Switch Loki to StatefulSet (grafana#585)

Signed-off-by: Steven Sheehy <ssheehy@firescope.com>

production/helm/README.md

@@ -105,20 +105,17 @@ tls:
 
 ## How to contribute
 
-If you want to add any feature to helm chart, you can follow as below:
+After adding your new feature to the appropriate chart, you can build and deploy it locally to test:
 
 ```bash
-$ # do some changes to loki/promtail in the corresponding directory
 $ make helm
 $ helm upgrade --install loki ./loki-stack-*.tgz
 ```
 
-After verify changes, need to bump chart version.
-For example, if you update the loki chart, you need to bump the version as following:
+After verifying your changes, you need to bump the chart version following [semantic versioning](https://semver.org) rules.
+For example, if you update the loki chart, you need to bump the versions as follows:
 
-```bash
-$ # update version loki/Chart.yaml
-$ # update version loki-stack/Chart.yaml
-```
+- Update version loki/Chart.yaml
+- Update version loki-stack/Chart.yaml
 
 You can use the `make helm-debug` to test and print out all chart templates. If you want to install helm (tiller) in your cluster use `make helm-install`, to install the current build in your Kubernetes cluster run `make helm-upgrade`.

production/helm/loki-stack/Chart.yaml

@@ -1,5 +1,5 @@
 name: loki-stack
-version: 0.9.5
+version: 0.10.0
 appVersion: 0.0.1
 kubeVersion: "^1.10.0-0"
 description: "Loki: like Prometheus, but for logs."

production/helm/loki/Chart.yaml

@@ -1,5 +1,5 @@
 name: loki
-version: 0.8.5
+version: 0.9.0
 appVersion: 0.0.1
 kubeVersion: "^1.10.0-0"
 description: "Loki: like Prometheus, but for logs."

production/helm/loki/templates/service-headless.yaml

@@ -0,0 +1,19 @@
+apiVersion: v1
+kind: Service
+metadata:
+  name: {{ template "loki.fullname" . }}-headless
+  labels:
+    app: {{ template "loki.name" . }}
+    chart: {{ template "loki.chart" . }}
+    release: {{ .Release.Name }}
+    heritage: {{ .Release.Service }}
+spec:
+  clusterIP: None
+  ports:
+    - port: {{ .Values.service.port }}
+      protocol: TCP
+      name: http-metrics
+      targetPort: http-metrics
+  selector:
+    app: {{ template "loki.name" . }}
+    release: {{ .Release.Name }}

production/helm/loki/templates/deployment.yaml → production/helm/loki/templates/statefulset.yaml

@@ -1,5 +1,5 @@
 apiVersion: apps/v1
-kind: Deployment
+kind: StatefulSet
 metadata:
   name: {{ template "loki.fullname" . }}
   labels:
@@ -10,17 +10,15 @@ metadata:
   annotations:
     {{- toYaml .Values.annotations | nindent 4 }}
 spec:
+  podManagementPolicy: {{ .Values.podManagementPolicy }}
   replicas: {{ .Values.replicas }}
-  minReadySeconds: {{ .Values.minReadySeconds }}
   selector:
     matchLabels:
       app: {{ template "loki.name" . }}
       release: {{ .Release.Name }}
-  strategy:
-    type: {{ .Values.deploymentStrategy }}
-  {{- if ne .Values.deploymentStrategy "RollingUpdate" }}
-    rollingUpdate: null
-  {{- end }}
+  serviceName: {{ template "loki.fullname" . }}-headless
+  updateStrategy:
+    {{- toYaml .Values.updateStrategy | nindent 4 }}
   template:
     metadata:
       labels:
@@ -29,7 +27,7 @@ spec:
         release: {{ .Release.Name }}
         {{- with .Values.podLabels }}
         {{- toYaml . | nindent 8 }}
-        {{- end }}  
+        {{- end }}
       annotations:
         checksum/config: {{ include (print $.Template.BasePath "/secret.yaml") . | sha256sum }}
         {{- with .Values.podAnnotations }}
@@ -50,7 +48,7 @@ spec:
             - "-config.file=/etc/loki/loki.yaml"
           {{- range $key, $value := .Values.extraArgs }}
             - "-{{ $key }}={{ $value }}"
-          {{- end }}            
+          {{- end }}
           volumeMounts:
             - name: config
               mountPath: /etc/loki
@@ -85,11 +83,25 @@ spec:
         - name: config
           secret:
             secretName: {{ template "loki.fullname" . }}
+  {{- if not .Values.persistence.enabled }}
         - name: storage
-      {{- if .Values.persistence.enabled }}
-          persistentVolumeClaim:
-            claimName: {{ .Values.persistence.existingClaim | default (include "loki.fullname" .) }}
-      {{- else }}
           emptyDir: {}
-      {{- end }}
+  {{- else if .Values.persistence.existingClaim }}
+        - name: storage
+          persistentVolumeClaim:
+            claimName: {{ .Values.persistence.existingClaim }}
+  {{- else }}
+  volumeClaimTemplates:
+  - metadata:
+      name: storage
+      annotations:
+        {{- toYaml .Values.persistence.annotations | nindent 8 }}
+    spec:
+      accessModes:
+        {{- toYaml .Values.persistence.accessModes | nindent 8 }}
+      resources:
+        requests:
+          storage: {{ .Values.persistence.size | quote }}
+      storageClassName: {{ .Values.persistence.storageClassName }}
+  {{- end }}
 

production/helm/loki/values.yaml

@@ -11,7 +11,7 @@ affinity: {}
 #         - loki
 #     topologyKey: "kubernetes.io/hostname"
 
-## Deployment annotations
+## StatefulSet annotations
 annotations: {}
 
 # enable tracing for debug, need install jaeger and specify right jaeger_agent_host
@@ -20,7 +20,6 @@ tracing:
 
 config:
   auth_enabled: false
-
   ingester:
     chunk_idle_period: 15m
     chunk_block_size: 262144
@@ -63,8 +62,6 @@ config:
     retention_deletes_enabled: false
     retention_period: 0
 
-deploymentStrategy: RollingUpdate
-
 image:
   repository: grafana/loki
   tag: latest
@@ -80,8 +77,6 @@ livenessProbe:
     port: http-metrics
   initialDelaySeconds: 45
 
-minReadySeconds: 0
-
 ## Enable persistence using Persistent Volume Claims
 networkPolicy:
   enabled: false
@@ -111,6 +106,8 @@ podAnnotations:
  prometheus.io/scrape: "true"
  prometheus.io/port: "http-metrics"
 
+podManagementPolicy: OrderedReady
+
 ## Assign a PriorityClassName to pods if set
 # priorityClassName:
 
@@ -162,3 +159,6 @@ tolerations: []
 podDisruptionBudget: {}
 # minAvailable: 1
 # maxUnavailable: 1
+
+updateStrategy:
+  type: RollingUpdate