Guides

Perl

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 kraft CLI tool and a container runtime engine, for example Docker.

2. Clone the examples repository and cd into the examples/http-perl5.38/ directory:

Code(bash)
 
git clone https://github.com/kraftcloud/examples
cd examples/http-perl5.38/

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

Code(bash)
 
# 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:

Code(bash)
 
kraft cloud deploy -p 443:8080 -M 512 .

The output shows the instance address and other details:

Code(ansi)
 
[●] Deployed successfully!
 │
 ├────────── name: http-perl538-1p4ml
 ├────────── uuid: eabb0080-0065-40ff-81a8-f790f1b218ee
 ├───────── state: running
 ├─────────── url: https://cold-brook-ba71jc16.fra.unikraft.app
 ├───────── image: http-perl538@sha256:8c2c1f536b349c24e04ab4fec508b69f7f2349302d42a02855318ee55c12e37c
 ├───── boot time: 64.56 ms
 ├──────── memory: 512 MiB
 ├─────── service: cold-brook-ba71jc16
 ├── private fqdn: http-perl538-1p4ml.internal
 ├──── private ip: 172.16.3.3
 └────────── args: /usr/bin/perl /usr/src/server.pl

In this case, the instance name is http-perl538-1p4ml and the address is https://cold-brook-ba71jc16.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(bash)
 
curl https://cold-brook-ba71jc16.fra.unikraft.app

Code(text)
 
Hello, World!

You can list information about the instance by running:

Code(bash)
 
kraft cloud instance list

Code(text)
 
NAME                FQDN                                 STATE    CREATED AT      IMAGE                                  MEMORY   ARGS                              BOOT TIME
http-perl538-1p4ml  cold-brook-ba71jc16.fra.unikraft.app  stopped  37 seconds ago  http-perl538@sha256:8c2c1f536b349c...  512 MiB  /usr/bin/perl /usr/src/server.pl  64556us

When done, you can remove the instance:

Code(bash)
 
kraft cloud instance remove http-perl538-1p4ml

Customize your app

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

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

Code(bash)
 
kraft cloud --help

Or visit the CLI Reference.