feat(helm): add support for priorityClassName (#1008)

# Description

Add support for configuring `priorityClassName` for the agent and
operator pods.

## Related Issue

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Additionally, make sure that the issue is assigned to you before
submitting this pull request.

## Checklist

- [ ] I have read the [contributing
documentation](https://retina.sh/docs/contributing).
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- [ ] I have correctly attributed the author(s) of the code.
- [ ] I have tested the changes locally.
- [ ] I have followed the project's style guidelines.
- [ ] I have updated the documentation, if necessary.
- [ ] I have added tests, if applicable.

---

Please refer to the [CONTRIBUTING.md](../CONTRIBUTING.md) file for more
information on how to contribute to this project.

deploy/hubble/manifests/controller/helm/retina/templates/agent/daemonset.yaml

@@ -23,6 +23,9 @@ spec:
     spec:
       hostNetwork: true
       serviceAccountName: {{ .Values.serviceAccount.name }}
+      {{- if .Values.priorityClassName }}
+      priorityClassName: {{ .Values.priorityClassName }}
+      {{- end }}
       nodeSelector:
         kubernetes.io/os: linux
       {{- with .Values.imagePullSecrets }}
@@ -170,6 +173,9 @@ spec:
     spec:
       serviceAccountName: {{ .Values.serviceAccount.name }}
       {{- with .Values.imagePullSecrets }}
+      {{- if .Values.priorityClassName }}
+      priorityClassName: {{ .Values.priorityClassName }}
+      {{- end }}
       imagePullSecrets:
         {{- toYaml . | nindent 8 }}
       {{- end }}      

deploy/hubble/manifests/controller/helm/retina/templates/operator/deployment.yaml

@@ -103,6 +103,9 @@ spec:
               cpu: 250m
               memory: 250Mi
       serviceAccountName: retina-operator
+      {{- if .Values.operator.priorityClassName }}
+      priorityClassName: {{ .Values.operator.priorityClassName }}
+      {{- end }}
       terminationGracePeriodSeconds: 10
       volumes:
         - name: retina-operator-config

deploy/hubble/manifests/controller/helm/retina/values.yaml

@@ -118,6 +118,11 @@ securityContext:
   windowsOptions:
     runAsUserName: "NT AUTHORITY\\SYSTEM"
 
+## @param priorityClassName [string] Indicates the pod's priority
+## Ref: https://kubernetes.io/docs/concepts/scheduling-eviction/pod-priority-preemption/
+##
+priorityClassName: ""
+
 service:
   type: ClusterIP
   port: 10093

deploy/legacy/manifests/controller/helm/retina/templates/daemonset.yaml

@@ -26,6 +26,9 @@ spec:
     spec:
       hostNetwork: true
       serviceAccountName: {{ .Values.serviceAccount.name }}
+      {{- if .Values.priorityClassName }}
+      priorityClassName: {{ .Values.priorityClassName }}
+      {{- end }}
       initContainers:
         - name: init-retina
           image: {{ .Values.image.initRepository }}:{{ .Values.image.tag }}
@@ -183,6 +186,9 @@ spec:
       namespace: {{ .Values.namespace }}
     spec:
       serviceAccountName: {{ .Values.serviceAccount.name }}
+      {{- if .Values.priorityClassName }}
+      priorityClassName: {{ .Values.priorityClassName }}
+      {{- end }}
       securityContext:
         windowsOptions:
           hostProcess: true

deploy/legacy/manifests/controller/helm/retina/templates/operator.yaml

@@ -97,6 +97,9 @@ spec:
           resources:
             {{- toYaml .Values.operator.resources | nindent 12 }}
       serviceAccountName: {{ .Values.operator.name }}
+      {{- if .Values.operator.priorityClassName }}
+      priorityClassName: {{ .Values.operator.priorityClassName }}
+      {{- end }}
       terminationGracePeriodSeconds: 10
       volumes:
         - name: "{{ .Values.operator.name }}-config"

deploy/legacy/manifests/controller/helm/retina/values.yaml

@@ -192,6 +192,11 @@ livenessProbe: {}
   # failureThreshold: 5
   # successThreshold: 1
 
+## @param priorityClassName [string] Indicates the pod's priority
+## Ref: https://kubernetes.io/docs/concepts/scheduling-eviction/pod-priority-preemption/
+##
+priorityClassName: ""
+
 metrics:
   ## Prometheus Service Monitor
   ## ref: https://github.com/coreos/prometheus-operator/blob/master/Documentation/api.md#endpoint
@@ -278,4 +283,4 @@ metrics:
     metricRelabelings:
       - sourceLabels: [__name__]
         action: keep
-        regex: (.*)
+        regex: (.*)