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Guides

Elixir HTTP Server

This guide explains how to create and deploy a simple Elixir-based HTTP web server. To run this example, follow these steps:

1. Install the CLI. Use the unikraft CLI or the legacy kraft CLI. You need a BuildKit builder. The easiest way to get one is via Docker. Alternatively, you can also directly set up and use BuildKit, see the quick start.

   The unikraft CLI is the current standard, while kraft is the legacy version. Choose one of the CLIs below and only run the commands associated with it for the rest of this guide.

2. Clone the examples repository and cd into the examples/httpserver-elixir1.16/ directory:

   Code
   git clone https://github.com/unikraft-cloud/examples
   cd examples/httpserver-elixir1.16/

Make sure to log into Unikraft Cloud and pick a metro close to you. This guide uses fra (Frankfurt, 🇩🇪):

When done, invoke the following command to deploy this app on Unikraft Cloud:

The output shows the instance address and other details:

In this case, the instance name is httpserver-elixir116-qo9k3 and the address is https://small-water-tl8lr8am.fra.unikraft.app. They're different for each run.

Use curl to query the Unikraft Cloud instance of the Elixir-based HTTP web server:

Code
curl https://small-water-tl8lr8am.fra.unikraft.app

Code
Hello, World!

You can list information about the instance by running:

When done, you can remove the instance:

Customize your app

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

• lib/, mix.exs: the actual Elixir HTTP server implementation
• Kraftfile: the Unikraft Cloud specification
• Dockerfile: the Docker-specified app filesystem

The following options are available for customizing the app:

• If you only update the implementation in the lib/server.ex or lib/server/app.ex source code files, no other changes apply. If you add new source files in the lib/ directory, 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).

The following commands generate the current source code files and configuration file (mix.exs):

Code
mix new --app server . --sup

Use a similar command to create a new app. Then update it and deploy it on Unikraft Cloud using the above instructions.

Learn more

Use the --help option for detailed information on using Unikraft Cloud:

Or visit the CLI Reference or the legacy CLI Reference.