Set Content-Type when upload Zarr entries

dandi/dandiapi.py

@@ -2015,18 +2015,27 @@ def match(self, pattern: str) -> bool:
                 return False
         return True
 
+    @property
+    def download_url(self) -> str:
+        """
+        .. versionadded:: 0.67.0
+
+        The URL from which the entry can be downloaded
+        """
+        return str(
+            URL(self.client.get_url(f"/zarr/{self.zarr_id}/files/")).with_query(
+                {"prefix": str(self), "download": "true"}
+            )
+        )
+
     def get_download_file_iter(
         self, chunk_size: int = MAX_CHUNK_SIZE
     ) -> Callable[[int], Iterator[bytes]]:
         """
         Returns a function that when called (optionally with an offset into the
         file to start downloading at) returns a generator of chunks of the file
         """
-        url = str(
-            URL(self.client.get_url(f"/zarr/{self.zarr_id}/files/")).with_query(
-                {"prefix": str(self), "download": "true"}
-            )
-        )
+        url = self.download_url
 
         def downloader(start_at: int = 0) -> Iterator[bytes]:
             lgr.debug("Starting download from %s", url)

dandi/files/zarr.py

@@ -6,6 +6,7 @@
 from contextlib import closing
 from dataclasses import dataclass, field, replace
 from datetime import datetime
+import json
 import os
 import os.path
 from pathlib import Path
@@ -558,13 +559,16 @@ def _upload_zarr_file(
     storage_session: RESTFullAPIClient, upload_url: str, item: UploadItem
 ) -> int:
     try:
+        headers = {"Content-MD5": item.base64_digest}
+        if item.content_type is not None:
+            headers["Content-Type"] = item.content_type
         with item.filepath.open("rb") as fp:
             storage_session.put(
                 upload_url,
                 data=fp,
                 json_resp=False,
                 retry_if=_retry_zarr_file,
-                headers={"Content-MD5": item.base64_digest},
+                headers=headers,
             )
     except Exception:
         post_upload_size_check(item.filepath, item.size, True)
@@ -643,22 +647,38 @@ class UploadItem:
     filepath: Path
     digest: str
     size: int
+    content_type: str | None
 
     @classmethod
     def from_entry(cls, e: LocalZarrEntry, digest: str) -> UploadItem:
+        if e.name in {".zarray", ".zattrs", ".zgroup", ".zmetadata"}:
+            try:
+                with e.filepath.open("rb") as fp:
+                    json.load(fp)
+            except Exception:
+                content_type = None
+            else:
+                content_type = "application/json"
+        else:
+            content_type = None
         return cls(
             entry_path=str(e),
             filepath=e.filepath,
             digest=digest,
             size=pre_upload_size_check(e.filepath),
+            content_type=content_type,
         )
 
     @property
     def base64_digest(self) -> str:
         return b64encode(bytes.fromhex(self.digest)).decode("us-ascii")
 
-    def upload_request(self) -> dict[str, str]:
-        return {"path": self.entry_path, "base64md5": self.base64_digest}
+    def upload_request(self) -> dict[str, str | None]:
+        return {
+            "path": self.entry_path,
+            "base64md5": self.base64_digest,
+            "content_type": self.content_type,
+        }
 
 
 def _cmp_digests(

dandi/tests/test_files.py

@@ -507,6 +507,18 @@ def test_upload_zarr_with_excluded_dotfiles(
     ]
 
 
+def test_upload_zarr_entry_content_type(new_dandiset, tmp_path):
+    filepath = tmp_path / "example.zarr"
+    zarr.save(filepath, np.arange(1000), np.arange(1000, 0, -1))
+    zf = dandi_file(filepath)
+    assert isinstance(zf, ZarrAsset)
+    asset = zf.upload(new_dandiset.dandiset, {"description": "A test Zarr"})
+    assert isinstance(asset, RemoteZarrAsset)
+    e = asset.get_entry_by_path(".zgroup")
+    r = new_dandiset.client.get(e.download_url, json_resp=False)
+    assert r.headers["Content-Type"] == "application/json"
+
+
 def test_validate_deep_zarr(tmp_path: Path) -> None:
     zarr_path = tmp_path / "foo.zarr"
     zarr.save(zarr_path, np.arange(1000), np.arange(1000, 0, -1))