packages/net/openvswitch
Yousong Zhou 52e074411b openvswitch: only libopenvswitch depends on libunbound, libunwind
This is to make explicit the conditional select of libunwind is only
needed for libopenvswitch.  If we spill it over other packages, the
generated kconfig will have recursive dependency issue.  2 new patches
were made for this goal

The other thing is that "+libunwind" will cause it to be built if any of the
packages defined in this Makefile is enabled (y or m).  This is at the moment
by-design of the build system.

Libunwind does not support architectures like arc.  Use conditional select To
avoid (libunwind) build failures like the following,

  checking for ELF helper width... configure: error: Unknown ELF target: arc
  make[3]: *** [Makefile:65: /data/openwrt/build_dir/target-arc_arc700_uClibc/
  libunwind-1.3.1/.configured_68b329da9893e34099c7d8ad5cb9c940] Error 1

Things like "+PACKAGE_openvswitch-libopenvswitch:libunwind" will also result in
recursive deps error for chains of 3 nodes.  Kconfig construct like the
following will be made

	config A
		tristate
		select B
		depends on !(C) || (x)

	config B
		tristate
		select C

	config C
		tristate

	config x
		bool

Other changes include

 - Shared use of variable ovs__common_depends was removed
 - Ovn doc build was patched out

Link: https://github.com/openwrt/packages/pull/12959#issuecomment-665021413
Reported-by: Adrian Schmutzler <freifunk@adrianschmutzler.de>
Signed-off-by: Yousong Zhou <yszhou4tech@gmail.com>
2020-07-30 10:02:13 +08:00
..
files openvswitch: adds new UCI section ovs_bridge 2020-07-28 12:46:17 +08:00
patches openvswitch: only libopenvswitch depends on libunbound, libunwind 2020-07-30 10:02:13 +08:00
Makefile openvswitch: only libopenvswitch depends on libunbound, libunwind 2020-07-30 10:02:13 +08:00
openvswitch.mk openvswitch: only libopenvswitch depends on libunbound, libunwind 2020-07-30 10:02:13 +08:00
README.md openvswitch: adds new UCI section ovs_bridge 2020-07-28 12:46:17 +08:00

Which packages to install

Install openvswitch if you need OpenFlow virtual switch function. It contains ovs-vswitchd, ovsdb-server and helper utilities such as ovs-vsctl, ovs-ofctl, ovs-ctl etc.

Linux kernel datapath module openvswitch.ko will also be installed along with package openvswitch. Tunnel encap support for gre, geneve, vxlan can be included by installing kmod-openvswitch-{gre,geneve,vxlan} respectively

For OVN deployment

  • Install openvswitch-ovn-north for ovs-northd, ovsdb-server, ovn helper utitlies
  • Install openvswitch-ovn-host for ovn-controller and openvswitch

How to use them

Open vSwitch provides a few very useful helper script in /usr/share/openvswitch/scripts/. A simple initscript is provided. It's mainly a wrapper around ovs-ctl and ovn-ctl with simple knobs from /etc/config/openvswitch. Procd is not used here.

/etc/init.d/openvswitch start
/etc/init.d/openvswitch stop
/etc/init.d/openvswitch stop north
/etc/init.d/openvswitch restart ovs
/etc/init.d/openvswitch status

Use ovs-ctl and ovn-ctl directly for more functionalities

Open vSwitch in-tree Linux datapath modules

The Open vSwitch build system uses regexp and conditional-compilation heuristics to support building the shipped kernel module source code against a wide range of kernels, as of openvswitch-2.10, the list is supposed to include vanilla linux 3.10 to 4.15, plus a few distro kernels.

It may NOT work

  • Sometimes the code does not compile
  • Sometimes the code compiles but insmod will fail
  • Sometimes modules are loaded okay but actually does not function right

For these reasons, the in-tree datapath modules are NOT visible/enabled by default.

Building and using in-tree datapath modules requires some level of devel abilities to proceed. You are expected to configure build options and build the code on your own

E.g. pair openvswitch userspace with in-tree datapath module

CONFIG_DEVEL=y
CONFIG_PACKAGE_openvswitch=y
# CONFIG_PACKAGE_kmod-openvswitch is not set
CONFIG_PACKAGE_kmod-openvswitch-intree=y

E.g. replace in-tree datapath module with upstream version

opkg remove --force-depends kmod-openvswitch-intree
opkg install kmod-openvswitch
ovs-ctl force-reload-kmod

UCI configuration options

There are 4 config section types in package openvswitch: ovs ovn_northd, ovn_controller & ovs_bridge.

Each of these supports a disabled option, which should be set to 0 to launch the respective daemons.

The ovs_bridge section also supports the options below, for initialising a virtual bridge with an OpenFlow controller.

Name Type Required Default Description
disabled boolean no 0 If set to true, disable initialisation of the named bridge
name string no Inherits UCI config block name The name of the switch in the OVS daemon
controller string no (none) The endpoint of an OpenFlow controller for this bridge