You can define your own custom resource and use it from context prometheus.run_gauge.labels(...).set(1)

from dagster import InitResourceContext
from dagster_prometheus import PrometheusResource
from prometheus_client import Gauge
from pydantic import PrivateAttr


class CustomPrometheusResource(PrometheusResource):
    _run_gauge: Gauge = PrivateAttr(default=None)
    def setup_for_execution(self, context: InitResourceContext) -> None:
        super().setup_for_execution(context)
        self._run_counter = Gauge(
            name='dagster_run_gauge',
            documentation='Status of Dagster runs',
            labelnames=['job_name', 'status', 'cluster'],
            registry=self._registry
        )

    @property
    def run_gauge(self):
        return self._run_gauge