mock server, file and folder management

server/app/storage/backends.py

@@ -0,0 +1,116 @@
+from __future__ import annotations
+
+from dataclasses import dataclass
+from pathlib import Path
+from typing import Protocol
+
+import boto3
+
+from app.settings import settings
+
+
+class StorageBackendError(RuntimeError):
+    pass
+
+
+class StorageBackend(Protocol):
+    name: str
+
+    def put_bytes(self, key: str, data: bytes, *, content_type: str | None = None) -> None: ...
+    def get_bytes(self, key: str) -> bytes: ...
+    def delete(self, key: str) -> None: ...
+    def exists(self, key: str) -> bool: ...
+
+
+@dataclass(slots=True)
+class LocalFilesystemStorageBackend:
+    root: Path
+    name: str = "local"
+
+    def __post_init__(self) -> None:
+        self.root = self.root.expanduser().resolve()
+        self.root.mkdir(parents=True, exist_ok=True)
+
+    def _path(self, key: str) -> Path:
+        path = (self.root / key).resolve()
+        if not path.is_relative_to(self.root):
+            raise StorageBackendError("Storage key escapes local storage root")
+        return path
+
+    def put_bytes(self, key: str, data: bytes, *, content_type: str | None = None) -> None:
+        path = self._path(key)
+        path.parent.mkdir(parents=True, exist_ok=True)
+        path.write_bytes(data)
+
+    def get_bytes(self, key: str) -> bytes:
+        path = self._path(key)
+        if not path.exists() or not path.is_file():
+            raise StorageBackendError("Stored object does not exist")
+        return path.read_bytes()
+
+    def delete(self, key: str) -> None:
+        path = self._path(key)
+        if path.exists() and path.is_file():
+            path.unlink()
+
+    def exists(self, key: str) -> bool:
+        path = self._path(key)
+        return path.exists() and path.is_file()
+
+
+@dataclass(slots=True)
+class S3StorageBackend:
+    bucket: str
+    endpoint_url: str
+    region_name: str
+    access_key_id: str
+    secret_access_key: str
+    name: str = "s3"
+
+    @property
+    def client(self):
+        return boto3.client(
+            "s3",
+            endpoint_url=self.endpoint_url,
+            region_name=self.region_name,
+            aws_access_key_id=self.access_key_id,
+            aws_secret_access_key=self.secret_access_key,
+        )
+
+    def put_bytes(self, key: str, data: bytes, *, content_type: str | None = None) -> None:
+        kwargs = {"Bucket": self.bucket, "Key": key, "Body": data}
+        if content_type:
+            kwargs["ContentType"] = content_type
+        self.client.put_object(**kwargs)
+
+    def get_bytes(self, key: str) -> bytes:
+        try:
+            obj = self.client.get_object(Bucket=self.bucket, Key=key)
+            return obj["Body"].read()
+        except Exception as exc:  # pragma: no cover - depends on S3 backend
+            raise StorageBackendError(str(exc)) from exc
+
+    def delete(self, key: str) -> None:
+        self.client.delete_object(Bucket=self.bucket, Key=key)
+
+    def exists(self, key: str) -> bool:
+        try:
+            self.client.head_object(Bucket=self.bucket, Key=key)
+            return True
+        except Exception:
+            return False
+
+
+def get_storage_backend() -> StorageBackend:
+    backend = settings.file_storage_backend.lower().strip()
+    if backend in {"local", "filesystem", "fs"}:
+        return LocalFilesystemStorageBackend(Path(settings.file_storage_local_root))
+    if backend in {"s3", "garage"}:
+        return S3StorageBackend(
+            bucket=settings.file_storage_s3_bucket or settings.s3_bucket,
+            endpoint_url=settings.file_storage_s3_endpoint_url or settings.s3_endpoint_url,
+            region_name=settings.file_storage_s3_region or settings.s3_region,
+            access_key_id=settings.file_storage_s3_access_key_id or settings.s3_access_key_id,
+            secret_access_key=settings.file_storage_s3_secret_access_key or settings.s3_secret_access_key,
+        )
+    raise StorageBackendError(f"Unsupported file storage backend: {settings.file_storage_backend}")