auto-save 2026-04-13 19:12 (+1)

api/app/services/storage.py

@@ -0,0 +1,60 @@
+"""MinIO / S3 presigned URL helper.
+
+We use boto3 because MinIO speaks the S3 protocol and boto3 is the de-facto
+client. Generating presigned multipart upload URLs lets the browser upload
+files >100MB directly to MinIO without going through the FastAPI process,
+which avoids body-size limits and streaming-into-RAM issues.
+"""
+
+import boto3
+from botocore.client import Config
+from ..config import settings
+
+
+def s3_client():
+    return boto3.client(
+        "s3",
+        endpoint_url=("https" if settings.minio_secure else "http")
+        + "://"
+        + settings.minio_endpoint,
+        aws_access_key_id=settings.minio_access_key,
+        aws_secret_access_key=settings.minio_secret_key,
+        region_name=settings.minio_region,
+        config=Config(signature_version="s3v4", s3={"addressing_style": "path"}),
+    )
+
+
+def ensure_bucket() -> None:
+    client = s3_client()
+    try:
+        client.head_bucket(Bucket=settings.minio_bucket)
+    except Exception:
+        client.create_bucket(Bucket=settings.minio_bucket)
+
+
+def presign_put(object_key: str, content_type: str, expires: int = 3600) -> str:
+    """Single-PUT presigned URL — for files small enough not to need multipart.
+
+    For multipart (files >100MB), the frontend should use the AWS SDK's
+    @aws-sdk/lib-storage Upload helper, which can sign each part itself once
+    we hand it the credentials. For MVP we keep things simple with single-PUT
+    + a 500 MB cap.
+    """
+    return s3_client().generate_presigned_url(
+        "put_object",
+        Params={
+            "Bucket": settings.minio_bucket,
+            "Key": object_key,
+            "ContentType": content_type,
+        },
+        ExpiresIn=expires,
+        HttpMethod="PUT",
+    )
+
+
+def presign_get(object_key: str, expires: int = 3600) -> str:
+    return s3_client().generate_presigned_url(
+        "get_object",
+        Params={"Bucket": settings.minio_bucket, "Key": object_key},
+        ExpiresIn=expires,
+    )