updated kyverno deployment strategy

[vineethvanga18]

Signed-off-by: vineethvanga18 reddy.8@iitj.ac.in

Related issue

fixes #1982

What type of PR is this

/kind bug

Proposed Changes

kyverno rolling update strategy updated to maxSurge: 1, maxUnavailable: 40%

Proof Manifests

charts/kyverno/templates/deployment.yaml

kind: Deployment
metadata:
  name: {{ template "kyverno.fullname" . }}
  labels: {{ include "kyverno.labels" . | nindent 4 }}
    app: kyverno
  namespace: {{ template "kyverno.namespace" . }}
spec:
  ...
  ...
  {{- if .Values.updateStrategy }}
  strategy:
    {{ toYaml .Values.updateStrategy | nindent 4 | trim }}
  {{- end }}

charts/kyverno/values.yaml

updateStrategy:
  rollingUpdate:
    maxSurge: 1
    maxUnavailable: 40%
  type: RollingUpdate

definitions/manifest/deployment.yaml

kind: Deployment
metadata:
  labels:
    app: kyverno
    # do not remove
    app.kubernetes.io/name: kyverno
  namespace: kyverno
  name: kyverno
spec:
  ...
  ...
  strategy:
    type: RollingUpdate
    rollingUpdate:
      maxUnavailable: 40%
      maxSurge: 1

To test the changes

1. Install kyverno
2. Now update/change(image tag or any) this deployment
3. As the maxSurge is 1 and maxUnavailable is 40%. The deployment is first scaled up and then old pod gets terminated ensuring availability.

Checklist

• I have read the contributing guidelines.
• [] I have added tests that prove my fix is effective or that my feature works.
• [] My PR contains new or altered behavior to Kyverno and
  • [] I have added or changed the documentation myself in an existing PR and the link is:
  • [] I have raised an issue in kyverno/website to track the doc update and the link is:
  • [] I have read the PR documentation guide and followed the process including adding proof manifests to this PR.

Further Comments

[treydock]

@vineethvanga18 Maybe add something to Helm chart too? I had suggested such a change in #1985 but here might work too.

[vyankyGH]

@vineethvanga18 - Please add Proof manifest for the PR. What are the steps get followed to test this changes?

[vyankyGH]

Hi @vineethvanga18 can we make it configurable for the helm chat. we don't want something fix value, user can configure dynamically.