org2changelog.php

<?php

$org = isset($argv[1]) ? $argv[1] : 'leproxy';

function fetch($url) {
    fwrite(STDERR, 'Fetch ' . $url . PHP_EOL);
    // optionally pass GITHUB_TOKEN env variable (create one on https://github.com/settings/tokens first)
    $data = file_get_contents($url, false, stream_context_create(array('http' => array('header' => array(
        'User-Agent: github-releases v1',
        'Authorization: token ' . getenv('GITHUB_TOKEN')
    )))));
    if ($data === false) {
        exit(1);
    }

    $all = json_decode($data, true);
    if ($all === null) {
        exit(1);
    }

    // http://php.net/manual/en/reserved.variables.httpresponseheader.php
    foreach ($http_response_header ?? [] as $line) {
        if (preg_match('/link: <([^>]+)>; rel="next"/i', $line, $m)) {
            return array_merge($all, fetch($m[1]));
        }
    }

    return $all;
}

$repos = fetch('https://api.github.com/orgs/' . $org . '/repos');

$releases = array();
foreach ($repos as $repo) {
    $some = fetch('https://api.github.com/repos/' . $repo['full_name'] . '/releases?per_page=100');
    foreach ($some as $one) {
        $time = (int)(new \DateTime($one['created_at']))->format('U');

        // sort by time (latest first) and otherwise project name
        $releases[(PHP_INT_MAX - $time) . '-' . $repo['full_name']] = array('project' => $repo) + $one;
    }
}
ksort($releases, SORT_NATURAL);

echo '# Changelog' . PHP_EOL;

foreach ($releases as $release) {
    $version = ltrim($release['tag_name'], 'v');
    $date = (new DateTime($release['created_at']))->format('Y-m-d');
    $body = preg_replace('/\r?\n/', PHP_EOL, rtrim($release['body']));

    //echo PHP_EOL . '## [' . $version . '] - ' . $date . PHP_EOL . PHP_EOL;
    echo PHP_EOL . '## ' . $release['project']['full_name'] . ' ' . $version . ' (' . $date . ')' . PHP_EOL . PHP_EOL;
    echo $body . PHP_EOL;
}