User’s Guide

To begin using Unikraft you’ll need to have gcc, make and git installed. First clone the Unikraft main repo:

git clone http://xenbits.xen.org/git-http/unikraft/unikraft.git

If you’ll be using Unikraft external libraries, this would be the time to clone those too. You can see a list of available libraries at http://xenbits.xen.org/gitweb/?a=project_list;pf=unikraft/libs . Each external library has its own separate repo, so you’ll need to clone each one separately.

Finally, you’ll need to create a Unikraft application. To get quickly started, the easiest is to clone the hello world app (once again, each Unikraft app has its own repo):

git clone http://xenbits.xen.org/git-http/unikraft/apps/helloworld.git

Now edit the Makefile in the app directory. In particular, set the UK_ROOT and UK_LIBS variables to point to the directories where you cloned the repos above. For instance, assuming the following directory structure

├── unikraft
├── unikraft-apps
│  ├── helloworld
│  ├── app1
│  ├── app2
└── unikraft-libs
   ├── lib1
   ├── lib2
   └── libN

where your app is located at unikraft-apps/helloworld, you would set those variables as follows:

UK_ROOT ?= $(PWD)/../../unikraft
UK_LIBS ?= $(PWD)/../../unikraft-libs

Finally, if your app will be using external libraries, set the LIBS variable to reflect this. For instance :

LIBS := $(UK_LIBS)/lib1:$(UK_LIBS)/lib2:$(UK_LIBS)/libN

Note that the list has to be colon-separated.

With all of this in place, we’re now ready to start configuring the application image via Unikraft’s menu. To access it, from within the app’s directory simply type

make menuconfig

The menu system is fairly self-explanatory and will be familiar to anyone who has configured a Linux kernel before. Select the options you want, the libraries you’ll like to include and don’t forget to select at least one platform (e.g., KVM, Xen or Linux user-space – the latter is quite useful for quick testing and debugging).

Finally, quit the menu while saving the configuration changes you’ve made and build your application by just typing make. Unikraft will then build each library in turn as well as the source files for your application, producing one image in the ./build directory for each platform type you selected.

Running the image will depend on which platform you targeted. For Linux user-space, for instance, the image is just a standard ELF, so you can simply run it with

./build/helloworld_linuxu-x86_64

And that’s it! We’ll be posting further Unikraft application repos at

http://xenbits.xen.org/gitweb/?a=project_list;pf=unikraft/apps

For more information regarding porting and developing apps (and libraries) in Unikraft please read the developer’s guide.