$ composer create-project --prefer-dist laravel/lumen lumen-firebase-storage

$ composer require league/flysystem superbalist/laravel-google-cloud-storage

$app->register(Superbalist\LaravelGoogleCloudStorage\GoogleCloudStorageServiceProvider::class);

<?php
return [
    /*
    |--------------------------------------------------------------------------
    | Default Filesystem Disk
    |--------------------------------------------------------------------------
    |
    | Here you may specify the default filesystem disk that should be used
    | by the framework. The "local" disk, as well as a variety of cloud
    | based disks are available to your application. Just store away!
    |
    */
    'default' => env('FILESYSTEM_DRIVER', 'local'),
    /*
    |--------------------------------------------------------------------------
    | Default Cloud Filesystem Disk
    |--------------------------------------------------------------------------
    |
    | Many applications store files both locally and in the cloud. For this
    | reason, you may specify a default "cloud" driver here. This driver
    | will be bound as the Cloud disk implementation in the container.
    |
    */
    'cloud' => env('FILESYSTEM_CLOUD', 's3'),
    /*
    |--------------------------------------------------------------------------
    | Filesystem Disks
    |--------------------------------------------------------------------------
    |
    | Here you may configure as many filesystem "disks" as you wish, and you
    | may even configure multiple disks of the same driver. Defaults have
    | been setup for each driver as an example of the required options.
    |
    | Supported Drivers: "local", "ftp", "sftp", "s3", "rackspace"
    |
    */
    'disks' => [
        'local' => [
            'driver' => 'local',
            'root' => storage_path('app'),
        ],
        'public' => [
            'driver' => 'local',
            'root' => storage_path('app/public'),
            'url' => env('APP_URL').'/storage',
            'visibility' => 'public',
        ],
        'gcs' => [
            'driver' => 'gcs',
            'project_id' => env('GOOGLE_CLOUD_PROJECT_ID', 'your-project-id'),
            'key_file' => env('GOOGLE_CLOUD_KEY_FILE', null),
            'bucket' => env('GOOGLE_CLOUD_STORAGE_BUCKET', 'your-bucket'),
            'path_prefix' => env('GOOGLE_CLOUD_STORAGE_PATH_PREFIX', null),
            'storage_api_uri' => env('GOOGLE_CLOUD_STORAGE_API_URI', null),
            'visibility' => 'public',
        ],
    ],
];

GOOGLE_CLOUD_PROJECT_ID=
GOOGLE_CLOUD_KEY_FILE=
GOOGLE_CLOUD_STORAGE_BUCKET=

GOOGLE_CLOUD_PROJECT_ID=lumen-firebase-storage
GOOGLE_CLOUD_KEY_FILE=lumen-firebase-storage-6f23d79dad93.json
GOOGLE_CLOUD_STORAGE_BUCKET=lumen-firebase-storage.appspot.com

<?php

use Illuminate\Http\Request;
use Illuminate\Support\Facades\Storage;

/*
|--------------------------------------------------------------------------
| Application Routes
|--------------------------------------------------------------------------
|
| Here is where you can register all of the routes for an application.
| It is a breeze. Simply tell Lumen the URIs it should respond to
| and give it the Closure to call when that URI is requested.
|
*/

$router->get('/', function () use ($router) {
    return $router->app->version();
});

// Upload gambar ke Firebase Storage
$router->post('/images', function (Request $request) use ($router) {
    $this->validate($request, [
        'image' => 'required|image',
    ]);
    $file = $request->file('image');
    $name = time() . '-' . $file->getClientOriginalName();
    $filePath = 'images/' . $name;
    Storage::disk('gcs')->put($filePath, file_get_contents($file));
    return response()->json([
        'message' => 'Gambar berhasil diupload'
    ]);
});

// Menampilkan semua gambar
$router->get('/images', function () use ($router) {
    $images = [];
    $files = Storage::disk('gcs')->files('images');
    foreach ($files as $file) {
        $images[] = [
            'name' => str_replace('images/', '', $file),
            'src'  => Storage::disk('gcs')->url($file),
        ];
    }
    return response()->json($images);
});

// Menghapus gambar
$router->post('/delete-images', function (Request $request) use ($router) {
    $this->validate($request, [
        'image' => 'required',
    ]);
    $image = $request->input('image');
    Storage::disk('gcs')->delete('images/' . $image);
    return response()->json([
        'message' => 'Gambar berhasil dihapus '
    ]);
});

$ php -S localhost:3000 -t public