add deployment.strategy to chart (#599)

Description of changes:
Add the ability to set the deployment's update strategy via chart values.


By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

Author: joejulian

templates/helm/templates/deployment.yaml.tpl

@@ -204,3 +204,6 @@ spec:
 {{ "{{- if .Values.deployment.extraVolumes }}" }}
 {{ "{{ toYaml .Values.deployment.extraVolumes | indent 8}}" }}
 {{ "{{- end }}" }}
+{{ "  {{- with .Values.deployment.strategy }}" }}
+  strategy: {{ "{{- toYaml . | nindent 4 }}" }}
+{{ "  {{- end }}" }}

templates/helm/values.yaml.tpl

@@ -41,6 +41,9 @@ deployment:
   # To have DNS options set along with hostNetwork, you have to specify DNS policy
   # explicitly to 'ClusterFirstWithHostNet'.
   dnsPolicy: ClusterFirst
+  # Set rollout strategy for deployment.
+  # See: https://kubernetes.io/docs/concepts/workloads/controllers/deployment/#strategy
+  strategy: {}
   extraVolumes: []
   extraVolumeMounts: []