Build and install MicroOVN from source

This how-to contains steps needed for building MicroOVN from its source code. This is useful, for example, if you want to contribute to the MicroOVN and you want to test your changes locally.

Build requirements

MicroOVN is distributed as a snap and the only requirements for building it are Make and snapcraft. You can install them with:

sudo apt install make
sudo snap install snapcraft --classic

Snapcraft requires LXD to build snaps. So if your system does not have LXD installed and initiated, you can check out either LXD getting started guides or go with following default setup:

sudo snap install lxd
lxd init --auto

Build MicroOVN

To build MicroOVN, go into the repository’s root directory and run:

make

This will produce the microovn.snap file that can be then used to install MicroOVN on your system.

Adjust build parameters

snapcraft.yaml is by nature a very static build recipe that does not allow build-time modification without changing the file itself. To achieve some level of control over MicroOVN builds, we are using a microovn/build-aux/environment file that is loaded and during the build process. Environment variables defined in this file can influence properties of the final build. Currently supported variables are:

• MICROOVN_COVERAGE (default: no) - When set to yes, MicroOVN binaries will be built with coverage instrumentation and output coverage data into $SNAP_COMMON/data/coverage.

Install MicroOVN

Using the microovn.snap file created in the previous section, you can install MicroOVN in this way:

sudo snap install --dangerous ./microovn.snap

Note

If you are building latest MicroOVN from the main branch, it’s possible that it’s using a non-stable core snap as its base. In that case, you may get a message like this:

Ensure prerequisites for "microovn" are available (cannot install snap base "core24": no snap revision available as specified)

In such a case, you will need to install the required core snap manually from the edge risk level. For example:

snap install core24 --edge

Then repeat the installation step.

You will also need to manually connect required plugs, as snapd won’t do it automatically for locally installed snaps.

for plug in firewall-control \
             hardware-observe \
             hugepages-control \
             network-control \
             openvswitch-support \
             process-control \
             system-trace; do \
    sudo snap connect microovn:$plug;done

To verify that all the required plugs are correctly connected to their slots, you can run:

snap connections microovn

An example of correctly connected connected plugs would look like this:

Interface            Plug                          Slot                       Notes
content              -                             microovn:ovn-certificates  -
content              -                             microovn:ovn-chassis       -
content              -                             microovn:ovn-env           -
firewall-control     microovn:firewall-control     :firewall-control          manual
hardware-observe     microovn:hardware-observe     :hardware-observe          manual
hugepages-control    microovn:hugepages-control    :hugepages-control         manual
microovn             -                             microovn:microovn          -
network              microovn:network              :network                   -
network-bind         microovn:network-bind         :network-bind              -
network-control      microovn:network-control      :network-control           manual
openvswitch-support  microovn:openvswitch-support  :openvswitch-support       manual
process-control      microovn:process-control      :process-control           manual
system-trace         microovn:system-trace         :system-trace              manual

And if the plugs are not connected, the output would look like this:

Interface            Plug                          Slot                       Notes
content              -                             microovn:ovn-certificates  -
content              -                             microovn:ovn-chassis       -
content              -                             microovn:ovn-env           -
firewall-control     microovn:firewall-control     -                          -
hardware-observe     microovn:hardware-observe     -                          -
hugepages-control    microovn:hugepages-control    -                          -
microovn             -                             microovn:microovn          -
network              microovn:network              :network                   -
network-bind         microovn:network-bind         :network-bind              -
network-control      microovn:network-control      -                          -
openvswitch-support  microovn:openvswitch-support  -                          -
process-control      microovn:process-control      -                          -
system-trace         microovn:system-trace         -                          -