[stable/grafana] Ability to give a subpath for an extra secret (#22145)

* Ability to give a subpath for an extra secret

Add the ability to give a subpath for an extra secret.
Use case:
We use a secret with multiple data and we don't want to override the directory /etc/ssl/certs/ but just add a file. SubPath in volumeMount help to achive this

Signed-off-by: Guillaume Audic <audic.gui@gmail.com>

* [grafana] Add a comment in the values for subPath & Bump chart version

Signed-off-by: Guillaume Audic <audic.gui@gmail.com>

stable/grafana/Chart.yaml

@@ -1,6 +1,6 @@
 apiVersion: v1
 name: grafana
-version: 5.0.16
+version: 5.0.18
 appVersion: 6.7.3
 kubeVersion: "^1.8.0-0"
 description: The leading tool for querying and visualizing time series and metrics.

stable/grafana/templates/_pod.tpl

@@ -202,6 +202,7 @@ containers:
       - name: {{ .name }}
         mountPath: {{ .mountPath }}
         readOnly: {{ .readOnly }}
+        subPath: {{ .subPath | default "" }}
     {{- end }}
     {{- range .Values.extraVolumeMounts }}
       - name: {{ .name }}

stable/grafana/values.yaml

@@ -281,6 +281,7 @@ extraSecretMounts: []
   #   mountPath: /etc/secrets
   #   secretName: grafana-secret-files
   #   readOnly: true
+  #   subPath: ""
 
 ## Additional grafana server volume mounts
 # Defines additional volume mounts.