[stable/kube-state-metrics] Support automatic sharding (#20791)

Signed-off-by: Alex Gaganov <alex.gaganov@fiverr.com>

stable/kube-state-metrics/Chart.yaml

@@ -6,7 +6,7 @@ keywords:
 - monitoring
 - prometheus
 - kubernetes
-version: 2.6.4
+version: 2.7.0
 appVersion: 1.9.4
 home: https://github.com/kubernetes/kube-state-metrics/
 sources:

stable/kube-state-metrics/README.md

@@ -18,6 +18,7 @@ $ helm install stable/kube-state-metrics
 | `image.tag`                                  | The image tag to pull from                                                            | `v1.9.4`                                   |
 | `image.pullPolicy`                           | Image pull policy                                                                     | `IfNotPresent`                             |
 | `replicas`                                   | Number of replicas                                                                    | `1`                                        |
+| `autosharding.enabled`                       | Set to `true` to automatically shard data across `replicas` pods. EXPERIMENTAL        | `false`                                    |
 | `service.port`                               | The port of the container                                                             | `8080`                                     |
 | `service.annotations`                        | Annotations to be added to the service                                                | `{}`                                       |
 | `customLabels`                               | Custom labels to apply to service, deployment and pods                                | `{}`                                       |

stable/kube-state-metrics/templates/deployment.yaml

@@ -1,5 +1,9 @@
 apiVersion: apps/v1
+{{- if .Values.autosharding.enabled }}
+kind: StatefulSet
+{{- else }}
 kind: Deployment
+{{- end }}
 metadata:
   name: {{ template "kube-state-metrics.fullname" . }}
   namespace: {{ template "kube-state-metrics.namespace" . }}
@@ -16,6 +20,10 @@ spec:
     matchLabels:
       app.kubernetes.io/name: {{ template "kube-state-metrics.name" . }}
   replicas: {{ .Values.replicas }}
+{{- if .Values.autosharding.enabled }}
+  serviceName: {{ template "kube-state-metrics.fullname" . }}
+  volumeClaimTemplates: []
+{{- end }}
   template:
     metadata:
       labels:
@@ -41,6 +49,17 @@ spec:
     {{- end }}
       containers:
       - name: {{ .Chart.Name }}
+{{- if .Values.autosharding.enabled }}
+        env:
+        - name: POD_NAME
+          valueFrom:
+            fieldRef:
+              fieldPath: metadata.name
+        - name: POD_NAMESPACE
+          valueFrom:
+            fieldRef:
+              fieldPath: metadata.namespace
+{{- end }}
         args:
 {{  if .Values.collectors.certificatesigningrequests  }}
         - --collectors=certificatesigningrequests
@@ -128,6 +147,10 @@ spec:
 {{  end  }}
 {{ if .Values.namespace }}
         - --namespace={{ .Values.namespace }}
+{{ end }}
+{{ if .Values.autosharding.enabled }}
+        - --pod=$(POD_NAME)
+        - --pod-namespace=$(POD_NAMESPACE)
 {{ end }}
         imagePullPolicy: {{ .Values.image.pullPolicy }}
         image: "{{ .Values.image.repository }}:{{ .Values.image.tag }}"

stable/kube-state-metrics/templates/stsdiscovery-role.yaml

@@ -0,0 +1,27 @@
+{{- if and .Values.autosharding.enabled .Values.rbac.create -}}
+apiVersion: rbac.authorization.k8s.io/v1
+kind: Role
+metadata:
+  name: stsdiscovery-{{ template "kube-state-metrics.fullname" . }}
+  namespace: {{ template "kube-state-metrics.namespace" . }}
+  labels:
+    app.kubernetes.io/name: {{ template "kube-state-metrics.name" . }}
+    helm.sh/chart: {{ .Chart.Name }}-{{ .Chart.Version }}
+    app.kubernetes.io/managed-by: {{ .Release.Service }}
+    app.kubernetes.io/instance: {{ .Release.Name }}
+rules:
+- apiGroups:
+  - ""
+  resources:
+  - pods
+  verbs:
+  - get
+- apiGroups:
+  - apps
+  resourceNames:
+  - kube-state-metrics
+  resources:
+  - statefulsets
+  verbs:
+  - get
+{{- end }}

stable/kube-state-metrics/templates/stsdiscovery-rolebinding.yaml

@@ -0,0 +1,20 @@
+{{- if and .Values.autosharding.enabled .Values.rbac.create -}}
+apiVersion: rbac.authorization.k8s.io/v1
+kind: RoleBinding
+metadata:
+  name: stsdiscovery-{{ template "kube-state-metrics.fullname" . }}
+  namespace: {{ template "kube-state-metrics.namespace" . }}
+  labels:
+    app.kubernetes.io/name: {{ template "kube-state-metrics.name" . }}
+    helm.sh/chart: {{ .Chart.Name }}-{{ .Chart.Version }}
+    app.kubernetes.io/managed-by: {{ .Release.Service }}
+    app.kubernetes.io/instance: {{ .Release.Name }}
+roleRef:
+  apiGroup: rbac.authorization.k8s.io
+  kind: Role
+  name: stsdiscovery-{{ template "kube-state-metrics.fullname" . }}
+subjects:
+  - kind: ServiceAccount
+    name: {{ template "kube-state-metrics.fullname" . }}
+    namespace: {{ template "kube-state-metrics.namespace" . }}
+{{- end }}

stable/kube-state-metrics/values.yaml

@@ -5,6 +5,13 @@ image:
   tag: v1.9.4
   pullPolicy: IfNotPresent
 
+# If set to true, this will deploy kube-state-metrics as a StatefulSet and the data
+# will be automatically sharded across <.Values.replicas> pods using the built-in
+# autodiscovery feature: https://github.com/kubernetes/kube-state-metrics#automated-sharding
+# This is an experimental feature and there are no stability guarantees.
+autosharding:
+  enabled: false
+
 replicas: 1
 
 service: