MountVolumesFeatureStep¶

MountVolumesFeatureStep is a KubernetesFeatureConfigStep.

Creating Instance¶

MountVolumesFeatureStep takes the following to be created:

• KubernetesConf

MountVolumesFeatureStep is created when:

• KubernetesDriverBuilder is requested to build a driver pod spec
• KubernetesExecutorBuilder is requested for a pod spec for executors

Configuring Driver Pod¶

configurePod(
  pod: SparkPod): SparkPod

configurePod is part of the KubernetesFeatureConfigStep abstraction.

configurePod constructs the volumes and volume mounts from the volumes (of the KubernetesConf) and creates a new SparkPod:

• Adds the volumes to the pod specification

• Adds the volume mounts to the container specification

constructVolumes¶

constructVolumes(
  volumeSpecs: Iterable[KubernetesVolumeSpec]): Iterable[(VolumeMount, Volume)]

constructVolumes creates Kubernetes VolumeMounts and Volumes for the given KubernetesVolumeSpecs.

VolumeMounts are built based on the following (4 of 5 properties):

• mountPath
• mountReadOnly
• mountSubPath
• volumeName

Volumes are build based on the type of the volume (the remaining 5^th property).

In the end, Volumes and VolumeMounts are wired together using volumeName.

Claim Name Placeholders¶

MountVolumesFeatureStep defines OnDemand and SPARK_EXECUTOR_ID as placeholders for runtime-replaceable parts of the claim name of a KubernetesPVCVolumeConf.

These placeholders allow for templating claim names to include parts to be replaced at deployment.

When constructVolumes MountVolumesFeatureStep replaces all OnDemands with the following (using resourceNamePrefix and executorId of the KubernetesConf):

When constructVolumes MountVolumesFeatureStep replaces all SPARK_EXECUTOR_IDs with executorId of the KubernetesConf.