Getting started with Cro

Here's a list of things to do to get Cro running on your machine.

Install Raku

Cro services are written in Raku; if you have not yet installed a Raku compiler, see these instructions.

Install Cro

Install Cro from the command line using zef:

zef install --/test cro

This includes the cro development tool, as well as the Cro core, HTTP, and web sockets libraries.

Write a Cro service

Copy the following code to a file called hello.p6:

use Cro::HTTP::Router;
use Cro::HTTP::Server;

my $application = route {
    get -> {
        content 'text/html', 'Hello Cro!';
    }
}

my Cro::Service $service = Cro::HTTP::Server.new:
    :host<localhost>, :port<10000>, :$application;

$service.start;

react whenever signal(SIGINT) {
    $service.stop;
    exit;
}

Run the Cro service

To start the service, just run the script from the command line:

raku hello.p6

Check that the service runs ok

There should now be a page saying 'Hello Cro!' at http://localhost:10000

Congratulations, you have successfully installed Cro!

Extra credit: use the cro development tool

The cro stub command generates stub services for you, to get started more quickly and with better defaults. Here we use it to create a simple HTTP service, with ID hello and in the hello directory:

cro stub http hello hello

The cro run command will start your service (and automatically restart the service if you change a file):

cro run

You can change the service by editing files in the hello/ subdirectory. The HTTP routes, for example, are in hello/lib/Routes.rakumod.

What next?

• Learn about routing URLs to handlers, working with query strings and request bodies, and producing responses using Cro::HTTP::Router

• Learn about using templates to produce responses using Cro::WebApp::Template

• Learn about sessions and authentication

• Learn about writing WebSocket handlers using Cro::HTTP::Router::WebSocket

• Learn more about the cro development tool and the associated .cro.yml file

• Learn how to structure larger services