Route Writes To Multiple Groups

Goal

Route one batch's items to more than one output group in the same Zarr store.

Declare The Groups

get_batch_groups is a BaseIngestor hook. Override it to name more than the single default group:

# Stable, sorted list -> these become the zarr group paths in the store
def get_batch_groups(self, items: Sequence[Any], ctx: PluginContext) -> list[str]:
    return ["quality", "sst"]

Firecube calls the per-group write hook once for each name returned here, passing the full batch item list every time, so the plugin selects what belongs to the group it was called for. The list must be stable and sorted so the group set stays consistent across runs; each name becomes its own group path in the Zarr store.

Route Writes Per Template

Declaring the groups is the same everywhere; writing to them is template-specific:

• GenericZarrIngestor: branch on group inside build_dataset — see Implement GenericZarrIngestor.
• DirectZarrIngestor: declare a matching ZarrGroupSpec per group in zarr_schema, then tag each WriteIntent with the group it targets — see Implement DirectZarrIngestor.

Verify

Confirm the override returns the declared groups, without needing a template or a full ingest run:

uv run python -c "
from firecube_my_plugin.ingestor import MyPlugin
print(MyPlugin.get_batch_groups(None, [], None))
"

Expected output:

['quality', 'sst']

This confirms the override itself. Confirming that Firecube actually writes each group to the store needs the chosen template's own Verify section, once its writes are wired up.

Next Steps

• Implement GenericZarrIngestor — the template that branches on group in build_dataset
• Implement DirectZarrIngestor — the template that tags each WriteIntent with group
• Plugin Templates — look up zarr_schema and WriteIntent fields