Add PodDisruptionBudget to chart

[csp33]

Purpose of this PR

When running the operator in production, it would be nice to have a PDB to ensure HA and prevent service disruption.

Proposed changes:

• Allow deploying a PDB within the chart

Change Category

Indicate the type of change by marking the applicable boxes:

• Bugfix (non-breaking change which fixes an issue)
• Feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that could affect existing functionality)
• Documentation update

Rationale

Here's a blog post that summarizes the main advantages of PDBs

Checklist

Before submitting your PR, please review the following:

• I have conducted a self-review of my own code.
• I have updated documentation accordingly.
• I have added tests that prove my changes are effective or that my feature works.
• Existing unit tests pass locally with my changes.

Additional Notes

x

[vara-bonthu]

Thanks for the PR @csp33 !

/approve

[ChenYi015]

@csp33 What's the minimum k8s version needed to support this feature?

[ChenYi015]

Thanks for the PR, I have left some comments.

[ChenYi015]

• Could you rename pdb to podDisruptionBudget, and use podDisruptionBudget.enable in order to be consistent with other options like webhook.enable, metrics.enable and podMonitor.enable.
• You can use # -- to add comments, and it will be rendered in chart README.
• Could you place this option after podMonitor section since it is a less common configuration.

Suggested change

	# Whether to deploy a PodDisruptionBudget. Make sure you deploy at least 2 replicas before enabling this.
	pdb:
	enabled: false
	minAvailable: 1
	podDisruptionBudget:
	# -- Specifies whether to enable pod disruption budget.
	# Ref: [Specifying a Disruption Budget for your Application](https://kubernetes.io/docs/tasks/run-application/configure-pdb/).
	enable: false
	# -- The number of pods that must be available.
	# Require `replicaCount` to be greater than 1.
	minAvailable: 1

[csp33]

done

[ChenYi015]

Cloud you rename this file to poddisruptionbudget.yaml and the test file to poddisruptionbudget_test.yaml respectively.

Besides, you can add a condition to test whether replica count is greater than 1, since this is needed by the feature.

Suggested change

	{{- if $.Values.pdb.enabled }}
	apiVersion: policy/v1
	kind: PodDisruptionBudget
	metadata:
	name: {{ include "spark-operator.fullname" . }}-pdb
	labels:
	{{- include "spark-operator.labels" . | nindent 4 }}
	spec:
	selector:
	matchLabels:
	{{- include "spark-operator.selectorLabels" . | nindent 6 }}
	minAvailable: {{ $.Values.pdb.minAvailable }}
	{{- end }}
	{{- if .Values.podDisruptionBudget.enable }}
	{{- if (gt .ReplicaCount 1) }}
	apiVersion: policy/v1
	kind: PodDisruptionBudget
	metadata:
	name: {{ include "spark-operator.fullname" . }}-pdb
	labels:
	{{- include "spark-operator.labels" . | nindent 4 }}
	spec:
	selector:
	matchLabels:
	{{- include "spark-operator.selectorLabels" . | nindent 6 }}
	minAvailable: {{ .Values.podDisruptionBudget.minAvailable }}
	{{- else }}
	{{- fail "replicaCount must be greater than 1 to enable pod disruption budget" }}
	{{- end }}
	{{- end }}

[csp33]

done

[csp33]

@csp33 What's the minimum k8s version needed to support this feature?

1.21
https://kubernetes.io/docs/tasks/run-application/configure-pdb/

[google-oss-prow]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: ChenYi015, peter-mcclonski, vara-bonthu

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• OWNERS [vara-bonthu]

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[ChenYi015]

/lgtm