Prometheus rule support

2020-10-14 13:36:39 +02:00
parent 8360d3f492
commit 1f10a80af0
9 changed files with 135 additions and 5 deletions
@@ -4,7 +4,7 @@ metadata:
  name: {{ .Release.Name }}
  namespace: {{ .Release.Namespace }}
  labels:
-    {{ include "helm-chart.labels" . | nindent 4 }}
+    {{- include "helm-chart.labels" . | nindent 4 }}
 spec:
  schedule: {{ .Values.schedule | quote }}
  successfulJobsHistoryLimit: 1
@@ -1,4 +1,4 @@
-suite: test deployment
+suite: test cron job
 templates:
  - cronJob.yaml
  - configmap.yaml
@@ -15,4 +15,4 @@ type: application
 # This is the chart version. This version number should be incremented each time you make changes
 # to the chart and its templates, including the app version.
 # Versions are expected to follow Semantic Versioning (https://semver.org/)
-version: 0.5.1
+version: 0.6.0
@@ -0,0 +1,24 @@
+{{- if .Values.prometheusRules }}
+apiVersion: monitoring.coreos.com/v1
+kind: PrometheusRule
+metadata:
+  name: {{ .Release.Name }}
+  namespace: {{ .Release.Namespace }}
+  labels:
+    {{- include "helm-chart.labels" . | nindent 4 }}
+annotations:
+spec:
+  groups:
+    - name: kubernetes-apps
+      rules:
+        {{- range $rule := .Values.prometheusRules }}
+        - alert: {{ $rule.name }}
+          annotations:
+            message: {{ $rule.message | quote }}
+            runbook_url: {{ $rule.runBookURL | quote }}
+          expr: {{ $rule.expression | quote }}
+          for: {{ $rule.for | quote }}
+          labels:
+            {{- toYaml $rule.labels | nindent 12 }}
+        {{- end }}
+{{- end }}
@@ -0,0 +1,24 @@
+suite: test prometheus rule
+templates:
+  - prometheus-rule.yaml
+tests:
+  - it: Should set rules
+    set:
+      prometheusRules:
+        - name: KubePodCrashLooping
+          message: Pod {{`{{`}} $labels.namespace {{`}}`}}/{{`{{`}} $labels.pod {{`}}`}} ({{`{{`}} $labels.container {{`}}`}}) is restarting {{`{{`}} printf "%.2f" $value {{`}}`}} times / 5 minutes.
+          runBookURL:
+          expression: rate(kube_pod_container_status_restarts_total{job="kube-state-metrics", namespace=~"{{ $targetNamespace }}"}[15m]) * 60 * 5 > 0
+          for: 1h
+          labels:
+            severity: criticalv
+    asserts:
+      - equal:
+          path: spec.groups[0].name
+          value: kubernetes-apps
+      - equal:
+          path: spec.groups[0].rules[0].alert
+          value: KubePodCrashLooping
+      - equal:
+          path: spec.groups[0].rules[0].expr
+          value: rate(kube_pod_container_status_restarts_total{job="kube-state-metrics", namespace=~"{{ $targetNamespace }}"}[15m]) * 60 * 5 > 0
@@ -22,7 +22,7 @@ image:
 ingress:
  annotations:
    kubernetes.io/ingress.class: nginx
-  host: chart-example.local
+  host: my-release.mycompany.com
 EOF

 helm template my-release onechart/onechart -f values.yaml
@@ -0,0 +1,53 @@
+Feature branch deploys in large part is a templating question:
+
+- Names should be unique to avoid collision between application instances
+- Names should follow some convention
+- It's driven by CI, and git branch name is a typical input parameter
+
+### Avoiding name collisions
+
+With OneChart, you can drive the naming of most resources by setting a unique release name.
+Release name is unique in Helm too, so it makes it a good tool to drive resource names.
+
+One good practice can be to add a `-$BRANCH` suffix to the feature branch instance:
+
+```
+helm template my-release-my-branch onechart/onechart -f values.yaml
+```
+
+### Avoiding domain name collision
+
+The release name will make all Kubernetes objects unique, but the domain name configuration remains static:
+
+```
+image:
+  repository: nginx
+  tag: 1.19.3
+
+ingress:
+  annotations:
+    kubernetes.io/ingress.class: nginx
+  host: my-release.mycompany.com
+
+helm template my-release-my-branch onechart/onechart -f values.yaml
+```
+
+The `ingress.host` name should also be dynamic to avoid the collision:
+
+```
+helm template my-release-my-branch onechart/onechart\
+  -f values.yaml \
+  --set ingress.host=my-release-my-branch.mycompany.com
+```
+
+### CI
+
+In CI the above command needs to be templated:
+
+```
+helm template my-release-$BRANCH onechart/onechart\
+  -f values.yaml \
+  --set ingress.host=my-release-$BRANCH.mycompany.com
+```
+
+where $BRANCH is a built-in CI variable.
@@ -0,0 +1,27 @@
+This page shows how you can add a `PrometheusRule` to your app deployment.
+
+!!! Note
+    This is a feature only supported by the [kube-stack-prometheus stack (formerly known as the Prometheus Operator)](https://github.com/prometheus-operator/kube-prometheus)
+    
+The following Prometheus rule alerts if a pod is crashlooping:
+
+```yaml
+image:
+  repository: nginx
+  tag: 1.19.3
+
+prometheusRules:
+  - name: KubePodCrashLooping
+    message: "Pod {{`{{`}} $labels.namespace {{`}}`}}/{{`{{`}} $labels.pod {{`}}`}} ({{`{{`}} $labels.container {{`}}`}}) is restarting {{`{{`}} printf \"%.2f\" $value {{`}}`}} times / 5 minutes."
+    runBookURL: myrunbook.com
+    expression: "rate(kube_pod_container_status_restarts_total{job=\"kube-state-metrics\", namespace=~\"{{ $targetNamespace }}\"}[15m]) * 60 * 5 > 0"
+    for: 1h
+    labels:
+      severity: critical
+```
+
+Check the Kubernetes manifest:
+
+```bash
+helm template my-release onechart/onechart -f values.yaml
+```
@@ -28,7 +28,7 @@ site_description: >-
 # Repository
 repo_name: onechart/onechart
 repo_url: https://github.com/onechart/onechart
-edit_uri: https://github.com/onechart/onechart/website
+edit_uri: https://github.com/onechart/onechart/tree/master/website/docs

 extra_css:
  - stylesheets/extra.css
@@ -138,3 +138,5 @@ nav:
      - Volumes: examples/volumes.md
      - Custom command: examples/custom-command.md
      - Cron job: examples/cron-job.md
+      - Feature branch deploys: examples/feature-branch-deploys.md
+      - Prometheus monitoring rules: examples/prometheus-monitoring-rules.md