Adds default selectorLabels if not otherwise specified.

If someone defines one or more entries in the
`topologySpreadConstraints` list and does not define the
`labelSelectors.matchLabels` keys then default values will be added.
Most people are likely going to want the default selectorLabels so the
spread constraints match what they are deploying with this chart.

charts/vector/templates/_pod.tpl

@@ -174,6 +174,13 @@ tolerations:
 {{- end }}
 {{- with  .Values.topologySpreadConstraints }}
 topologySpreadConstraints:
+{{- range $_, $entry := . }}
+{{- if not (dig "labelSelectors" "matchLabels" false $entry) }}
+  {{- $ls := "labelSelectors:\n  matchLabels: {}" | fromYaml }}
+  {{- $_ := set $ls.labelSelectors "matchLabels" (include "vector.selectorLabels" $ | fromYaml) }}
+  {{- $entry := merge $entry $ls }}
+{{- end }}
+{{- end }}
 {{- toYaml . | nindent 2 }}
 {{- end }}
 volumes:

charts/vector/values.yaml

@@ -232,6 +232,8 @@ affinity: {}
 
 # topologySpreadConstraints -- Configure [topology spread constraints](https://kubernetes.io/docs/concepts/scheduling-eviction/topology-spread-constraints/)
 # for Vector Pods. Valid for the "Aggregator" and "Stateless-Aggregator" roles.
+#
+# If there are no "selectorLabels.matchLabels" are defined then defaults will be used to match the selectorLabels of this instance.
 topologySpreadConstraints: []
 
 # Configuration for Vector's Service.