @@ EXTRA_DIST += \
Documentation/intro/install/xenserver.rst \
Documentation/tutorials/index.rst \
Documentation/tutorials/ovs-advanced.rst \
Documentation/tutorials/ovn-sandbox.rst \
Documentation/topics/index.rst \
Documentation/topics/bonding.rst \
Documentation/topics/datapath.rst \
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1 change: 1 addition & 0 deletions Documentation/index.rst
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Expand Up @@ -61,6 +61,7 @@ vSwitch? Start here.
:doc:`intro/install/dpdk`

- **Tutorials:** :doc:`tutorials/ovs-advanced` |
:doc:`tutorials/ovn-sandbox`

Deeper Dive
-----------
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1 change: 1 addition & 0 deletions Documentation/tutorials/index.rst
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Expand Up @@ -40,3 +40,4 @@ vSwitch.
:maxdepth: 2

ovs-advanced
ovn-sandbox
178 changes: 178 additions & 0 deletions Documentation/tutorials/ovn-sandbox.rst
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..
Licensed under the Apache License, Version 2.0 (the "License"); you may
not use this file except in compliance with the License. You may obtain
a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
License for the specific language governing permissions and limitations
under the License.

Convention for heading levels in Open vSwitch documentation:

======= Heading 0 (reserved for the title in a document)
------- Heading 1
~~~~~~~ Heading 2
+++++++ Heading 3
''''''' Heading 4

Avoid deeper levels because they do not render well.

===========
OVN Sandbox
===========

This tutorial shows you how to explore features using ``ovs-sandbox`` as a
simulated test environment. It's assumed that you have an understanding of OVS
before going through this tutorial. Detail about OVN is covered in
ovn-architecture_, but this tutorial lets you quickly see it in action.

Getting Started
---------------

For some general information about ``ovs-sandbox``, see the "Getting Started"
section of the tutorial_.

``ovs-sandbox`` does not include OVN support by default. To enable OVN, you
must pass the ``--ovn`` flag. For example, if running it straight from the ovs
git tree you would run::

$ make sandbox SANDBOXFLAGS="--ovn"

Running the sandbox with OVN enabled does the following additional steps to the
environment:

1. Creates the ``OVN_Northbound`` and ``OVN_Southbound`` databases as described in
`ovn-nb(5)`_ and `ovn-sb(5)`_.

2. Creates a backup server for ``OVN_Southbond`` database. Sandbox launch
screen provides the instructions on accessing the backup database. However
access to the backup server is not required to go through the tutorial.

3. Creates the ``hardware_vtep`` database as described in `vtep(5)`_.

4. Runs the `ovn-northd(8)`_, `ovn-controller(8)`_, and
`ovn-controller-vtep(8)`_ daemons.

5. Makes OVN and VTEP utilities available for use in the environment, including
`vtep-ctl(8)`_, `ovn-nbctl(8)`_, and `ovn-sbctl(8)`_.

Using GDB
---------

GDB support is not required to go through the tutorial. See the "Using GDB"
section of the `tutorial`_ for more info. Additional flags exist for launching
the debugger for the OVN programs::

--gdb-ovn-northd
--gdb-ovn-controller
--gdb-ovn-controller-vtep

Creating OVN Resources
----------------------

Once you have ``ovs-sandbox`` running with OVN enabled, you can start using OVN
utilities to create resources in OVN. As an example, we will create an
environment that has two logical switches connected by a logical router.

Create the first logical switch with one port::

$ ovn-nbctl ls-add sw0
$ ovn-nbctl lsp-add sw0 sw0-port1
$ ovn-nbctl lsp-set-addresses sw0-port1 "50:54:00:00:00:01 192.168.0.2"

Create the second logical switch with one port::

$ ovn-nbctl ls-add sw1
$ ovn-nbctl lsp-add sw1 sw1-port1
$ ovn-nbctl lsp-set-addresses sw1-port1 "50:54:00:00:00:03 11.0.0.2"

Create the logical router and attach both logical switches::

$ ovn-nbctl lr-add lr0
$ ovn-nbctl lrp-add lr0 lrp0 00:00:00:00:ff:01 192.168.0.1/24
$ ovn-nbctl lsp-add sw0 lrp0-attachment
$ ovn-nbctl lsp-set-type lrp0-attachment router
$ ovn-nbctl lsp-set-addresses lrp0-attachment 00:00:00:00:ff:01
$ ovn-nbctl lsp-set-options lrp0-attachment router-port=lrp0
$ ovn-nbctl lrp-add lr0 lrp1 00:00:00:00:ff:02 11.0.0.1/24
$ ovn-nbctl lsp-add sw1 lrp1-attachment
$ ovn-nbctl lsp-set-type lrp1-attachment router
$ ovn-nbctl lsp-set-addresses lrp1-attachment 00:00:00:00:ff:02
$ ovn-nbctl lsp-set-options lrp1-attachment router-port=lrp1

View a summary of OVN's current logical configuration::

$ ovn-nbctl show
switch 1396cf55-d176-4082-9a55-1c06cef626e4 (sw1)
port lrp1-attachment
addresses: ["00:00:00:00:ff:02"]
port sw1-port1
addresses: ["50:54:00:00:00:03 11.0.0.2"]
switch 2c9d6d03-09fc-4e32-8da6-305f129b0d53 (sw0)
port lrp0-attachment
addresses: ["00:00:00:00:ff:01"]
port sw0-port1
addresses: ["50:54:00:00:00:01 192.168.0.2"]
router f8377e8c-f75e-4fc8-8751-f3ea03c6dd98 (lr0)
port lrp0
mac: "00:00:00:00:ff:01"
networks: ["192.168.0.1/24"]
port lrp1
mac: "00:00:00:00:ff:02"
networks: ["11.0.0.1/24"]

The ``tutorial`` directory of the OVS source tree includes a script
that runs all of the commands for you::

$ ./ovn-setup.sh

Using ovn-trace
---------------

Once you have configured resources in OVN, try using ``ovn-trace`` to see
how OVN would process a sample packet through its logical pipeline.

For example, we can trace an IP packet from ``sw0-port1`` to ``sw0-port2``.
The ``--minimal`` output shows each visible action performed on the packet,
which includes:

#. The logical router will decrement the IP TTL field.
#. The logical router will change the source and destination
MAC addresses to reflect the next hop.
#. The packet will be output to ``sw1-port1``.

::

$ ovn-trace --minimal sw0 'inport == "sw0-port1" \
> && eth.src == 50:54:00:00:00:01 && ip4.src == 192.168.0.2 \
> && eth.dst == 00:00:00:00:ff:01 && ip4.dst == 11.0.0.2 \
> && ip.ttl == 64'

# ip,reg14=0x1,vlan_tci=0x0000,dl_src=50:54:00:00:00:01,dl_dst=00:00:00:00:ff:01,nw_src=192.168.0.2,nw_dst=11.0.0.2,nw_proto=0,nw_tos=0,nw_ecn=0,nw_ttl=64
ip.ttl--;
eth.src = 00:00:00:00:ff:02;
eth.dst = 50:54:00:00:00:03;
output("sw1-port1");

The ``ovn-trace`` utility can also provide much more detail on how the packet
would be processed through OVN's logical pipeline, as well as correlate that
to OpenFlow flows programmed by ``ovn-controller``. See the `ovn-trace(8)`_
man page for more detail.


.. _ovn-architecture: http://openvswitch.org/support/dist-docs/ovn-architecture.7.html
.. _Tutorial: :ref:`ovs-advanced`
.. _ovn-nb(5): http://openvswitch.org/support/dist-docs/ovn-nb.5.html
.. _ovn-sb(5): http://openvswitch.org/support/dist-docs/ovn-sb.5.html
.. _vtep(5): http://openvswitch.org/support/dist-docs/vtep.5.html
.. _ovn-northd(8): http://openvswitch.org/support/dist-docs/ovn-northd.8.html
.. _ovn-controller(8): http://openvswitch.org/support/dist-docs/ovn-controller.8.html
.. _ovn-controller-vtep(8): http://openvswitch.org/support/dist-docs/ovn-controller-vtep.8.html
.. _vtep-ctl(8): http://openvswitch.org/support/dist-docs/vtep-ctl.8.html
.. _ovn-nbctl(8): http://openvswitch.org/support/dist-docs/ovn-nbctl.8.html
.. _ovn-sbctl(8): http://openvswitch.org/support/dist-docs/ovn-sbctl.8.html
.. _ovn-trace(8): http://openvswitch.org/support/dist-docs/ovn-trace.8.html
3 changes: 2 additions & 1 deletion tutorial/automake.mk
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Expand Up @@ -5,6 +5,7 @@ EXTRA_DIST += \
tutorial/t-stage1 \
tutorial/t-stage2 \
tutorial/t-stage3 \
tutorial/t-stage4
tutorial/t-stage4 \
tutorial/ovn-setup.sh
sandbox: all
cd $(srcdir)/tutorial && MAKE=$(MAKE) ./ovs-sandbox -b $(abs_builddir) $(SANDBOXFLAGS)
27 changes: 27 additions & 0 deletions tutorial/ovn-setup.sh
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#!/bin/bash

# Create the first logical switch with one port
ovn-nbctl ls-add sw0
ovn-nbctl lsp-add sw0 sw0-port1
ovn-nbctl lsp-set-addresses sw0-port1 "50:54:00:00:00:01 192.168.0.2"

# Create the second logical switch with one port
ovn-nbctl ls-add sw1
ovn-nbctl lsp-add sw1 sw1-port1
ovn-nbctl lsp-set-addresses sw1-port1 "50:54:00:00:00:03 11.0.0.2"

# Create a logical router and attach both logical switches
ovn-nbctl lr-add lr0
ovn-nbctl lrp-add lr0 lrp0 00:00:00:00:ff:01 192.168.0.1/24
ovn-nbctl lsp-add sw0 lrp0-attachment
ovn-nbctl lsp-set-type lrp0-attachment router
ovn-nbctl lsp-set-addresses lrp0-attachment 00:00:00:00:ff:01
ovn-nbctl lsp-set-options lrp0-attachment router-port=lrp0
ovn-nbctl lrp-add lr0 lrp1 00:00:00:00:ff:02 11.0.0.1/24
ovn-nbctl lsp-add sw1 lrp1-attachment
ovn-nbctl lsp-set-type lrp1-attachment router
ovn-nbctl lsp-set-addresses lrp1-attachment 00:00:00:00:ff:02
ovn-nbctl lsp-set-options lrp1-attachment router-port=lrp1

# View a summary of the configuration
ovn-nbctl show

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