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Unikraft Cloud

Run a PHP app

In this guide we create and deploy a simple PHP-based HTTP web server. 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-php8.2/ directory:

Terminal window
git clone https://github.com/kraftcloud/examples
cd examples/http-php8.2/

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

Terminal window
# Set Unikraft Cloud access token
export UKC_TOKEN=token
# Set metro to Frankfurt, DE
export UKC_METRO=fra0

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

Terminal window
kraft cloud deploy -p 443:8080 .

The output shows the instance URL and other details:

Terminal window
[●] Deployed successfully!
 │
 ├────────── name: http-php82-g00si
 ├────────── uuid: 033b2f4b-72ff-414d-b0de-63571477c657
 ├───────── state: running
 ├─────────── url: https://aged-fire-rh0oi0tj.fra0.kraft.host
 ├───────── image: http-php82@sha256:dccaac053982673765b8f00497a9736c31458ab23ad59a550b09aa8dedfabb34
 ├───── boot time: 32.80 ms
 ├──────── memory: 128 MiB
 ├─────── service: aged-fire-rh0oi0tj
 ├── private fqdn: http-php82-g00si.internal
 ├──── private ip: 172.16.3.3
 └────────── args: /usr/local/bin/php /usr/src/server.php

In this case, the instance name is http-php82-g00si and the URL is https://aged-fire-rh0oi0tj.fra0.kraft.host. They are different for each run.

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

Terminal window
curl https://aged-fire-rh0oi0tj.fra0.kraft.host
Hello, World!

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

Terminal window
kraft cloud instance list
NAME              FQDN                                STATE    CREATED AT      IMAGE                                   MEMORY   ARGS                                    BOOT TIME
http-php82-g00si  aged-fire-rh0oi0tj.fra0.kraft.host  running  50 seconds ago  http-php82@sha256:dccaac05398267376...  256 MiB  /usr/local/bin/php /usr/src/server.php  32801us

When done, you can remove the instance:

Terminal window
kraft cloud instance remove http-php82-g00si

Customize your Application

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

  • server.php: the actual PHP HTTP server
  • php.ini: the PHP configuration
  • Kraftfile: the Unikraft Cloud specification
  • Dockerfile: the Docker-specified application filesystem
#!/usr/local/bin/php -q
<?php
error_reporting(E_ALL);


/* Allow the script to hang around waiting for connections. */
set_time_limit(0);


/* Turn on implicit output flushing so we see what we're getting
 * as it comes in. */
ob_implicit_flush();


$address = '0.0.0.0';
$port = 8080;


if (($sock = socket_create(AF_INET, SOCK_STREAM, SOL_TCP)) === false) {
    echo "socket_create() failed: reason: " . socket_strerror(socket_last_error()) . "\n";
}


if (socket_bind($sock, $address, $port) === false) {
    echo "socket_bind() failed: reason: " . socket_strerror(socket_last_error($sock)) . "\n";
}


if (socket_listen($sock, 5) === false) {
    echo "socket_listen() failed: reason: " . socket_strerror(socket_last_error($sock)) . "\n";
}


do {
    if (($msgsock = socket_accept($sock)) === false) {
        echo "socket_accept() failed: reason: " . socket_strerror(socket_last_error($sock)) . "\n";
        break;
    }
    /* Send instructions. */
    $msg = "HTTP/1.1 200 OK\r\n" .
        "Content-Type: text/html\r\n" .
        "Content-Length: 14\r\n" .
        "Connection: close\r\n" .
        "\r\n" .
        "Hello, World!\n";
    socket_write($msgsock, $msg, strlen($msg));


    socket_close($msgsock);
} while (true);


socket_close($sock);
?>

The following options are available for customizing the application:

  • If only updating the implementation in the server.php 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 extension are required, that may require the update the of the php.ini file.

  • If a new PHP source files is added, update the cmd line in the Kraftfile and replace server.php to run that file when creating the instance.

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

Learn More

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

Terminal window
kraft cloud --help

Or visit the CLI Reference.