Getting started with Unikraft

The easiest way to get started with Unikraft is to use the command-line utility kraft, which is a companion tool used for defining, configuring, building, and running Unikraft applications. With kraft you can seamlessly create a build environment for your unikernel and painlessly manage dependencies for its build.

Installing the CLI companion tool kraft

The kraft tool and Unikraft build system have a number of package requirements; please run the following command (on apt-get-based systems) to install the requirements:

apt-get install -y --no-install-recommends \
  build-essential \
  libncurses-dev \
  libyaml-dev \
  flex \
  git \
  wget \
  socat \
  bison \
  unzip \
  uuid-runtime \
  python3 \

To install kraft simply run:

pip3 install git+

You can then type kraft to see its help menu:

Usage: kraft [OPTIONS] COMMAND [ARGS]...

  --version         Show the version and exit.
  -C, --no-color    Do not use colour in output logs.
  -T, --timestamps  Show timestamps in output logs.
  -Y, --yes         Assume yes to any binary prompts.
  -v, --verbose     Enables verbose mode.
  -h, --help        Show this message and exit.

  build       Build the application.
  clean       Clean the application.
  configure   Configure the application.
  fetch       Fetch library dependencies.
  init        Initialize a new unikraft application.
  lib         Unikraft library commands.
  list        List architectures, platforms, libraries or applications.
  menuconfig  Open the KConfig Menu editor
  prepare     Runs preparations steps on libraries.
  run         Run the application.
  up          Configure, build and run an application.

Influential Environmental Variables:
  UK_WORKDIR The working directory for all Unikraft
  source code [default: ~/.unikraft]
  UK_ROOT    The directory for Unikraft's core source
  code [default: $UK_WORKDIR/unikraft]
  UK_LIBS    The directory of all the external Unikraft
  libraries [default: $UK_WORKDIR/libs]
  UK_APPS    The directory of all the template applications
  [default: $UK_WORKDIR/apps]
  KRAFTRC  The location of kraft's preferences file
  [default: ~/.kraftrc]

  For help using this tool, please open an issue on Github:

Building an Application

The simplest way to get the sources for, build and run an application is by running the following commands:

kraft list

You can also build and run an applications from the existing templates by using the -t option. For example, building and running the helloworld app:

kraft up -p kvm -m x86_64 -t helloworld helloworld

For more information about all the steps behind kraft up, check Creating an App. For more information about the up command type kraft up -h. For more information about kraft type kraft -h or read the documentation at Unikraft’s website. If you find any problems please fill out an issue. Thank you!