Page tree

Have questions? Stuck? Please check our FAQ for some common questions and answers.

Skip to end of metadata
Go to start of metadata

Python2 and Python3

Both Python2 and Python3 are required for some build tools



Install Python
sudo apt install python
sudo apt install python3
sudo apt install python-pip python-dev python-setuptools
sudo apt install python3-pip python3-dev python3-setuptools

pip3 install --upgrade pip
pip3 install selenium



Git and git-review

Git and git-review will be used to pull and push code from/to the ONOS repository, so they need to be installed. To streamline the code review process, it is highly recommended that contributors install git-review

Install git and git-review
sudo apt-get install git
sudo apt-get install git-review


git-review on Mac

For more info about git-review refer to this link

If you're using a Mac, you may need to manually upgrade the git-review package dependency. (git-review bug#1337701)

$ sudo pip install --upgrade setuptools
$ sudo pip install --upgrade git-review

Install Bazelisk

ONOS is a large project comprising of multiple relatively independent modules that lend themselves to be built in parallel, resulting in much faster. This is why the project chose to build via Bazel.

Bazelisk is a tool that manages multiple versions of Bazel. Different versions of ONOS have been verified on different versions of Bazel (as defined in their .bazelversion file). Using Bazel will ensure that you will build against the version of Bazel suitable for the release you are building on.

Developers should install Bazelisk(1.4.0 or greater at the time of writing) before they can build the project themselves.

Bazelisk should be downloaded and installed as a drop in replacement for the "bazel" command. It is recommended not to download Bazel directly yourself - let Bazelisk get the right version for you!

On Linux use

$ wget https://github.com/bazelbuild/bazelisk/releases/download/v1.4.0/bazelisk-linux-amd64
$ chmod +x bazelisk-linux-amd64
$ sudo mv bazelisk-linux-amd64 /usr/local/bin/bazel
$ cd ~/onos
$ bazel version

Alternatively, on macOS, Bazelisk can be installed via the Brew package manager:

$ brew install bazelisk
$ ln -s $(which bazelisk) /usr/local/bin/bazel # Create symlink to use as a drop-in replacement to the bazel command
$ cd ~/onos
$ bazel version


Calling "bazel version" causes Bazelisk to download Bazel and runs the "version" command on it. Bazelisk acts transparently and any command line arguments will be passed straight through to Bazel.

Behind the scenes, Bazelisk caches downloaded Bazel versions in ~/.cache/bazelisk/

Versions of Bazel can be preloaded using

$USE_BAZEL_VERSION=1.2.1 bazel version


  • No labels