Add storage for Prometheus using a PersistentVolumeClaim

chart/openfaas/README.md

@@ -680,8 +680,7 @@ For legacy scaling in OpenFaaS Community Edition.
 | ----------------------- | ---------------------------------- | ---------------------------------------------------------- |
 | `alertmanager.create` | Create the AlertManager component | `true` |
 | `alertmanager.image` | Container image used for alertmanager | See [values.yaml](./values.yaml) |
-| `alertmanager.resources` | Resource limits and requests for alertmanager pods | See [values.yaml](./values.
-
+| `alertmanager.resources` | Resource limits and requests for alertmanager pods | See [values.yaml](./values.yaml) |
 
 ### Prometheus (built-in, for autoscaling and metrics)
 
@@ -693,3 +692,8 @@ For legacy scaling in OpenFaaS Community Edition.
 | `prometheus.retention.size` | The maximum number of bytes of storage blocks to retain. Units supported: B, KB, MB, GB, TB, PB, EB. 0 meaning disabled. See: [Prometheus storage](https://prometheus.io/docs/prometheus/latest/storage/#operational-aspects)| `0` |
 | `prometheus.resources` | Resource limits and requests for prometheus containers | See [values.yaml](./values.yaml) |
 | `prometheus.recordingRules` | Custom recording rules for autoscaling. | `[]` |
+| `prometheus.pvc` | Persistent volume claim for Prometheus used so that metrics survive restarts of the Pod and upgrades of the chart | `{}` |
+| `prometheus.pvc.enabled` | Enable persistent volume claim for Prometheus | `false` |
+| `prometheus.pvc.storageClassName` | Storage class for Prometheus PVC, set to `""` for the default/standard class to be picked | `""` |
+| `prometheus.pvc.size` | Size of the Prometheus PVC, 60-100Gi may be a better fit for a busy production environment | `10Gi` |
+| `prometheus.pvc.name` | Name of the Prometheus PVC, required for multiple installations within the same cluster | `""` |

chart/openfaas/templates/prometheus-dep.yaml

@@ -14,6 +14,8 @@ metadata:
  namespace: {{ .Release.Namespace | quote }}
 spec:
  replicas: 1
+ strategy:
+ type: Recreate
  selector:
  matchLabels:
  app: prometheus
@@ -119,8 +121,20 @@ spec:
  path: prometheus-rules.yml
  mode: 0644
 {{- end }}
+
+{{- if and .Values.prometheus.pvc.enabled .Values.openfaasPro }}
+ - name: prom-data
+ persistentVolumeClaim:
+ {{- if .Values.prometheus.pvc.name }}
+ claimName: {{.Values.prometheus.pvc.name}}
+ {{- else }}
+ claimName: prometheus-data
+ {{- end }}
+{{- else }}
  - name: prom-data
  emptyDir: {}
+{{- end }}
+
  {{- with .Values.nodeSelector }}
  nodeSelector:
 {{ toYaml . | indent 8 }}

chart/openfaas/templates/prometheus-pvc.yaml

@@ -0,0 +1,30 @@
+{{- $functionNs := default .Release.Namespace .Values.functionNamespace }}
+{{- if .Values.openfaasPro }}
+{{- if and .Values.prometheus.create .Values.prometheus.pvc.enabled }}
+---
+apiVersion: v1
+kind: PersistentVolumeClaim
+metadata:
+ labels:
+ app: {{ template "openfaas.name" . }}
+ chart: {{ .Chart.Name }}-{{ .Chart.Version }}
+ component: prometheus
+ heritage: {{ .Release.Service }}
+ release: {{ .Release.Name }}
+{{- if .Values.prometheus.pvc.name }}
+ name: {{.Values.prometheus.pvc.name}}
+{{- else }}
+ name: prometheus-data
+{{- end }}
+ namespace: {{ .Release.Namespace | quote }}
+spec:
+ accessModes:
+ - ReadWriteOnce
+ resources:
+ requests:
+ storage: {{ .Values.prometheus.pvc.size | quote }}
+ {{- with .Values.prometheus.pvc.storageClassName }}
+ storageClassName: {{ . | quote }}
+ {{- end }}
+{{- end }}
+{{- end }}

chart/openfaas/values.yaml

@@ -359,6 +359,11 @@ iam:
  url: https://kubernetes.default.svc.cluster.local
  tokenExpiry: 2h
 
+## Prometheus is required for metrics and autoscaling
+##
+## It is bundled into OpenFaaS to be used only as an internal component
+## if you wish to retain the metrics for a longer period, you should
+## scrape this instance from an external Prometheus server
 prometheus:
  image: prom/prometheus:v2.54.0
  create: true
@@ -371,22 +376,19 @@ prometheus:
  annotations: {}
  recordingRules: []
 
-alertmanager:
- image: prom/alertmanager:v0.27.0
- create: true
- resources:
- requests:
- memory: "25Mi"
- cpu: "50m"
- limits:
- memory: "50Mi"
-
-stan:
- # Image used for the NATS Streaming when using the deprecated 
- # support in the Community Edition (CE)
- image: nats-streaming:0.25.6
-
-# NATS (required for async)
+ # Set to true to enable persistent storage for the Prometheus Pod
+ # otherwise, the data will be lost when the Pod is restarted
+ pvc:
+ enabled: false
+ # You may want to set this higher for production, or lower for development/staging.
+ size: 30Gi
+ # Leave the storageClassName blank for the default storage class
+ # using the string "default" does not necessarily mean the default
+ # storage class
+ storageClassName:
+
+## NATS is used for OpenFaaS Pro and is required for:
+## asynchronous invocations, billing & auditing webhooks
 nats:
  channel: "faas-request"
  # Stream replication is set to 1 by default. This is only recommended for development.
@@ -405,6 +407,22 @@ nats:
  memory: "120Mi"
  cpu: "100m"
 
+## alertmanager is only used for OpenFaaS CE
+alertmanager:
+ image: prom/alertmanager:v0.27.0
+ create: true
+ resources:
+ requests:
+ memory: "25Mi"
+ cpu: "50m"
+ limits:
+ memory: "50Mi"
+
+## stan is only used for OpenFaaS CE and will be removed in
+## a fture release, having already been deprecated by the NATS team
+stan:
+ image: nats-streaming:0.25.6
+
 # ingress configuration
 ingress:
  enabled: false