[stable/prometheus] Use volumeMount subPath to fix prometheus-server from crashing (#424)

* Use volumeMount subPath to fix prometheus-server from crashing

* Added persistence.subPath options to server and alertmanager that default to ""

* Fixed variable names in templates.

stable/prometheus/Chart.yaml

@@ -1,5 +1,5 @@
 name: prometheus
-version: 2.0.1
+version: 2.0.2
 description: A Prometheus Helm chart for Kubernetes. Prometheus is a monitoring system and time series database.
 home: https://prometheus.io/
 sources:

stable/prometheus/README.md

@@ -57,6 +57,7 @@ The following tables lists the configurable parameters of the Prometheus chart a
 | `alertmanager.persistentVolume.existingClaim` | AlertManager data Persistent Volume existing claim name | |
 | `alertmanager.persistentVolume.size` | AlertManager data Persistent Volume size | `2Gi` |
 | `alertmanager.persistentVolume.storageClass` | AlertManager data Persistent Volume Storage Class | `volume.alpha.kubernetes.io/storage-class: default` |
+| `alertmanager.persistentVolume.subPath` | Subdirectory of the volume to mount at  | `""` |
 | `alertmanager.resources` | Alertmanager resource requests and limits (YAML) |`requests: {cpu: 10m, memory: 32Mi}` |
 | `alertmanager.serviceType` | Alertmanager service type | `ClusterIP` |
 | `alertmanager.storagePath` | Alertmanager data storage path | `/data` |
@@ -85,6 +86,7 @@ The following tables lists the configurable parameters of the Prometheus chart a
 | `server.persistentVolume.existingClaim` | Server data Persistent Volume existing claim name | |
 | `server.persistentVolume.size` | Server data Persistent Volume size | `8Gi` |
 | `server.persistentVolume.storageClass` | Server data Persistent Volume Storage Class | `volume.alpha.kubernetes.io/storage-class: default` |
+| `server.persistentVolume.subPath` | Subdirectory of the volume to mount at  | `""` |
 | `server.resources` | Server resource requests and limits | `requests: {cpu: 500m, memory: 512Mi}` |
 | `server.serviceType` | Server service type | `ClusterIP` |
 | `server.storageLocalPath` | Server local data storage path | `/data` |

stable/prometheus/templates/alertmanager-deployment.yaml

@@ -39,6 +39,7 @@ spec:
               mountPath: /etc/config
             - name: storage-volume
               mountPath: {{ default "/data" .Values.alertmanager.storagePath | quote }}
+              subPath: {{ .Values.alertmanager.persistentVolume.subPath }}
         - name: {{ template "name" . }}-{{ .Values.alertmanager.name }}-{{ .Values.configmapReload.name }}
           image: "{{ .Values.configmapReload.image }}"
           imagePullPolicy: {{ default "" .Values.imagePullPolicy | quote }}

stable/prometheus/templates/server-deployment.yaml

@@ -59,6 +59,7 @@ spec:
               mountPath: /etc/config
             - name: storage-volume
               mountPath: {{ default "/data" .Values.server.storageLocalPath | quote }}
+              subPath: {{ .Values.server.persistentVolume.subPath }}
       terminationGracePeriodSeconds: {{ default 300 .Values.server.terminationGracePeriodSeconds }}
       volumes:
         - name: config-volume

stable/prometheus/values.yaml

@@ -72,6 +72,11 @@ alertmanager:
     ## Default: volume.alpha.kubernetes.io/storage-class: default
     ##
     # storageClass:
+    
+    ## Subdirectory of the volume to mount at
+    ## Useful if the volume's root directory is not empty
+    ## 
+    subPath: ""
 
   ## Alertmanager resource requests and limits
   ## Ref: http://kubernetes.io/docs/user-guide/compute-resources/
@@ -227,6 +232,11 @@ server:
     ## Default: volume.alpha.kubernetes.io/storage-class: default
     ##
     # storageClass:
+    
+    ## Subdirectory of the volume to mount at
+    ## Useful if the volume's root directory is not empty
+    ## 
+    subPath: ""
 
   ## Server resource requests and limits
   ## Ref: http://kubernetes.io/docs/user-guide/compute-resources/