feature to prevent updating existing configmap

Author: karlnewell

chart/templates/configmap.yaml

@@ -1,7 +1,15 @@
+{{- $configMapName := printf "%s-config" (include "PolyNSI.fullname" .) }}
+
+{{- $shouldCreate := true }}
+{{- if .Values.config.checkExistence }}
+{{- $shouldCreate = not (lookup "v1" "ConfigMap" .Release.Namespace $configMapName) }}
+{{- end }}
+
+{{- if $shouldCreate }}
 apiVersion: v1
 kind: ConfigMap
 metadata:
-  name: {{ printf "%s-config" (include "PolyNSI.fullname" .) }}
+  name: {{ $configMapName }}
 #  namespace: {{ .Release.Namespace }}
 {{- if .Values.config.filesGlob }}
 binaryData:
@@ -12,4 +20,5 @@ binaryData:
 {{ else if .Values.config.inline }}
 data:
 {{.Values.config.inline | indent 2}}
-{{ end }}
+{{ end }}
+{{- end }}

chart/values.yaml

@@ -98,6 +98,7 @@ truststore:
   key: truststore.jks
 
 config:
+  checkExistence: false  # Set to true to not overwrite existing configmap.
   # either read config files from folder or use inline data, filesGlob takes precedence over inline.
   #filesGlob: "config/*"
   inline: |-