# FastAPI HTTP Server import { Tabs, TabsContent, TabsList, TabsTrigger } from "zudoku/ui/Tabs" {/* vale off */} This guide explains how to create and deploy a Python FastAPI web app. To run this example, follow these steps: 1. Install the CLI. Use the [unikraft CLI](/cli/unikraft) or the legacy [kraft CLI](https://unikraft.org/docs/cli/install). You need a [BuildKit](https://github.com/moby/buildkit) builder. The easiest way to get one is via [Docker](https://docs.docker.com/engine/install/). Alternatively, you can also directly set up and use BuildKit, see the [quick start](https://github.com/moby/buildkit#quick-start). 1. Clone the [`examples` repository](https://github.com/unikraft-cloud/examples) and `cd` into the `examples/httpserver-python3.12-fastapi-0.121.3/` directory: ```bash git clone https://github.com/unikraft-cloud/examples cd examples/httpserver-python3.12-fastapi-0.121.3/ ``` Make sure to log into Unikraft Cloud and pick a [metro](/platform/metros) close to you. This guide uses `fra` (Frankfurt, 🇩🇪): ```bash title="unikraft" unikraft login ``` ```bash title="kraft" # Set Unikraft Cloud access token export UKC_TOKEN=token # Set metro to Frankfurt, DE export UKC_METRO=fra ``` When done, invoke the following command to deploy this app on Unikraft Cloud: ```bash title="unikraft" unikraft build . --output /httpserver-python312-fastapi-01213:latest unikraft run --scale-to-zero policy=on,cooldown-time=1000 --metro fra -p 443:8080/tls+http -m 512M --image /httpserver-python312-fastapi-01213:latest ``` ```bash title="kraft" kraft cloud deploy --scale-to-zero on --scale-to-zero-cooldown 1s -p 443:8080/tls+http -M 512Mi . ``` The output shows the instance address and other details: ```ansi title="unikraft" metro: fra name: httpserver-python312-fastapi-01213-0n84f uuid: 5d7fc331-3c23-4953-b025-d152a872ea29 state: starting image: /httpserver-python312-fastapi-01213 resources: memory: 512MiB vcpus: 1 service: uuid: ced3df54-64cc-9217-3441-e0b4995319f0 name: dry-water-0oexx89g domains: - fqdn: dry-water-0oexx89g.fra.unikraft.app networks: - uuid: 66d1766f-0a03-8b62-eb1a-0adb09b07b1d private-ip: 10.0.1.69 mac: 12:b0:a1:15:7c:4a timestamps: created: just now ``` ```ansi title="kraft" [●] Deployed successfully! │ ├───────── name: httpserver-python312-fastapi-01213-0n84f ├───────── uuid: 5d7fc331-3c23-4953-b025-d152a872ea29 ├──────── metro: https://api.fra.unikraft.cloud/v1 ├──────── state: starting ├─────── domain: https://dry-water-0oexx89g.fra.unikraft.app ├──────── image: oci://unikraft.io//httpserver-python312-fastapi-01213@sha256:fb2a00dcf1cfc3ac821cbda05f82f38d66e63121344b9bc60c6a6e2f11917b98 ├─────── memory: 512 MiB ├────── service: dry-water-0oexx89g ├─ private fqdn: httpserver-python312-fastapi-01213-0n84f.internal └─── private ip: 10.0.1.69 ``` In this case, the instance name is `httpserver-python312-fastapi-01213-0n84f` and the address is `https://dry-water-0oexx89g.fra.unikraft.app`. They're different for each run. Use `curl` to query the Unikraft Cloud instance of the Python FastAPI web app server: ```bash curl https://dry-water-0oexx89g.fra.unikraft.app ``` ```text {"Hello":"World"} ``` You can list information about the instance by running: ```bash title="unikraft" unikraft instances list ``` ```bash title="kraft" kraft cloud instance list ``` ```ansi title="unikraft" METRO NAME STATE IMAGE ARGS MEMORY VCPUS FQDN CREATED fra httpserver-python312-fastapi-01213-0n84f standby /httpserver-python312-fastapi-01213 512MiB 1 dry-water-0oexx89g.fra.unikraft.app 2 minutes ago ``` ```ansi title="kraft" NAME FQDN STATE STATUS IMAGE MEMORY VCPUS ARGS BOOT TIME httpserver-python312-fastapi-01213-0n84f dry-water-0oexx89g.fra.unikraft.app standby standby oci://unikraft.io//httpserver-python312-fastapi-01213@sha25... 512 MiB 1 169.45 ms ``` When done, you can remove the instance: ```bash title="unikraft" unikraft instances remove httpserver-python312-fastapi-01213-0n84f ``` ```bash title="kraft" kraft cloud instance remove httpserver-python312-fastapi-01213-0n84f ``` ## Customize your app To customize the app, update the files in the repository, listed below: * `server.py`: the entry point for the app * `Kraftfile`: the Unikraft Cloud specification * `Dockerfile`: the Docker-specified app filesystem Lines in the `Kraftfile` have the following roles: * `spec: v0.7`: The current `Kraftfile` specification version is `0.7`. * `runtime: base-compat:latest`: The Unikraft runtime kernel to use is the latest that provides a minimal Linux-compatible environment. * `rootfs`: Build the app root filesystem. `source: ./Dockerfile` means the filesystem is built using the `Dockerfile`. `type: erofs` means the filesystem type is [EROFS](https://erofs.docs.kernel.org/). * `cmd: ["/usr/bin/python3", "-m", "uvicorn", "src.server:app", "--host", "0.0.0.0", "--port", "8080"]`: Use this as the starting command of the instance. Lines in the `Dockerfile` have the following roles: * `FROM scratch`: Build the filesystem from the [`scratch` container image](https://hub.docker.com/_/scratch/), to [create a base image](https://docs.docker.com/build/building/base-images/). The following options are available for customizing the app: * If you only update the implementation in the `server.py` source file, you don't need to make any other changes. * If you create any new source files, copy them into the app filesystem by using the `COPY` command in the `Dockerfile`. * More extensive changes may require extending the `Dockerfile` ([see `Dockerfile` syntax reference](https://docs.docker.com/engine/reference/builder/)). ## Learn more Use the `--help` option for detailed information on using Unikraft Cloud: ```bash title="unikraft" unikraft --help ``` ```bash title="kraft" kraft cloud --help ``` Or visit the [CLI Reference](/cli/unikraft) or the [legacy CLI Reference](/cli/kraft/overview). {/* vale on */}