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kubernetes-helm

Helm Charts - can you dynamically generate n StatefulSets?

I have an application that requires a configurable number of master nodes and replicas. Is there any way to dynamically generate a n stateful sets where n is the number of master nodes I have? The number of master nodes is currently set in values.yaml.

Solution

  • Yes, it is possible with until function.

    values.yaml:

    masterCount: 5

    templates/statefulset.yaml:

    {{ range $k, $v := until ( .Values.masterCount | int) }}
---
apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: nginx-{{ $v }}
spec:
  serviceName: "nginx-{{ $v }}"
  replicas: 3
  selector:
    matchLabels:
      app: nginx-{{ $v }}
  template:
    metadata:
      labels:
        app: nginx-{{ $v }}
    spec:
      containers:
      - name: nginx
        image: k8s.gcr.io/nginx-slim:0.8
        ports:
        - containerPort: 80
          name: web
        volumeMounts:
        - name: www
          mountPath: /usr/share/nginx/html
{{ end }}