[stable/prometheus] Add option to configure subpath on server volume mounts (#8113)

* Add subpath support to prometheus

Signed-off-by: Flávio Ferreira <flaviommferreira@gmail.com>

* Bump prometheus chart version

Signed-off-by: Flávio Ferreira <flaviommferreira@gmail.com>

* Bump chart version

Signed-off-by: Flávio Ferreira <flaviommferreira@gmail.com>

* Add example of subPath to prometheus values file

Signed-off-by: Flávio Ferreira <flaviommferreira@gmail.com>

stable/prometheus/Chart.yaml

@@ -1,5 +1,5 @@
 name: prometheus
-version: 7.3.0
+version: 7.3.1
 appVersion: 2.4.3
 description: Prometheus is a monitoring system and time series database.
 home: https://prometheus.io/

stable/prometheus/templates/server-deployment.yaml

@@ -73,6 +73,7 @@ spec:
           {{- range .Values.configmapReload.extraConfigmapMounts }}
             - name: {{ $.Values.configmapReload.name }}-{{ .name }}
               mountPath: {{ .mountPath }}
+              subPath: {{ .subPath }}
               readOnly: {{ .readOnly }}
           {{- end }}
 
@@ -122,16 +123,19 @@ spec:
           {{- range .Values.server.extraHostPathMounts }}
             - name: {{ .name }}
               mountPath: {{ .mountPath }}
+              subPath: {{ .subPath }}
               readOnly: {{ .readOnly }}
           {{- end }}
           {{- range .Values.server.extraConfigmapMounts }}
             - name: {{ $.Values.server.name }}-{{ .name }}
               mountPath: {{ .mountPath }}
+              subPath: {{ .subPath }}
               readOnly: {{ .readOnly }}
           {{- end }}
           {{- range .Values.server.extraSecretMounts }}
             - name: {{ .name }}
               mountPath: {{ .mountPath }}
+              subPath: {{ .subPath }}
               readOnly: {{ .readOnly }}
           {{- end }}
     {{- if .Values.server.nodeSelector }}

stable/prometheus/values.yaml

@@ -230,6 +230,7 @@ configmapReload:
   extraConfigmapMounts: []
     # - name: prometheus-alerts
     #   mountPath: /etc/alerts.d
+    #   subPath: ""
     #   configMap: prometheus-alerts
     #   readOnly: true
 
@@ -507,12 +508,14 @@ server:
   extraHostPathMounts: []
     # - name: certs-dir
     #   mountPath: /etc/kubernetes/certs
+    #   subPath: ""
     #   hostPath: /etc/kubernetes/certs
     #   readOnly: true
 
   extraConfigmapMounts: []
     # - name: certs-configmap
     #   mountPath: /prometheus
+    #   subPath: ""
     #   configMap: certs-configmap
     #   readOnly: true
 
@@ -521,6 +524,7 @@ server:
   extraSecretMounts: []
     # - name: secret-files
     #   mountPath: /etc/secrets
+    #   subPath: ""
     #   secretName: prom-secret-files
     #   readOnly: true