This directory contains an example Flask 3.0 HTTP server.

To run this example, install Unikraft's companion command-line toolchain kraft, clone this repository and cd into this directory.

Use kraft to run the image and start a Unikraft instance:

kraft run --rm -p 8080:8080 --plat qemu --arch x86_64 -M 512M .

If the --plat argument is left out, it defaults to qemu. If the --arch argument is left out, it defaults to your system's CPU architecture.

Once executed, it will open port 8080 and wait for connections. To test it, you can use curl:

curl localhost:8080

You should see a "Bye, World!" message.

To list information about the Unikraft instance, use:

kraft ps

NAME             KERNEL                          ARGS            CREATED         STATUS   MEM   PORTS                   PLAT
strange_harambe  oci://unikraft.org/python:3.10  /app/server.py  11 seconds ago  running  488M  0.0.0.0:8080->8080/tcp  qemu/x86_64

The instance name is strange_harambe. To close the Unikraft instance, close the kraft process (e.g., via Ctrl+c) or run:

kraft rm strange_harambe

Note that depending on how you modify this example your instance may need more memory to run. To do so, use the kraft run's -M flag, for example:

kraft run --rm -p 8080:8080 --plat qemu --arch x86_64 -M 1024M .

Mixing invocations of kraft and sudo can lead to unexpected behavior. Read more about how to start kraft without sudo at https://unikraft.org/sudoless.

• How to run unikernels locally
• Building Dockerfile Images with BuildKit