path: root/tvix/castore/src/blobservice/from_addr.rs

use url::Url;

use crate::{proto::blob_service_client::BlobServiceClient, Error};

use super::{
    BlobService, GRPCBlobService, MemoryBlobService, ObjectStoreBlobService,
    SimpleFilesystemBlobService, SledBlobService,
};

/// Constructs a new instance of a [BlobService] from an URI.
///
/// The following schemes are supported by the following services:
/// - `memory://` ([MemoryBlobService])
/// - `sled://` ([SledBlobService])
/// - `grpc+*://` ([GRPCBlobService])
/// - `simplefs://` ([SimpleFilesystemBlobService])
///
/// See their `from_url` methods for more details about their syntax.
pub async fn from_addr(uri: &str) -> Result<Box<dyn BlobService>, crate::Error> {
    let url = Url::parse(uri)
        .map_err(|e| crate::Error::StorageError(format!("unable to parse url: {}", e)))?;

    let blob_service: Box<dyn BlobService> = match url.scheme() {
        "memory" => {
            // memory doesn't support host or path in the URL.
            if url.has_host() || !url.path().is_empty() {
                return Err(Error::StorageError("invalid url".to_string()));
            }
            Box::<MemoryBlobService>::default()
        }
        "sled" => {
            // sled doesn't support host, and a path can be provided (otherwise
            // it'll live in memory only).
            if url.has_host() {
                return Err(Error::StorageError("no host allowed".to_string()));
            }

            if url.path() == "/" {
                return Err(Error::StorageError(
                    "cowardly refusing to open / with sled".to_string(),
                ));
            }

            // TODO: expose other parameters as URL parameters?

            Box::new(if url.path().is_empty() {
                SledBlobService::new_temporary().map_err(|e| Error::StorageError(e.to_string()))?
            } else {
                SledBlobService::new(url.path()).map_err(|e| Error::StorageError(e.to_string()))?
            })
        }
        scheme if scheme.starts_with("grpc+") => {
            // schemes starting with grpc+ go to the GRPCPathInfoService.
            //   That's normally grpc+unix for unix sockets, and grpc+http(s) for the HTTP counterparts.
            // - In the case of unix sockets, there must be a path, but may not be a host.
            // - In the case of non-unix sockets, there must be a host, but no path.
            // Constructing the channel is handled by tvix_castore::channel::from_url.
            let client = BlobServiceClient::new(crate::tonic::channel_from_url(&url).await?);
            Box::new(GRPCBlobService::from_client(client))
        }
        "simplefs" => {
            if url.path().is_empty() {
                return Err(Error::StorageError("Invalid filesystem path".to_string()));
            }

            Box::new(SimpleFilesystemBlobService::new(url.path().into()).await?)
        }
        scheme if scheme.starts_with("objectstore+") => {
            // We need to convert the URL to string, strip the prefix there, and then
            // parse it back as url, as Url::set_scheme() rejects some of the transitions we want to do.
            let trimmed_url = {
                let s = url.to_string();
                Url::parse(s.strip_prefix("objectstore+").unwrap()).unwrap()
            };
            Box::new(
                ObjectStoreBlobService::parse_url(&trimmed_url)
                    .map_err(|e| Error::StorageError(e.to_string()))?,
            )
        }
        scheme => {
            return Err(crate::Error::StorageError(format!(
                "unknown scheme: {}",
                scheme
            )))
        }
    };

    Ok(blob_service)
}

#[cfg(test)]
mod tests {
    use super::from_addr;
    use lazy_static::lazy_static;
    use tempfile::TempDir;
    use test_case::test_case;

    lazy_static! {
        static ref TMPDIR_SLED_1: TempDir = TempDir::new().unwrap();
        static ref TMPDIR_SLED_2: TempDir = TempDir::new().unwrap();
    }

    /// This uses an unsupported scheme.
    #[test_case("http://foo.example/test", false; "unsupported scheme")]
    /// This configures sled in temporary mode.
    #[test_case("sled://", true; "sled valid temporary")]
    /// This configures sled with /, which should fail.
    #[test_case("sled:///", false; "sled invalid root")]
    /// This configures sled with a host, not path, which should fail.
    #[test_case("sled://foo.example", false; "sled invalid host")]
    /// This configures sled with a valid path path, which should succeed.
    #[test_case(&format!("sled://{}", &TMPDIR_SLED_1.path().to_str().unwrap()), true; "sled valid path")]
    /// This configures sled with a host, and a valid path path, which should fail.
    #[test_case(&format!("sled://foo.example{}", &TMPDIR_SLED_2.path().to_str().unwrap()), false; "sled invalid host with valid path")]
    /// This correctly sets the scheme, and doesn't set a path.
    #[test_case("memory://", true; "memory valid")]
    /// This sets a memory url host to `foo`
    #[test_case("memory://foo", false; "memory invalid host")]
    /// This sets a memory url path to "/", which is invalid.
    #[test_case("memory:///", false; "memory invalid root path")]
    /// This sets a memory url path to "/foo", which is invalid.
    #[test_case("memory:///foo", false; "memory invalid root path foo")]
    /// Correct scheme to connect to a unix socket.
    #[test_case("grpc+unix:///path/to/somewhere", true; "grpc valid unix socket")]
    /// Correct scheme for unix socket, but setting a host too, which is invalid.
    #[test_case("grpc+unix://host.example/path/to/somewhere", false; "grpc invalid unix socket and host")]
    /// Correct scheme to connect to localhost, with port 12345
    #[test_case("grpc+http://[::1]:12345", true; "grpc valid IPv6 localhost port 12345")]
    /// Correct scheme to connect to localhost over http, without specifying a port.
    #[test_case("grpc+http://localhost", true; "grpc valid http host without port")]
    /// Correct scheme to connect to localhost over http, without specifying a port.
    #[test_case("grpc+https://localhost", true; "grpc valid https host without port")]
    /// Correct scheme to connect to localhost over http, but with additional path, which is invalid.
    #[test_case("grpc+http://localhost/some-path", false; "grpc invalid has path")]
    /// An example for object store (InMemory)
    #[test_case("objectstore+memory:///", true; "objectstore valid memory url")]
    /// An example for object store (LocalFileSystem)
    #[test_case("objectstore+file:///foo/bar", true; "objectstore valid file url")]
    // An example for object store (HTTP / WebDAV)
    #[test_case("objectstore+https://localhost:8080/some-path", true; "objectstore valid http url")]
    #[tokio::test]
    async fn test_from_addr_tokio(uri_str: &str, exp_succeed: bool) {
        if exp_succeed {
            from_addr(uri_str).await.expect("should succeed");
        } else {
            assert!(from_addr(uri_str).await.is_err(), "should fail");
        }
    }

    #[cfg(feature = "cloud")]
    /// An example for object store (S3)
    #[test_case("objectstore+s3://bucket/path", true; "objectstore valid s3 url")]
    /// An example for object store (GCS)
    #[test_case("objectstore+gs://bucket/path", true; "objectstore valid gcs url")]
    #[tokio::test]
    async fn test_from_addr_tokio_cloud(uri_str: &str, exp_succeed: bool) {
        if exp_succeed {
            from_addr(uri_str).await.expect("should succeed");
        } else {
            assert!(from_addr(uri_str).await.is_err(), "should fail");
        }
    }
}