Click on Unikraft

This application starts a Click program with Unikraft. Follow the instructions below to set up, configure, build and run Click.

Quick Setup (aka TLDR)

For a quick setup, run the commands below. Note that you still need to install the requirements.

For building and running everything for x86_64, follow the steps below:

git clone https://github.com/unikraft/app-click click
cd click/
mkdir .unikraft
git clone https://github.com/unikraft/unikraft .unikraft/unikraft
git clone https://github.com/unikraft/lib-lwip .unikraft/libs/lwip
git clone https://github.com/unikraft/lib-musl .unikraft/libs/musl
git clone https://github.com/unikraft/lib-click .unikraft/libs/click
UK_DEFCONFIG=$(pwd)/.config.click-qemu-x86_64 make defconfig
make -j $(nproc)
./run-qemu-x86_64.sh

This will configure, build and run the click application.

The same can be done for AArch64, by running the commands below:

make properclean
UK_DEFCONFIG=$(pwd)/.config.click-qemu-aarch64 make defconfig
make -j $(nproc)
./run-qemu-aarch64.sh

Similar to the x86_64 build, this will start the click application. Information about every step is detailed below.

Requirements

In order to set up, configure, build and run Click on Unikraft, the following packages are required:

• build-essential / base-devel / @development-tools (the meta-package that includes make, gcc and other development-related packages)
• sudo
• flex
• bison
• git
• wget
• uuid-runtime
• qemu-system-x86
• qemu-system-arm
• qemu-kvm
• sgabios
• gcc-aarch64-linux-gnu

On Ubuntu/Debian or other apt-based distributions, run the following command to install the requirements:

sudo apt install -y --no-install-recommends \
  build-essential \
  sudo \
  gcc-aarch64-linux-gnu \
  libncurses-dev \
  libyaml-dev \
  flex \
  bison \
  git \
  wget \
  uuid-runtime \
  qemu-kvm \
  qemu-system-x86 \
  qemu-system-arm \
  sgabios

Running Click Unikraft with QEMU requires networking support. For this to work properly a specific configuration must be enabled for QEMU. Run the commands below to enable that configuration (for the network bridge to work):

sudo mkdir /etc/qemu/
echo "allow all" | sudo tee /etc/qemu/bridge.conf

Set Up

The following repositories are required for Click:

• The application repository (this repository): app-click
• The Unikraft core repository: unikraft
• Library repositories:
  • The networking stack library: lib-lwip
  • The Musl libc library: lib-musl
  • The Click library: lib-click

Follow the steps below for the setup:

1. First clone the app-click repository in the click/ directory:

   git clone https://github.com/unikraft/app-click click

   Enter the click/ directory:

   cd click/
   
   ls -F

   This will print the contents of the repository:

   .config.click-qemu-aarch64  .config.click-qemu-x86_64  fs0/  kraft.yaml  Makefile  Makefile.uk  README.md helloworld.click
   

2. While inside the click/ directory, create the .unikraft/ directory:

   mkdir .unikraft

   Enter the .unikraft/ directory:

   cd .unikraft/

3. While inside the .unikraft directory, clone the unikraft repository:

   git clone https://github.com/unikraft/unikraft unikraft

4. While inside the .unikraft/ directory, create the libs/ directory:

   mkdir libs

5. While inside the .unikraft/ directory, clone the library repositories in the libs/ directory:

   git clone https://github.com/unikraft/lib-lwip libs/lwip
   git clone https://github.com/unikraft/lib-musl libs/musl
   git clone https://github.com/unikraft/lib-click libs/click

6. Get back to the application directory:

   cd ../

   Use the tree command to inspect the contents of the .unikraft/ directory. It should print something like this:

   tree -F -L 2 .unikraft/

   The layout of the .unikraft/ directory should look something like this:

   .unikraft/
   |-- libs/
   |   `-- lwip/
   |   `-- musl/
   |   `-- click/
   `-- unikraft/
       |-- arch/
       |-- Config.uk
       |-- CONTRIBUTING.md
       |-- COPYING.md
       |-- include/
       |-- lib/
       |-- Makefile
       |-- Makefile.uk
       |-- plat/
       |-- README.md
       |-- support/
       `-- version.mk
   
   10 directories, 7 files
   

Configure

Configuring, building and running a Unikraft application depends on our choice of platform and architecture. Currently, supported platforms are QEMU (KVM), Xen and linuxu. QEMU (KVM) is known to be working, so we focus on that.

Supported architectures are x86_64 and AArch64.

Use the corresponding the configuration files (.config-...), according to your choice of platform and architecture.

QEMU x86_64

Use the .config.click-qemu-x86_64 configuration file together with make defconfig to create the configuration file:

UK_DEFCONFIG=$(pwd)/.config.click-qemu-x86_64 make defconfig

This results in the creation of the .config file:

ls .config
.config

The .config file will be used in the build step.

QEMU AArch64

Use the .config.click-qemu-aarch64 configuration file together with make defconfig to create the configuration file:

UK_DEFCONFIG=$(pwd)/.config.click-qemu-aarch64 make defconfig

Similar to the x86_64 configuration, this results in the creation of the .config file that will be used in the build step.

Build

Building uses as input the .config file from above, and results in a unikernel image as output. The unikernel output image, together with intermediary build files, are stored in the build/ directory.

Clean Up

Before starting a build on a different platform or architecture, you must clean up the build output. This may also be required in case of a new configuration.

Cleaning up is done with 3 possible commands:

• make clean: cleans all actual build output files (binary files, including the unikernel image)
• make properclean: removes the entire build/ directory
• make distclean: removes the entire build/ directory and the .config file

Typically, you would use make properclean to remove all build artifacts, but keep the configuration file.

QEMU x86_64

Building for QEMU x86_64 assumes you did the QEMU x86_64 configuration step above. Build the Unikraft Click image for QEMU x86_64 by using the command below:

make -j $(nproc)

This will print a list of files that are generated by the build system.

[...]
  LD      click_qemu-x86_64.dbg
  UKBI    click_qemu-x86_64.dbg.bootinfo
  SCSTRIP click_qemu-x86_64
  GZ      click_qemu-x86_64.gz
make[1]: Leaving directory '[...]/click/.unikraft/unikraft'

At the end of the build command, the click-x86_64 unikernel image is generated. This image is to be used in the run step.

QEMU AArch64

If you had configured and build a unikernel image for another platform or architecture (such as x86_64) before, then:

1. Do a cleanup step with make properclean.

2. Configure for QEMU AAarch64, as shown above.

3. Follow the instructions below to build for QEMU AArch64.

Building for QEMU AArch64 assumes you did the QEMU AArch64 configuration step above. Build the Unikraft Click image for QEMU AArch64 by using the same command as for x86_64:

make -j $(nproc)

This will print a list of files that are generated by the build system.

[...]
  LD      click_qemu-arm64.dbg
  UKBI    click_qemu-arm64.dbg.bootinfo
  SCSTRIP click_qemu-arm64
  GZ      click_qemu-arm64.gz
make[1]: Leaving directory '[...]/click/.unikraft/unikraft'

Similarly to x86_64, at the end of the build command, the click-arm64 unikernel image is generated. This image is to be used in the run step.

Run

The resulting image can be run with the qemu-system-* commands. In order to run the click helloworld application, you need to first set up a network bridge. All this is part of the ./run-qemu-*.sh scripts.

QEMU x86_64

To run the QEMU x86_64 build, use ./run-qemu-x86_64.sh:

./run-qemu-x86_64.sh

This will start the click helloworld application:

SeaBIOS (version 1.16.0-debian-1.16.0-5)

iPXE (https://ipxe.org) 00:03.0 CA00 PCI2.10 PnP PMM+06FCAFC0+06F0AFC0 CA00
                                                    
Powered by
o.   .o       _ _               __ _
Oo   Oo  ___ (_) | __ __  __ _ ' _) :_
oO   oO ' _ `| | |/ /  _)' _` | |_|  _)
oOo oOO| | | | |   (| | | (_) |  _) :_
 OoOoO ._, ._:_:_,\_._,  .__,_:_, \___)
      Prometheus 0.14.0~c66cdc68-custom
Received config (length 144):
define($MAC0 52:54:00:12:34:56);
/* End unikraft-provided MAC preamble */
FromDevice
  -> Print('Hello, World!')
  -> EtherMirror
  -> ToDevice;
Hello, World!:   90 | 33330000 0016fe93 a0e40183 86dd6000 00000024 00010000
Hello, World!:  130 | 33330000 00160af9 d92a3d5f 86dd6000 0000004c 0001fe80
[router_thread:200] Starting driver...

Hello, World!:   86 | 3333ffe4 0183fe93 a0e40183 86dd6000 00000020 3aff0000
Hello, World!:   90 | 33330000 0016fe93 a0e40183 86dd6000 00000024 00010000

To close the QEMU click application, use the Ctrl+a x keyboard shortcut; that is press the Ctrl and a keys at the same time and then, separately, press the x key.

QEMU AArch64

To run the AArch64 build, use ./run-qemu-aarch64.sh:

./run-qemu-aarch64.sh

Similar to running for x86_64, this will start the click helloworld application. Similarly, to close the QEMU Click instance, use the Ctrl+a x keyboard shortcut.