iterate though complex values.yaml using range in helm chart

Question

I'm new here to helm world. I want to generate manifest from my values and sample.yaml so I trying to create a template from my sample.yaml files.

Values.yaml

prodapps:
 alpha:
   name: alpha
   image: alpha.azurecr.io/alpha:latest
   imagePullPolicy: IfNotPresent
   resources:
     requests:
       memory: "10000Mi"
       cpu: "150m"
     limits:
       memory: "800Mi"
       cpu: 600m"
   ingress:
     enabled: true
     annotations:
       zap.ingress.kubernetes.io/rule-type: PathPrefixStrip
       nginx.ingress.kubernetes.io/rewrite-target: /
     path: /alpha/api
     hosts:
       - demo.jumboapps.com
 beta:
   name: beta
   disable: true
   image: beta.azurecr.io/beta:latest
   imagePullPolicy: IfNotPresent
   resources:
     requests:
       memory: "10000Mi"
       cpu: "150m"
     limits:
       memory: "800Mi"
       cpu: 600m"
   ingress:
     enabled: true
     annotations:
       zap.ingress.kubernetes.io/rule-type: PathPrefixStrip
       nginx.ingress.kubernetes.io/rewrite-target: /
     path: /beta/api
     hosts:
       - demo.jumboapps.com

Sample.yaml

apiVersion: v1
kind: Service
metadata:
 name: "{{ .Values.prodapps.alpha.name }}-svc"
 namespace: "{{ .Release.Namespace }}"
spec:
 ports:
   - port: 80
     name: "http"
 selector:
   app: "{{ .Values.prodapps.alpha.name }}"
---
apiVersion: v1
kind: Service
metadata:
 name: "{{ .Values.prodapps.beta.name }}-svc"
 namespace: "{{ .Release.Namespace }}"
spec:
 ports:
   - port: 80
     name: "http"
 selector:
   app: "{{ .Values.prodapps.beta.name }}"

My main goal is to templatize my sample.yaml.by and produce the valid Manifet file. following helm documentation. But I cant find any sensible(my understandable) syntax for looping through complex values files.

Please anyone help me out with this.

It doesn't really make sense to include every possible setting in Helm values; it would be simpler and clearer to directly write them in standard Kubernetes YAML files. If you need to iterate through `.Values` you can use the [text/template](https://pkg.go.dev/text/template) `range` function. From what you've shown, though, it's not totally clear what problem you're running into. — David Maze, Aug 22 '21 at 14:26
@DavidMaze , Is there any globalised/standard procedure to construct .Values.yaml file.If yes , can you please help me out with that. — praveen, Aug 23 '21 at 02:53

score 0 · Accepted Answer · answered Aug 23 '21 at 03:03

You need to learn more about the usage of range and how k8s divides resources with '---' when applying resources.

You can imitate the following

Values.yaml

prodapps:
  alpha:
    name: alpha
    image: alpha.azurecr.io/alpha:latest
    imagePullPolicy: IfNotPresent
    resources:
      requests:
        memory: "10000Mi"
        cpu: "150m"
      limits:
        memory: "800Mi"
        cpu: 600m"
  beta:
    name: beta
    disable: true
    image: beta.azurecr.io/beta:latest
    imagePullPolicy: IfNotPresent
    resources:
      requests:
        memory: "10000Mi"
        cpu: "150m"
      limits:
        memory: "800Mi"
        cpu: 600m"

service.yaml

{{ if .Values.prodapps }}
{{- range $k, $v := $.Values.prodapps }}
---
apiVersion: v1
kind: Service
metadata:
  name: "{{ $v.name }}-svc"
  namespace: "{{ .Release.Namespace }}"
spec:
  ports:
    - port: 80
      name: "http"
  selector:
    app: "{{ $v.name }}"
{{- end }}
{{- end }}

deployment.yaml

{{ if .Values.prodapps }}
{{- range $k, $v := $.Values.prodapps }}
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: "{{ $v.name }}-dep"
  namespace: "{{ .Release.Namespace }}"
spec:
  template:
    spec:
      containers:
        - name: {{ $v.Name }}
          image: "{{ $v.image }}"
          imagePullPolicy: {{ $v.imagePullPolicy }}
          resources:
            {{- toYaml $v.resources | nindent 12 }}
{{- end }}
{{- end }}

iterate though complex values.yaml using range in helm chart

1 Answers1