OVN on Linux, FreeBSD and NetBSD¶
This document describes how to build and install OVN on a generic Linux, FreeBSD, or NetBSD host. For specifics around installation on a specific platform, refer to one of the other installation guides listed in Installing Open vSwitch.
Obtaining OVN Sources¶
The canonical location for OVN source code is its Git repository, which you can clone into a directory named “ovn” with:
$ git clone https://github.com/ovn-org/ovn.git
Cloning the repository leaves the “master” branch initially checked out. This is the right branch for general development.
As of now there are no official OVN releases.
Before building OVN you should configure and build OVS. Please see the Open vSwitch documentation (https://docs.openvswitch.org/en/latest/intro/install/) to build and install OVS https://github.com/openvswitch/ovs.git
To compile the userspace programs in the OVN distribution, you will need the following software:
- GNU make
- A C compiler, such as:
- GCC 4.6 or later.
- Clang 3.4 or later.
- MSVC 2013. Refer to OVN on Windows for additional Windows build instructions.
- While OVN may be compatible with other compilers, optimal support for atomic
operations may be missing, making OVN very slow
- libssl, from OpenSSL, is optional but recommended if you plan to connect the OVN services to the OVN DB ovsdb-servers securely. If libssl is installed, then OVN will automatically build with support for it.
- Python 2.7. You must also have the Python
sixlibrary version 1.4.0 or later.
- Unbound library, from http://www.unbound.net, is optional but recommended if you want to enable ovn-northd, ovn-controller and other utilities to use DNS names when specifying OVSDB remotes. If unbound library is already installed, then OVN will automatically build with support for it. The environment variable OVS_RESOLV_CONF can be used to specify DNS server configuration file (the default file on Linux is /etc/resolv.conf).
If you are working from a Git tree or snapshot (instead of from a distribution tarball), or if you modify the OVN build system or the database schema, you will also need the following software:
- Autoconf version 2.63 or later.
- Automake version 1.10 or later.
- libtool version 2.4 or later. (Older versions might work too.)
The OVN manpages will include an E-R diagram, in formats other than plain text, only if you have the following:
- dot from graphviz (http://www.graphviz.org/).
If you are going to extensively modify OVN, consider installing the following to obtain better warnings:
- “sparse” version 0.5.1 or later (https://git.kernel.org/pub/scm/devel/sparse/sparse.git/).
- GNU make.
- clang, version 3.4 or later
- flake8 along with the hacking flake8 plugin (for Python code). The automatic flake8 check that runs against Python code has some warnings enabled that come from the “hacking” flake8 plugin. If it’s not installed, the warnings just won’t occur until it’s run on a system with “hacking” installed.
You may find the ovs-dev script found in
The machine you build OVN on may not be the one you run it on. To simply install and run OVN you require the following software:
- Shared libraries compatible with those used for the build.
- Python 2.7. You must also have the Python six library version 1.4.0 or later.
On Linux you should ensure that
/dev/urandom exists. To support TAP
devices, you must also ensure that
This step is not needed if you have downloaded a released tarball. If you pulled the sources directly from an Open vSwitch Git tree or got a Git tree snapshot, then run boot.sh in the top source directory to build the “configure” script:
Before configuring OVN, clone, configure and build Open vSwitch.
Configure the package by running the configure script. You need to invoke configure with atleast the argument –with-ovs-source. For example:
$ ./configure --with-ovs-source=/path/to/ovs/source
If you have built Open vSwitch in a separate directory, then you need to provide that path in the option - –with-ovs-build.
By default all files are installed under
/usr/local. OVN expects to find
its database in
/usr/local/etc/ovn by default.
If you want to install all files into, e.g.,
/var instead of
/usr/local/var and expect to use
the default database directory, add options as shown here:
$ ./configure --prefix=/usr --localstatedir=/var --sysconfdir=/etc
OVN installed with packages like .rpm (e.g. via
yum install or
rpm -ivh) and .deb (e.g. via
apt-get install or
dpkg -i) use the above configure options.
By default, static libraries are built and linked against. If you want to use shared libraries instead:
$ ./configure --enable-shared
To use a specific C compiler for compiling Open vSwitch user programs, also specify it on the configure command line, like so:
$ ./configure CC=gcc-4.2
To use ‘clang’ compiler:
$ ./configure CC=clang
To supply special flags to the C compiler, specify them as
CFLAGS on the
configure command line. If you want the default CFLAGS, which include
build debug symbols and
-O2 to enable optimizations, you must include them
yourself. For example, to build with the default CFLAGS plus
might run configure as follows:
$ ./configure CFLAGS="-g -O2 -mssse3"
For efficient hash computation special flags can be passed to leverage built-in
intrinsics. For example on X86_64 with SSE4.2 instruction set support, CRC32
intrinsics can be used by passing
$ ./configure CFLAGS="-g -O2 -msse4.2"`
Also builtin popcnt instruction can be used to speedup the counting of the
bits set in an integer. For example on X86_64 with POPCNT support, it can be
enabled by passing
$ ./configure CFLAGS="-g -O2 -mpopcnt"`
If you are on a different processor and don’t know what flags to choose, it is
recommended to use
$ ./configure CFLAGS="-g -O2 -march=native"
With this, GCC will detect the processor and automatically set appropriate flags for it. This should not be used if you are compiling OVS outside the target machine.
CFLAGS are not applied when building the Linux kernel module. Custom CFLAGS
for the kernel module are supplied using the
EXTRA_CFLAGS variable when
running make. For example:
$ make EXTRA_CFLAGS="-Wno-error=date-time"
If you are a developer and want to enable Address Sanitizer for debugging
purposes, at about a 2x runtime cost, you can add
-fsanitize=address -fno-omit-frame-pointer -fno-common to CFLAGS. For
$ ./configure CFLAGS="-g -O2 -fsanitize=address -fno-omit-frame-pointer -fno-common"
To build the Linux kernel module, so that you can run the kernel-based switch,
pass the location of the kernel build directory on
example, to build for a running instance of Linux:
$ ./configure --with-linux=/lib/modules/$(uname -r)/build
--with-linux requests building for an unsupported version of Linux,
configure will fail with an error message. Refer to the
Open vSwitch FAQ for advice in that case.
If you plan to do much OVN development, you might want to add
--enable-Werror, which adds the
-Werror option to the compiler command
line, turning warnings into errors. That makes it impossible to miss warnings
generated by the build. For example:
$ ./configure --enable-Werror
If you’re building with GCC, then, for improved warnings, install
(see “Prerequisites”) and enable it for the build by adding
--enable-sparse. Use this with
--enable-Werror to avoid missing both
sparse warnings, e.g.:
$ ./configure --enable-Werror --enable-sparse
To build with gcov code coverage support, add
$ ./configure --enable-coverage
The configure script accepts a number of other options and honors additional
environment variables. For a full list, invoke configure with the
$ ./configure --help
You can also run configure from a separate build directory. This is helpful if you want to build OVN in more than one way from a single source directory, e.g. to try out both GCC and Clang builds. For example:
$ mkdir _gcc && (cd _gcc && ./configure CC=gcc) $ mkdir _clang && (cd _clang && ./configure CC=clang)
Under certain loads the ovsdb-server and other components perform better when using the jemalloc memory allocator, instead of the glibc memory allocator. If you wish to link with jemalloc add it to LIBS:
$ ./configure LIBS=-ljemalloc
- Example usage::
$ # Clone OVS repo $cd /home/foo/ovs $./boot.sh $mkdir _gcc $cd _gcc && ../configure && cd .. $make -C _gcc
$ # Clone OVN repo $cd /home/foo/ovn $./boot.sh $./configure –with-ovs-source=/home/foo/ovs/ –with-ovs-build=/home/foo/ovs/_gcc
It is expected to configure both Open vSwitch and OVN with the same prefix.
Run GNU make in the build directory, e.g.:
or if GNU make is installed as “gmake”:
If you used a separate build directory, run make or gmake from that directory, e.g.:
$ make -C _gcc $ make -C _clang
Some versions of Clang and ccache are not completely compatible. If you see unusual warnings when you use both together, consider disabling ccache.
Consider running the testsuite. Refer to Testing for instructions.
make installto install the executables and manpages into the running system, by default under
$ make install
Before starting the OVN, start the Open vSwitch daemons. Refer to the Open vSwitch documentation for more details on how to start OVS.
On Unix-alike systems, such as BSDs and Linux, starting the OVN suite of daemons is a simple process. OVN includes a shell script, called ovn-ctl which automates much of the tasks for starting and stopping ovn-northd, ovn-controller and ovsdb-servers. After installation, the daemons can be started by using the ovn-ctl utility. This will take care to setup initial conditions, and start the daemons in the correct order. The ovn-ctl utility is located in ‘$(pkgdatadir)/scripts’, and defaults to ‘/usr/local/share/ovn/scripts’. ovn-ctl utility requires the ‘ovs-lib’ helper shell script which is present in ‘/usr/local/share/openvswitch/scripts’. So invoking ovn-ctl as “./ovn-ctl” will fail.
An example after install might be:
$ export PATH=$PATH:/usr/local/share/ovn/scripts $ ovn-ctl start_northd $ ovn-ctl start_controller
Starting OVN Central services¶
OVN central services includes ovn-northd, Northbound and Southbound ovsdb-server.
$ export PATH=$PATH:/usr/local/share/ovn/scripts $ ovn-ctl start_northd
Refer to ovn-ctl(8) for more information and the supported options.
You may wish to manually start the OVN central daemons. Before starting ovn-northd you need to start OVN Northbound and Southbound ovsdb-servers. Before ovsdb-servers can be started, configure the Northbound and Southbound databases:
$ mkdir -p /usr/local/etc/ovn $ ovsdb-tool create /usr/local/etc/ovn/ovnnb_db.db \ ovn-nb.ovsschema $ ovsdb-tool create /usr/local/etc/ovn/ovnsb_db.db \ ovn-sb.ovsschema
Configure ovsdb-servers to use databases created above, to listen on a Unix domain socket and to use the SSL configuration in the database:
$ mkdir -p /usr/local/var/run/ovn $ ovsdb-server --remote=punix:/usr/local/var/run/ovn/ovnnb_db.sock \ --remote=db:OVN_Northbound,NB_Global,connections \ --private-key=db:OVN_Northbound,SSL,private_key \ --certificate=db:OVN_Northbound,SSL,certificate \ --bootstrap-ca-cert=db:OVN_Northbound,SSL,ca_cert \ --pidfile --detach --log-file $ovsdb-server --remote=punix:/usr/local/var/run/ovn/ovnsb_db.sock \ --remote=db:OVN_Southbound,SB_Global,connections \ --private-key=db:OVN_Southbound,SSL,private_key \ --certificate=db:OVN_Southbound,SSL,certificate \ --bootstrap-ca-cert=db:OVN_Southbound,SSL,ca_cert \ --pidfile --detach --log-file
If you built OVN without SSL support, then omit
Initialize the databases using ovn-nbctl and ovn-sbctl. This is only necessary the first time after you create the databases with ovsdb-tool, though running it at any time is harmless:
$ ovn-nbctl --no-wait init $ ovn-sbctl --no-wait init
Start the ovn-northd, telling it to connect to the OVN db servers same Unix domain socket:
$ ovn-northd --pidfile --detach --log-file
Starting OVN Central services in containers¶
For OVN central node, we dont need to load ovs kernel modules on host. Hence, OVN central containers OS need not depend on host OS.
Also we can leverage deploying entire OVN control plane in a pod spec for use cases like OVN-kubernetes
Export following variables in .env and place it under project root:
$ OVN_BRANCH=<BRANCH> $ OVN_VERSION=<VERSION> $ DISTRO=<LINUX_DISTRO> $ KERNEL_VERSION=<LINUX_KERNEL_VERSION> $ GITHUB_SRC=<GITHUB_URL> $ DOCKER_REPO=<REPO_TO_PUSH_IMAGE>
To build ovn modules:
$ cd utilities/docker $ make build
Compiled Modules will be tagged with docker image
To Push ovn modules:
$ make push
OVN docker image will be pushed to specified docker repo.
Start OVN containers using below command:
$ docker run -itd --net=host --name=ovn-nb \ <docker_repo>:<tag> ovn-nb-tcp $ docker run -itd --net=host --name=ovn-sb \ <docker_repo>:<tag> ovn-sb-tcp $ docker run -itd --net=host --name=ovn-northd \ <docker_repo>:<tag> ovn-northd-tcp
Start OVN containers in cluster mode for a 3 node cluster using below command on node1:
$ docker run -e "host_ip=<host_ip>" -e "nb_db_port=<port>" -itd \ --name=ovn-nb-raft --net=host --privileged <docker_repo>:<tag> \ ovn-nb-cluster-create $ docker run -e "host_ip=<host_ip>" -e "sb_db_port=<port>" -itd \ --name=ovn-sb-raft --net=host --privileged <docker_repo>:<tag> \ ovn-sb-cluster-create $ docker run -e "OVN_NB_DB=tcp:<node1>:6641,tcp:<node2>:6641,\ tcp:<node3>:6641" -e "OVN_SB_DB=tcp:<node1>:6642,tcp:<node2>:6642,\ tcp:<node3>:6642" -itd --name=ovn-northd-raft <docker_repo>:<tag> \ ovn-northd-cluster
Start OVN containers in cluster mode using below command on node2 and node3 to make them join the peer using below command:
$ docker run -e "host_ip=<host_ip>" -e "remote_host=<remote_host_ip>" \ -e "nb_db_port=<port>" -itd --name=ovn-nb-raft --net=host \ --privileged <docker_repo>:<tag> ovn-nb-cluster-join $ docker run -e "host_ip=<host_ip>" -e "remote_host=<remote_host_ip>" \ -e "sb_db_port=<port>" -itd --name=ovn-sb-raft --net=host \ --privileged <docker_repo>:<tag> ovn-sb-cluster-join $ docker run -e "OVN_NB_DB=tcp:<node1>:6641,tcp:<node2>:6641,\ tcp:<node3>:6641" -e "OVN_SB_DB=tcp:<node1>:6642,tcp:<node2>:6642,\ tcp:<node3>:6642" -itd --name=ovn-northd-raft <docker_repo>:<tag> \ ovn-northd-cluster
Start OVN containers using unix socket:
$ docker run -itd --net=host --name=ovn-nb \ -v /var/run/ovn/:/var/run/ovn/ \ <docker_repo>:<tag> ovn-nb $ docker run -itd --net=host --name=ovn-sb \ -v /var/run/ovn/:/var/run/ovn/ <docker_repo>:<tag> ovn-sb $ docker run -itd --net=host --name=ovn-northd \ -v /var/run/ovn/:/var/run/ovn/ <docker_repo>:<tag> ovn-northd
Current ovn central components comes up in docker image in a standalone and cluster mode with protocol tcp.
The debian docker file use ubuntu 16.04 as a base image for reference.
User can use any other base image for debian, e.g. u14.04, etc.
RHEL based docker support is now added with centos7 as a base image.
Starting OVN host service¶
On each chassis, ovn-controller service should be started. ovn-controller assumes it gets configuration information from the Open_vSwitch table of the local OVS instance. Refer to the ovn-controller(8) for the configuration keys.
Below are the required keys to be configured on each chassis.
You may wish to manually start the ovn-controller service on each chassis.
Start the ovn-controller, telling it to connect to the local ovsdb-server Unix domain socket:
$ ovn-controller --pidfile --detach --log-file
Starting OVN host service in containers¶
For OVN host too, we dont need to load ovs kernel modules on host. Hence, OVN host container OS need not depend on host OS.
Also we can leverage deploying OVN host in a pod spec for use cases like OVN-kubernetes to manage OVS which can be running as a service on host or in container.
Start ovsdb-server and ovs-vswitchd components as per http://docs.openvswitch.org/en/latest/intro/install/general/
start local ovn-controller with below command if ovs is also running in container:
$ docker run -itd --net=host --name=ovn-controller \ --volumes-from=ovsdb-server \ <docker_repo>:<tag> ovn-controller
start local ovn-controller with below command if ovs is running as a service:
$ docker run -itd --net=host --name=ovn-controller \ -v /var/run/openvswitch/:/var/run/openvswitch/ \ <docker_repo>:<tag> ovn-controller
At this point you can use ovn-nbctl on the central node to set up logical
switches and ports and other OVN logical entities. For example, to create a
sw0 and add logical port
$ ovn-nbctl ls-add sw0 $ ovn-nbctl lsp-add sw0 sw0-p1 $ ovn-nbctl show
Refer to ovn-nbctl(8) and ovn-sbctl (8) for more details.
When using ovn in container, exec to container to run above commands:
$ docker exec -it <ovn-nb/ovn-sb/ovn-northd/ovn-controller> /bin/bash