from typing import Any, Dict, Iterator, List, Optional
import dateutil
from dagster import AssetMaterialization, MetadataEntry, check
from .types import DbtOutput
def _get_asset_materialization(
unique_id: str, asset_key_prefix: List[str], metadata: List[MetadataEntry]
) -> AssetMaterialization:
return AssetMaterialization(
description=f"dbt node: {unique_id}",
metadata_entries=metadata,
asset_key=asset_key_prefix + unique_id.split("."),
)
def _node_result_to_metadata(node_result: Dict[str, Any]) -> List[MetadataEntry]:
return [
MetadataEntry.text(
text=node_result["config"]["materialized"],
label="Materialization Strategy",
),
MetadataEntry.text(text=node_result["database"], label="Database"),
MetadataEntry.text(text=node_result["schema"], label="Schema"),
MetadataEntry.text(text=node_result["alias"], label="Alias"),
MetadataEntry.text(text=node_result["description"], label="Description"),
]
def _timing_to_metadata(timings: List[Dict[str, Any]]) -> List[MetadataEntry]:
metadata = []
for timing in timings:
if timing["name"] == "execute":
desc = "Execution"
elif timing["name"] == "compile":
desc = "Compilation"
else:
continue
started_at = dateutil.parser.isoparse(timing["started_at"])
completed_at = dateutil.parser.isoparse(timing["completed_at"])
duration = completed_at - started_at
metadata.extend(
[
MetadataEntry.text(
text=started_at.isoformat(timespec="seconds"), label=f"{desc} Started At"
),
MetadataEntry.text(
text=started_at.isoformat(timespec="seconds"), label=f"{desc} Completed At"
),
MetadataEntry.float(value=duration.total_seconds(), label=f"{desc} Duration"),
]
)
return metadata
def result_to_materialization(
result: Dict[str, Any],
asset_key_prefix: Optional[List[str]] = None,
docs_url: Optional[str] = None,
) -> Optional[AssetMaterialization]:
"""
This is a hacky solution that attempts to consolidate parsing many of the potential formats
that dbt can provide its results in. This is known to work for CLI Outputs for dbt versions 0.18+,
as well as RPC responses for a similar time period, but as the RPC response schema is not documented
nor enforced, this can become out of date easily.
"""
asset_key_prefix = check.opt_list_param(asset_key_prefix, "asset_key_prefix", of_type=str)
# status comes from set of fields rather than "status"
if "fail" in result:
success = not result.get("fail") and not result.get("skip") and not result.get("error")
else:
success = result["status"] == "success"
if not success:
return None
# all versions represent timing the same way
metadata = [
MetadataEntry.float(value=result["execution_time"], label="Execution Time (seconds)")
] + _timing_to_metadata(result["timing"])
# working with a response that contains the node block (RPC and CLI 0.18.x)
if "node" in result:
unique_id = result["node"]["unique_id"]
metadata += _node_result_to_metadata(result["node"])
else:
unique_id = result["unique_id"]
id_prefix = unique_id.split(".")
# only generate materializations for models
if id_prefix[0] != "model":
return None
if docs_url:
metadata = [
MetadataEntry.url(url=f"{docs_url}#!/model/{unique_id}", label="docs_url")
] + metadata
return AssetMaterialization(
description=f"dbt node: {unique_id}",
metadata_entries=metadata,
asset_key=asset_key_prefix + id_prefix,
)
[docs]def generate_materializations(
dbt_output: DbtOutput, asset_key_prefix: Optional[List[str]] = None
) -> Iterator[AssetMaterialization]:
"""
This function yields :py:class:`dagster.AssetMaterialization` events for each model created by
a dbt run command (with information parsed from a :py:class:`~DbtOutput` object).
Note that this will not work with output from the `dbt_rpc_resource`, because this resource does
not wait for a response from the RPC server before returning. Instead, use the
`dbt_rpc_sync_resource`, which will wait for execution to complete.
Examples:
.. code-block:: python
from dagster import op, Output
from dagster_dbt.utils import generate_materializations
from dagster_dbt import dbt_cli_resource, dbt_rpc_sync_resource
@op(required_resource_keys={"dbt"})
def my_custom_dbt_run(context):
dbt_output = context.resources.dbt.run()
for materialization in generate_materializations(dbt_output):
# you can modify the materialization object to add extra metadata, if desired
yield materialization
yield Output(my_dbt_output)
@job(resource_defs={{"dbt":dbt_cli_resource}})
def my_dbt_cli_job():
my_custom_dbt_run()
@job(resource_defs={{"dbt":dbt_rpc_sync_resource}})
def my_dbt_rpc_job():
my_custom_dbt_run()
"""
asset_key_prefix = check.opt_list_param(asset_key_prefix, "asset_key_prefix", of_type=str)
for result in dbt_output.result["results"]:
materialization = result_to_materialization(
result, asset_key_prefix, docs_url=dbt_output.docs_url
)
if materialization is not None:
yield materialization
