Health Checks

dagster-rocky 0.4 ships rocky_healthcheck() — a wrapper around rocky doctor suitable for Dagster+ code-location startup probes, custom asset checks, and custom ops.

rocky_healthcheck(rocky) -> HealthcheckResult

Calls RockyResource.doctor() and translates the outcome into a HealthcheckResult dataclass with three cases:

healthy	doctor_result	error	Meaning
True	<DoctorResult>	None	All checks non-critical
False	<DoctorResult>	None	At least one check is critical
False	None	<message>	The binary failed to invoke

Warning-status checks are treated as non-blocking; only critical fails the health probe.

Quickstart

from dagster_rocky import RockyResource, rocky_healthcheck

rocky = RockyResource(config_path="rocky.toml")
outcome = rocky_healthcheck(rocky)

if outcome.healthy:
    print("Rocky is healthy")
elif outcome.doctor_result is not None:
    print("Doctor reports critical issues:")
    for check in outcome.doctor_result.checks:
        if check.status == "critical":
            print(f"  - {check.name}: {check.message}")
else:
    print(f"Rocky binary failed to invoke: {outcome.error}")

As a Dagster asset check

import dagster as dg
from dagster_rocky import RockyResource, rocky_healthcheck

@dg.asset_check(asset=dg.AssetKey(["rocky", "health"]))
def rocky_healthcheck_asset(context, rocky: RockyResource):
    outcome = rocky_healthcheck(rocky)
    return dg.AssetCheckResult(
        passed=outcome.healthy,
        severity=dg.AssetCheckSeverity.ERROR if not outcome.healthy else dg.AssetCheckSeverity.WARN,
        metadata={
            "error": outcome.error or "",
            "checks": (
                [c.name for c in outcome.doctor_result.checks]
                if outcome.doctor_result
                else []
            ),
        },
    )

As a Dagster+ code-location health probe

Dagster+ supports custom health endpoints for code locations. Wire the healthcheck into your code location startup:

from dagster_rocky import rocky_healthcheck

def is_code_location_healthy() -> bool:
    rocky = RockyResource(config_path="rocky.toml")
    return rocky_healthcheck(rocky).healthy

If is_code_location_healthy() returns False, Dagster+ marks the code location as unhealthy and routes traffic away from it.

Why a wrapper, not a method on RockyResource?

rocky_healthcheck lives outside RockyResource because the resource is a frozen Pydantic model — extending it with new methods on every iteration churns the resource module. The standalone wrapper pattern keeps health probes decoupled from the core resource shape and can be promoted to a method later if it stabilizes.