Add existing Redis instance password to new Secret

Store an external, existing Redis instance password in a Secret via the values.yaml in the same way an existing postgresql.auth.password value gets stored in a Secret.

Fixes mastodon/chart#80

templates/secret-redis.yaml

@@ -0,0 +1,15 @@
+{{- if not .Values.redis.enabled }}
+{{- if and (not .Values.redis.auth.existingSecret) (not .Values.redis.existingSecret) }}
+{{- if .Values.redis.auth.password }}
+apiVersion: v1
+kind: Secret
+metadata:
+  name: {{ include "mastodon.redis.secretName" . }}
+  labels:
+    {{- include "mastodon.labels" . | nindent 4 }}
+type: Opaque
+data:
+  redis-password: "{{ .Values.redis.auth.password | b64enc }}"
+{{- end }}
+{{- end }}
+{{- end }}

values.yaml

@@ -278,6 +278,7 @@ redis:
     # -- you must set a password; the password generated by the redis chart will be
     # rotated on each upgrade:
     password: ""
+    # setting password for an existing redis instance will store it in a new Secret
     # you can also specify the name of an existing Secret
     # with a key of redis-password set to the password you want
     # existingSecret: ""