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Guides

Perl HTTP Server

This guide explains how to create and deploy a simple Perl-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-perl5.42/ directory:

   Code
   git clone https://github.com/unikraft-cloud/examples
   cd examples/httpserver-perl5.42/

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-perl542-xue8j and the address is https://fragrant-water-wau08gaw.fra.unikraft.app. They're different for each run.

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

Code
curl https://fragrant-water-wau08gaw.fra.unikraft.app

Code
Hello, World!

You can list information about the instance by running:

When you list your instances, you might notice they show as standby. This is normal behavior and means the instance is using Unikraft Cloud's scale-to-zero feature that saves resources when there is no traffic. To check your instance is working, open two terminals and use these commands to watch the status:

It switches to "running" then back to "standby."

When done, you can remove the instance:

Customize your app

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

• server.pl: the actual Perl 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 server.pl 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).

Learn more

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

Or visit the CLI Reference or the legacy CLI Reference.