Skip to content

Run a Rust Tokio app

This example uses Tokio, a popular Rust asynchronous runtime. To run this example, follow these steps:

  1. Install the kraft CLI tool and a container runtime engine, e.g. Docker.

  2. Clone the examples repository and cd into the examples/http-rust1.75-tokio/ directory:

Terminal window
git clone
cd examples/http-rust1.75-tokio/

Make sure to log into KraftCloud by setting your token and a metro close to you. We use fra0 (Frankfurt, 🇩🇪) in this guide:

Terminal window
# Set KraftCloud access token
# Set metro to Frankfurt, DE

When done, invoke the following command to deploy this application on KraftCloud:

Terminal window
kraft cloud deploy -p 443:8080 .

The output shows the instance URL and other details:

Terminal window
[] Deployed successfully!
────────── name: http-rust175-tokio-6gxsp
────────── uuid: d5719f64-0653-42d7-b2de-aa6dee0ce467
───────── state: running
─────────── url:
───────── image: http-rust175-tokio@sha256:0ce75912711aa2329232a2ca6c3ccb7a244b6d546fafc081f815c2fde8224856
───── boot time: 21.41 ms
──────── memory: 128 Mi
service group: empty-dawn-3coedrce
── private fqdn: http-rust175-tokio-6gxsp.internal
──── private ip:
────────── args: /server

In this case, the instance name is http-rust175-tokio-6gxsp and the URL is ` They are different for each run.

Use curl to query the KraftCloud instance of the Tokio-based HTTP web server:

Terminal window
Hello, World!

At any point in time, you can list information about the instance:

Terminal window
kraft cloud instance list
http-rust175-tokio-6gxsp empty-dawn-3coedrce.fra0... running 1 minute ago http-rust175-tokio@sha256:0ce75912711aa2329232a2ca6c3ccb7a244b6d546fafc08... 128 MiB /server 21412us

When done, you can remove the instance:

Terminal window
kraft cloud instance remove http-rust175-tokio-6gxsp

Customize your Application

To customize the application, update the files in the repository, listed below:

  • src/ the actual server
  • Cargo.toml: the Cargo package manager configuration file
  • Kraftfile: the KraftCloud specification
  • Dockerfile: the Docker-specified application filesystem
spec: v0.6
runtime: base:latest
rootfs: ./Dockerfile
cmd: ["/server"]

The following options are available for customizing the application:

  • If only updating the implementation in the src/ source file, no other change is required.

  • If new files are added, these have to be copied in the application filesystem, using the COPY command in the Dockerfile. If new Rust source code files are added, be sure to configure required dependencies in the Cargo.toml file.

  • If a new executable is built, update the cmd line in the Kraftfile and replace /server with the path to the new executable.

  • More extensive changes may require expanding the Dockerfile with additional Dockerfile commands.

Learn More

Use the --help option for detailed information on using KraftCloud:

Terminal window
kraft cloud --help

Or visit the CLI Reference.