# RHEL 5.6, 6.x Packaging for Open vSwitch

This document describes how to build and install Open vSwitch on a Red Hat Enterprise Linux (RHEL) host. If you want to install Open vSwitch on a generic Linux host, refer to Open vSwitch on Linux, FreeBSD and NetBSD instead.

We have tested these instructions with RHEL 5.6 and RHEL 6.0.

For RHEL 7.x (or derivatives, such as CentOS 7.x), you should follow the instructions in the Fedora, RHEL 7.x Packaging for Open vSwitch. The Fedora spec files are used for RHEL 7.x.

## Prerequisites

You may build from an Open vSwitch distribution tarball or from an Open vSwitch Git tree.

The default RPM build directory, `_topdir`, has five directories in the top-level.

BUILD/

  where the software is unpacked and built

RPMS/

  where the newly created binary package files are written

SOURCES/

  contains the original sources, patches, and icon files

SPECS/

  contains the spec files for each package to be built

SRPMS/

  where the newly created source package files are written

Before you begin, note the RPM sources directory on your version of RHEL. The command `rpmbuild --showrc` will show the configuration for each of those directories. Alternatively, the command `rpm --eval '%{_topdir}'` shows the current configuration for the top level directory and the command `rpm --eval '%{_sourcedir}'` does the same for the sources directory. On RHEL 5, the default RPM `_topdir` is `/usr/src/redhat` and the default RPM sources directory is `/usr/src/redhat/SOURCES`. On RHEL 6, the default `_topdir` is `$HOME/rpmbuild` and the default RPM sources directory is `$HOME/rpmbuild/SOURCES`.

## Build Requirements

You will need to install all required packages to build the RPMs. The command below will install RPM tools and generic build dependencies:

    $ yum install @'Development Tools' rpm-build yum-utils

Then it is necessary to install Open vSwitch specific build dependencies. The dependencies are listed in the SPEC file, but first it is necessary to replace the VERSION tag to be a valid SPEC.

The command below will create a temporary SPEC file:

    $ sed -e 's/@VERSION@/0.0.1/' rhel/openvswitch.spec.in > /tmp/ovs.spec

And to install specific dependencies, use yum-builddep tool:

    $ yum-builddep /tmp/ovs.spec

Once that is completed, remove the file `/tmp/ovs.spec`.

If python3-sphinx package is not available in your version of RHEL, you can install it via pip with ‘pip install sphinx’.

Open vSwitch requires python 3.4 or newer which is not available in older distributions. In the case of RHEL 6.x and its derivatives, one option is to install python34 from EPEL.

## Bootstrapping and Configuring

If you are building from a distribution tarball, skip to Building. If not, you must be building from an Open vSwitch Git tree. Determine what version of Autoconf is installed (e.g. run `autoconf --version`). If it is not at least version 2.63, then you must upgrade or use another machine to build the packages.

Assuming all requirements have been met, build the tarball by running:

    $ ./boot.sh
    $ ./configure
    $ make dist

You must run this on a machine that has the tools listed in Build Requirements as prerequisites for building from a Git tree. Afterward, proceed with the rest of the instructions using the distribution tarball.

Now you have a distribution tarball, named something like `openvswitch-x.y.z.tar.gz`. Copy this file into the RPM sources directory, e.g.:

    $ cp openvswitch-x.y.z.tar.gz $HOME/rpmbuild/SOURCES

### Broken `build` symlink

Some versions of the RHEL 6 kernel-devel package contain a broken `build` symlink. If you are using such a version, you must fix the problem before continuing.

To find out whether you are affected, run:

    $ cd /lib/modules/<version>
    $ ls -l build/

where `<version>` is the version number of the RHEL 6 kernel.

Note

The trailing slash in the final command is important. Be sure to include it.

If the `ls` command produces a directory listing, your kernel-devel package is OK. If it produces a `No such file or directory` error, your kernel-devel package is buggy.

If your kernel-devel package is buggy, then you can fix it with:

    $ cd /lib/modules/<version>
    $ rm build
    $ ln -s /usr/src/kernels/<target> build

where `<target>` is the name of an existing directory under `/usr/src/kernels`, whose name should be similar to `<version>` but may contain some extra parts. Once you have done this, verify the fix with the same procedure you used above to check for the problem.

## Building

You should have a distribution tarball named something like openvswitch-x.y.z.tar.gz. Copy this file into the RPM sources directory:

    $ cp openvswitch-x.y.z.tar.gz $HOME/rpmbuild/SOURCES

Make another copy of the distribution tarball in a temporary directory. Then unpack the tarball and `cd` into its root:

    $ tar xzf openvswitch-x.y.z.tar.gz
    $ cd openvswitch-x.y.z

### Userspace

To build Open vSwitch userspace, run:

    $ rpmbuild -bb rhel/openvswitch.spec

This produces two RPMs: “openvswitch” and “openvswitch-debuginfo”.

The above command automatically runs the Open vSwitch unit tests. To disable the unit tests, run:

    $ rpmbuild -bb --without check rhel/openvswitch.spec

Note

If the build fails with `configure: error: source dir /lib/modules/2.6.32-279.el6.x86_64/build doesn't exist` or similar, then the kernel-devel package is missing or buggy.

### Kernel Module

On RHEL 6, to build the Open vSwitch kernel module run:

    $ rpmbuild -bb rhel/kmod-openvswitch-rhel6.spec

You might have to specify a kernel version and/or variants, e.g.:

    $ rpmbuild -bb \
        -D "kversion 2.6.32-131.6.1.el6.x86_64" \
        -D "kflavors default debug kdump" \
        rhel/kmod-openvswitch-rhel6.spec

This produces an “kmod-openvswitch” RPM for each kernel variant, in this example: “kmod-openvswitch”, “kmod-openvswitch-debug”, and “kmod-openvswitch-kdump”.

## Red Hat Network Scripts Integration

A RHEL host has default firewall rules that prevent any Open vSwitch tunnel traffic from passing through. If a user configures Open vSwitch tunnels like Geneve, GRE, VXLAN, LISP etc., they will either have to manually add iptables firewall rules to allow the tunnel traffic or add it through a startup script Refer to the “enable-protocol” command in the ovs-ctl(8) manpage for more information.

In addition, simple integration with Red Hat network scripts has been implemented. Refer to README.RHEL.rst in the source tree or /usr/share/doc/openvswitch/README.RHEL.rst in the installed openvswitch package for details.

## Reporting Bugs

Report problems to bugs@openvswitch.org.