FC + OSS 简单图床

<?php

use OSS\OssClient;
use RingCentral\Psr7\Response;

// 获取存储桶名称
$bucket = getenv('oss_bucket');
// 获取存储桶地域
$region = getenv('oss_region');
// OSS 全局存储
$oss = null;

function initializer($context) {
    global $oss, $region;

    if(is_null($oss)) {
        // 实例化 OSS
        // $oss = new OssClient(
        //     'yourAccessKeyId',
        //     'yourAccessKeySecret',
        //     'https://oss-' . $region . '.aliyuncs.com'
        // );
        $oss = new OssClient(
            $context['credentials']['accessKeyId'],
            $context['credentials']['accessKeySecret'],
            'https://oss-' . $region . '.aliyuncs.com',
            false,
            $context['credentials']['securityToken']
        );
    }
}

function handler($request, $context): Response{
    global $oss, $bucket;

    // 如果是 GET 的话直接返回前端文件，这个需要自定义域名支持。
    if($request->getMethod() === 'GET') {
        return new Response(
            200,
            [
                'Content-type' => 'text/html; charset=utf-8',
            ],
            file_get_contents(__DIR__ . '/index.html')
        );
    }

    // 支持的类型和对应的后缀名
    $types = [
        'image/jpeg'    => 'jpg',
        'image/png'     => 'png',
        'image/gif'     => 'gif',
        'image/webp'    => 'webp',
    ];

    // 获取 param 参数
    $param = $request->getQueryParams();

    if(!isset($param['type'])) {
        return error('参数错误');
    }

    $type = $param['type'];

    if(!isset($types[$type])) {
        return error('不支持此格式');
    }

    // 生成文件路径
    $filepath = generate_path($types[$type]);

    // 获取签名
    $sign = $oss->signUrl($bucket, $filepath, 10 * 60, 'PUT');

    return result([
        'sign'  => $sign,
        'url'   => 'https://' . getenv('cdn_domain') . '/' . $filepath,
    ]);
}

/*
 * 生成文件路径
 * 
 * @param string $suffix 文件后缀
 * @return string
 */
function generate_path($suffix) {
    global $oss, $bucket;

    $path = date('Ymd/') . str_rand() . '.' . $suffix;

    $exist = $oss->doesObjectExist($bucket, $path);

    if($exist) {
        return generate_path($suffix);
    }

    return $path;
}

/*
 * 随机字符串
 * 
 * @param int $length 长度
 * @return string
 */
function str_rand(int $length = 6){
    $length = ($length < 4) ? 4 : $length;
    return bin2hex(random_bytes(($length-($length%2))/2));
}

/**
 * 返回成功
 *
 * @param array  $data  数据
 * @return RingCentral\Psr7\Response
 */
function result($data = []): Response {
    return new Response(
        200,
        [],
        json_encode([
            'code'  => 1,
            'data'  => $data,
        ])
    );
}

/**
 * 返回错误
 *
 * @param string  $msg  错误信息
 * @return RingCentral\Psr7\Response
 */
function error($msg): Response {
    return new Response(
        200,
        [],
        json_encode([
            'code'  => 0,
            'msg'   => $msg,
        ])
    );
}