from abc import ABC, abstractmethod
from typing import TYPE_CHECKING, Iterator, Mapping, NamedTuple, Optional
import dagster._check as check
from dagster._core.definitions.reconstruct import ReconstructableJob
from dagster._core.execution.retries import RetryMode
from dagster._core.storage.dagster_run import DagsterRun
if TYPE_CHECKING:
from dagster._core.events import DagsterEvent
from dagster._core.execution.context.system import StepExecutionContext
from dagster._core.execution.plan.state import KnownExecutionState
[docs]class StepRunRef(
NamedTuple(
"_StepRunRef",
[
("run_config", Mapping[str, object]),
("dagster_run", DagsterRun),
("run_id", str),
("retry_mode", RetryMode),
("step_key", str),
("recon_job", ReconstructableJob),
("known_state", Optional["KnownExecutionState"]),
],
)
):
"""A serializable object that specifies what's needed to hydrate a step so
that it can be executed in a process outside the plan process.
Users should not instantiate this class directly.
"""
def __new__(
cls,
run_config: Mapping[str, object],
dagster_run: DagsterRun,
run_id: str,
retry_mode: RetryMode,
step_key: str,
recon_job: ReconstructableJob,
known_state: Optional["KnownExecutionState"],
):
from dagster._core.execution.plan.state import KnownExecutionState
return super(StepRunRef, cls).__new__(
cls,
check.mapping_param(run_config, "run_config", key_type=str),
check.inst_param(dagster_run, "dagster_run", DagsterRun),
check.str_param(run_id, "run_id"),
check.inst_param(retry_mode, "retry_mode", RetryMode),
check.str_param(step_key, "step_key"),
check.inst_param(recon_job, "recon_job", ReconstructableJob),
check.opt_inst_param(known_state, "known_state", KnownExecutionState),
)
[docs]class StepLauncher(ABC):
"""A StepLauncher is responsible for executing steps, either in-process or in an external process."""
@abstractmethod
def launch_step(self, step_context: "StepExecutionContext") -> Iterator["DagsterEvent"]:
"""Args:
step_context (StepExecutionContext): The context that we're executing the step in.
Returns:
Iterator[DagsterEvent]: The events for the step.
"""