Add CLI for converting v2 metadata to v3

.github/workflows/gpu_test.yml

@@ -30,6 +30,8 @@ jobs:
 
     steps:
     - uses: actions/checkout@v4
+      with:
+        fetch-depth: 0  # grab all branches and tags
     # - name: cuda-toolkit
     #   uses: Jimver/cuda-toolkit@v0.2.16
     #   id: cuda-toolkit

pyproject.toml

@@ -68,6 +68,7 @@ remote = [
 gpu = [
     "cupy-cuda12x",
 ]
+cli = ["typer"]
 # Development extras
 test = [
     "coverage",
@@ -113,6 +114,9 @@ docs = [
     'pytest'
 ]
 
+[project.scripts]
+zarr-converter = "zarr.core.metadata.converter.cli:app"
+
 
 [project.urls]
 "Bug Tracker" = "https://github.com/zarr-developers/zarr-python/issues"
@@ -159,7 +163,7 @@ deps = ["minimal", "optional"]
 
 [tool.hatch.envs.test.overrides]
 matrix.deps.dependencies = [
-  {value = "zarr[remote, remote_tests, test, optional]", if = ["optional"]}
+  {value = "zarr[remote, remote_tests, test, optional, cli]", if = ["optional"]}
 ]
 
 [tool.hatch.envs.test.scripts]

src/zarr/core/metadata/converter/cli.py

@@ -0,0 +1,112 @@
+import logging
+from typing import Annotated, Literal, cast
+
+import typer
+
+from zarr.core.metadata.converter.converter_v2_v3 import convert_v2_to_v3, remove_metadata
+from zarr.core.sync import sync
+
+app = typer.Typer()
+
+logger = logging.getLogger(__name__)
+
+
+def _set_logging_config(verbose: bool) -> None:
+    if verbose:
+        lvl = logging.INFO
+    else:
+        lvl = logging.WARNING
+    fmt = "%(message)s"
+    logging.basicConfig(level=lvl, format=fmt)
+
+
+def _set_verbose_level() -> None:
+    logging.getLogger().setLevel(logging.INFO)
+
+
+@app.command()  # type: ignore[misc]
+def convert(
+    store: Annotated[
+        str,
+        typer.Argument(
+            help="Store or path to directory in file system or name of zip file e.g. 'data/example-1.zarr', 's3://example-bucket/example'..."
+        ),
+    ],
+    path: Annotated[str | None, typer.Option(help="The path within the store to open")] = None,
+    dry_run: Annotated[
+        bool,
+        typer.Option(
+            help="Enable a dry-run: files that would be converted are logged, but no new files are actually created."
+        ),
+    ] = False,
+) -> None:
+    """Convert all v2 metadata in a zarr hierarchy to v3. This will create a zarr.json file at each level
+    (for every group / array). V2 files (.zarray, .zattrs etc.) will be left as-is.
+    """
+    if dry_run:
+        _set_verbose_level()
+        logger.info(
+            "Dry run enabled - no new files will be created. Log of files that would be created on a real run:"
+        )
+
+    convert_v2_to_v3(store=store, path=path, dry_run=dry_run)
+
+
+@app.command()  # type: ignore[misc]
+def clear(
+    store: Annotated[
+        str,
+        typer.Argument(
+            help="Store or path to directory in file system or name of zip file e.g. 'data/example-1.zarr', 's3://example-bucket/example'..."
+        ),
+    ],
+    zarr_format: Annotated[
+        int,
+        typer.Argument(
+            help="Which format's metadata to remove - 2 or 3.",
+            min=2,
+            max=3,
+        ),
+    ],
+    path: Annotated[str | None, typer.Option(help="The path within the store to open")] = None,
+    dry_run: Annotated[
+        bool,
+        typer.Option(
+            help="Enable a dry-run: files that would be deleted are logged, but no files are actually removed."
+        ),
+    ] = False,
+) -> None:
+    """Remove all v2 (.zarray, .zattrs, .zgroup, .zmetadata) or v3 (zarr.json) metadata files from the given Zarr.
+    Note - this will remove metadata files at all levels of the hierarchy (every group and array).
+    """
+    if dry_run:
+        _set_verbose_level()
+        logger.info(
+            "Dry run enabled - no files will be deleted. Log of files that would be deleted on a real run:"
+        )
+
+    sync(
+        remove_metadata(
+            store=store, zarr_format=cast(Literal[2, 3], zarr_format), path=path, dry_run=dry_run
+        )
+    )
+
+
+@app.callback()  # type: ignore[misc]
+def main(
+    verbose: Annotated[
+        bool,
+        typer.Option(
+            help="enable verbose logging - will print info about metadata files being deleted / saved."
+        ),
+    ] = False,
+) -> None:
+    """
+    Convert metadata from v2 to v3. See available commands below - access help for individual commands with
+    zarr-converter COMMAND --help.
+    """
+    _set_logging_config(verbose)
+
+
+if __name__ == "__main__":
+    app()