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:

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

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

# Set KraftCloud access token
export KRAFTCLOUD_TOKEN=token
# Set metro to Frankfurt, DE
export KRAFTCLOUD_METRO=fra0

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

kraft cloud deploy -p 443:8080 .

The output shows the instance URL and other details:

[●] 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 group: 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 KraftCloud instance of the PHP-based HTTP web server:

curl https://aged-fire-rh0oi0tj.fra0.kraft.host

Hello, World!

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

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  razvan.unikraft.io/http-php82@sha256:dccaac05398267376...  256 MiB  /usr/local/bin/php /usr/src/server.php  32801us

When done, you can remove the instance:

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 KraftCloud specification
• Dockerfile: the Docker-specified application filesystem

server.php

#!/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);
?>

php.ini

[PHP]

extension=sockets

Kraftfile

spec: v0.6

runtime: php:8.2

rootfs: ./Dockerfile

cmd: ["/usr/local/bin/php", "/usr/src/server.php"]

Dockerfile

FROM scratch

# PHP configuration
COPY ./php.ini /usr/local/etc/php/php.ini

# Simple PHP HTTP server
COPY ./server.php /usr/src/server.php

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 KraftCloud:

kraft cloud --help

Or visit the CLI Reference.