No way to access an existing S3 bucket!

[mirkoscotti]

Creating a new S3 bucket through the newFileSystem API works properly. See the example below:

public static void main(String[] args) throws IOException
{
	System.setProperty("aws.accessKeyId", "MY-ACCESS-KEY");
	System.setProperty("aws.secretAccessKey", "MY-SECRET-KEY");
	System.setProperty("aws.region", Region.EU_NORTH_1.id());
	var hostName = InetAddress.getLocalHost().getHostName().toLowerCase();
	var uri = URI.create("s3://%s-test-bucket/".formatted(hostName));
	var classLoader = Thread.currentThread().getContextClassLoader();
	try (var fileSystem = FileSystems.newFileSystem(uri, Map.<String, Object>of(), classLoader))
	{
		fileSystem.getRootDirectories().forEach(System.out::println);
	}
}

Ultimately, I can find the new bucket nbk325-test-bucket successfully created. But if I run the following code (simply replacing the newFileSystem just created before by getFileSystem to access that bucket):

public static void main(String[] args) throws IOException
{
	System.setProperty("aws.accessKeyId", "MY-ACCESS-KEY");
	System.setProperty("aws.secretAccessKey", "MY-SECRET-KEY");
	System.setProperty("aws.region", Region.EU_NORTH_1.id());
	var hostName = InetAddress.getLocalHost().getHostName().toLowerCase();
	var uri = URI.create("s3://%s-test-bucket/".formatted(hostName));
	try (var fileSystem = FileSystems.getFileSystem(uri))
	{
		fileSystem.getRootDirectories().forEach(System.out::println);
	}
}

my program crashes with this trace:

Exception in thread "main" java.nio.file.FileSystemNotFoundException: file system not found for 'nbk325-test-bucket'
	at software.amazon.nio.spi.s3.S3FileSystemProvider.lambda$getFileSystem$6(S3FileSystemProvider.java:777)
	at java.base/java.util.HashMap.computeIfAbsent(HashMap.java:1228)
	at software.amazon.nio.spi.s3.S3FileSystemProvider.getFileSystem(S3FileSystemProvider.java:775)
	at software.amazon.nio.spi.s3.S3FileSystemProvider.getFileSystem(S3FileSystemProvider.java:219)
	at java.base/java.nio.file.FileSystems.getFileSystem(FileSystems.java:235)
	at test.Main.main(Main.java:32)

The reason for this failure is that the getFileSystem method in S3FileSystemProvider expects to find the file system already cached, but it is not because at startup the in-memory FS_CACHE is of course empty!!

@Override
public FileSystem getFileSystem(URI uri) {
    return getFileSystem(uri, false);
}
...
S3FileSystem getFileSystem(URI uri, boolean create) {
    var info = fileSystemInfo(uri);
    return FS_CACHE.computeIfAbsent(info.key(), (key) -> {  
        if (!create) { <== HERE IS THE CRASH!!
            throw new FileSystemNotFoundException("file system not found for '" + info.key() + "'");
        }

        var config = new S3NioSpiConfiguration().withEndpoint(info.endpoint()).withBucketName(info.bucket());
        if (info.accessKey() != null) {
            config.withCredentials(info.accessKey(), info.accessSecret());
        }
        return new S3FileSystem(this, config);
    });
}

In my opinion, the create flag does not make sense. I would suggest removing it and converting the code above to the following which works very well:

@Override
public FileSystem getFileSystem(URI uri) {
    var info = fileSystemInfo(uri);
    return FS_CACHE.computeIfAbsent(info.key(), (key) -> {  
        var config = new S3NioSpiConfiguration().withEndpoint(info.endpoint()).withBucketName(info.bucket());
        if (info.accessKey() != null) {
            config.withCredentials(info.accessKey(), info.accessSecret());
        }
        return new S3FileSystem(this, config);
    });
}

[markjschreiber]

Agreed. I don't think there is a need for the create test. I will try to make this fix in the next week or so. If you would like to contribute a PR with this fix I can review it sooner.

[markjschreiber]

closed by #463