charmed-slurm-oci-runtime-interface

Usage

This package provides the integration interface implementation for the slurm_oci_runtime interface. It enables OCI runtime charms - for example, Apptainer - to share their runtime configuration with slurm_oci_runtime requirers like the slurmctld application. The slurm_oci_runtime requirer consumes this data to manage the oci.conf configuration file. When the integration is broken, the requirer is notified so it can remove the OCI runtime configuration.

Installation

Add charmed-slurm-oci-runtime-interface to your Python dependencies. Then in your Python code, import as:

from charmed_slurm_oci_runtime_interface import (
    OCIRuntimeData,
    OCIRuntimeProvider,
    OCIRuntimeRequirer,
)

Direction

flowchart TD
    Provider -- type, executable_path --> Requirer

Behavior

Data is exchanged through the Juju integration application databag. The OCI runtime provider places its configuration - an OCIRuntimeData structure - in its application databag. The slurmctld requirer reads this data to construct the oci.conf configuration file.

Provider

• Is expected to call set_oci_runtime_data to publish OCIRuntimeData containing the OCI runtime configuration.
• Is expected to only interact with the integration as the application leader.
• Is expected to emit SlurmctldConnectedEvent when the relation to slurmctld is created.
• Is expected to emit SlurmctldReadyEvent when controller data from slurmctld is available.

Requirer

• Is expected to emit OCIRuntimeReadyEvent when OCI runtime data is available in the application databag.
• Is expected to emit OCIRuntimeDisconnectedEvent when the OCI runtime application is disconnected.
• Is expected to call get_oci_runtime_data to retrieve OCIRuntimeData.
• Is expected to only process events as the application leader.

Example integration data

provider:
  app:
    type: '"apptainer"'
    executable_path: '"/usr/bin/apptainer"'
  unit: {}
requirer:
  app:
    auth_secret_id: "secret:abc123"
    controllers: '["10.0.0.1"]'
    slurmconfig: '{"slurm.conf": {...}}'
  unit: {}

Example usages

Provider charm

"""Example OCI runtime charm providing runtime configuration to slurmctld."""

import ops
from charmed_slurm_oci_runtime_interface import OCIRuntimeData, OCIRuntimeProvider


class ApptainerCharm(ops.CharmBase):
    """An OCI runtime charm that provides configuration to slurmctld."""

    def __init__(self, framework: ops.Framework) -> None:
        super().__init__(framework)
        self.oci_runtime = OCIRuntimeProvider(self, "slurm-oci-runtime")
        self.framework.observe(
            self.oci_runtime.on.slurmctld_ready, self._on_slurmctld_ready
        )

    def _on_slurmctld_ready(self, event: ops.RelationEvent) -> None:
        """Publish OCI runtime data once slurmctld is connected."""
        self.oci_runtime.set_oci_runtime_data(
            OCIRuntimeData(type="apptainer", executable_path="/usr/bin/apptainer")
        )

Requirer charm

"""Example slurmctld charm consuming OCI runtime configuration."""

import ops
from charmed_slurm_oci_runtime_interface import OCIRuntimeData, OCIRuntimeRequirer


class SlurmctldCharm(ops.CharmBase):
    """The slurmctld charm that consumes OCI runtime configuration."""

    def __init__(self, framework: ops.Framework) -> None:
        super().__init__(framework)
        self.oci_runtime = OCIRuntimeRequirer(self, "slurm-oci-runtime")
        self.framework.observe(
            self.oci_runtime.on.oci_runtime_ready, self._on_oci_runtime_ready
        )
        self.framework.observe(
            self.oci_runtime.on.oci_runtime_disconnected,
            self._on_oci_runtime_disconnected,
        )

    def _on_oci_runtime_ready(self, event: ops.RelationEvent) -> None:
        """Handle when OCI runtime data is available."""
        data: OCIRuntimeData = self.oci_runtime.get_oci_runtime_data()
        # Use data.type and data.executable_path to write oci.conf

    def _on_oci_runtime_disconnected(self, event: ops.RelationEvent) -> None:
        """Handle when OCI runtime is disconnected."""