[9.x] Add read-only filesystem adapter decoration as a config option

composer.json

@@ -87,6 +87,7 @@
         "guzzlehttp/guzzle": "^7.2",
         "league/flysystem-aws-s3-v3": "^3.0",
         "league/flysystem-ftp": "^3.0",
+        "league/flysystem-read-only": "^3.3",
         "league/flysystem-sftp-v3": "^3.0",
         "mockery/mockery": "^1.4.4",
         "orchestra/testbench-core": "^7.1",

src/Illuminate/Filesystem/FilesystemManager.php

@@ -16,6 +16,7 @@
 use League\Flysystem\Local\LocalFilesystemAdapter as LocalAdapter;
 use League\Flysystem\PhpseclibV3\SftpAdapter;
 use League\Flysystem\PhpseclibV3\SftpConnectionProvider;
+use League\Flysystem\ReadOnly\ReadOnlyFilesystemAdapter;
 use League\Flysystem\UnixVisibility\PortableVisibilityConverter;
 use League\Flysystem\Visibility;
 
@@ -275,6 +276,10 @@ protected function formatS3Config(array $config)
      */
     protected function createFlysystem(FlysystemAdapter $adapter, array $config)
     {
+        if ($config['read-only'] ?? false === true) {
+            $adapter = new ReadOnlyFilesystemAdapter($adapter);
+        }
+
         return new Flysystem($adapter, Arr::only($config, [
             'directory_visibility',
             'disable_asserts',

tests/Filesystem/FilesystemManagerTest.php

@@ -2,11 +2,16 @@
 
 namespace Illuminate\Tests\Filesystem;
 
+use function fclose;
+use function file_put_contents;
+use function fopen;
+use function fwrite;
 use Illuminate\Contracts\Filesystem\Filesystem;
 use Illuminate\Filesystem\FilesystemManager;
 use Illuminate\Foundation\Application;
 use InvalidArgumentException;
 use PHPUnit\Framework\TestCase;
+use function unlink;
 
 class FilesystemManagerTest extends TestCase
 {
@@ -37,4 +42,37 @@ public function testCanBuildOnDemandDisk()
 
         rmdir(__DIR__.'/../../my-custom-path');
     }
+
+    public function testCanBuildReadOnlyDisks()
+    {
+        $filesystem = new FilesystemManager(new Application);
+
+        $disk = $filesystem->build([
+            'driver' => 'local',
+            'read-only' => true,
+            'root' => 'my-custom-path',
+            'url' => 'my-custom-url',
+            'visibility' => 'public',
+        ]);
+
+        file_put_contents(__DIR__.'/../../my-custom-path/path.txt', 'contents');
+
+        // read operations work
+        $this->assertEquals('contents', $disk->get('path.txt'));
+        $this->assertEquals(['path.txt'], $disk->files());
+
+        // write operations fail
+        $this->assertFalse($disk->put('path.txt', 'contents'));
+        $this->assertFalse($disk->delete('path.txt'));
+        $this->assertFalse($disk->deleteDirectory('directory'));
+        $this->assertFalse($disk->prepend('path.txt', 'data'));
+        $this->assertFalse($disk->append('path.txt', 'data'));
+        $handle = fopen('php://memory', 'rw');
+        fwrite($handle, 'content');
+        $this->assertFalse($disk->writeStream('path.txt', $handle));
+        fclose($handle);
+
+        unlink(__DIR__.'/../../my-custom-path/path.txt');
+        rmdir(__DIR__.'/../../my-custom-path');
+    }
 }