<p>The task is to range over workers collection and if the current worker has autoscaling.enabled=true create an hpa for it.</p>

<p>I've tried to compare .autoscaling.enabled to "true" but it returned "error calling eq: incompatible types for comparison". <a href="https://github.com/helm/helm/issues/2979" rel="nofollow noreferrer">Here</a> people say that it actually means that .autoscaling.enabled is nil. So {{ if .autoscaling.enabled }} somehow doesn't see the variable and assumes it doesn't exist.</p>

<p>Values:</p>

<pre><code>...
workers:
  - name: worker1
    command: somecommand1
    memoryRequest: 500Mi
    memoryLimit: 1400Mi
    cpuRequest: 50m
    cpuLimit: 150m
    autoscaling:
      enabled: false
  - name: worker2
    command: somecommand2
    memoryRequest: 512Mi
    memoryLimit: 1300Mi
    cpuRequest: 50m
    cpuLimit: 150m
    autoscaling:
      enabled: false
  - name: workerWithAutoscaling
    command: somecommand3
    memoryRequest: 600Mi
    memoryLimit: 2048Mi
    cpuRequest: 150m
    cpuLimit: 400m
    autoscaling:
      enabled: true
      minReplicas: 1
      maxReplicas: 5
      targetCPUUtilization: 50
      targetMemoryUtilization: 50
...
</code></pre>

<p>template:</p>

<pre><code>...
{{- range .Values.workers }}
{{- if .autoscaling.enabled }}
apiVersion: autoscaling/v2beta1
kind: HorizontalPodAutoscaler
metadata:
  labels:
    ...
  name: "hpa-{{ .name }}-{{ $.Realeas.Name }}"
spec:
  scaleTargetRef:
    apiVersion: apps/v1
    kind: Deployment
    name: {{ .name }}
  minReplicas: {{ .minReplicas }}
  maxReplicas: {{ .maxReplicas }}
  metrics:
{{- with .targetCPUUtilization}}
    - type: Resource
      resource:
        name: cpu
        targetAverageUtilization: {{ . }}
{{- end }}
{{- with .targetMemoryUtilization}}
    - type: Resource
      resource:
        name: memory
        targetAverageUtilization: {{ . }}
{{- end }}
---
{{- end }}
{{- end }}
</code></pre>

<p>I expect the manifest for one hpa that targets workerWithAutoscaling, but the actual output is totally empty.</p>

<p>Your use of <code>{{- range .Values.workers }}</code> and <code>{{- if .autoscaling.enabled }}</code> is fine. You are not getting any values because <code>.minReplicas</code>, <code>.maxReplicas</code>, etc, are inside <code>.autoscaling</code> scope. </p>

<p>See <a href="https://github.com/helm/helm/blob/master/docs/chart_template_guide/control_structures.md#modifying-scope-using-with" rel="nofollow noreferrer">Modifying scope using <code>with</code></a></p>

<p>Adding <code>{{- with .autoscaling}}</code> will solve the issue.</p>

<pre><code>{{- range .Values.workers }}
{{- if .autoscaling.enabled }}
apiVersion: autoscaling/v2beta1
kind: HorizontalPodAutoscaler
metadata:
  labels:
  name: "hpa-{{ .name }}-{{ $.Release.Name }}"
spec:
  scaleTargetRef:
    apiVersion: apps/v1
    kind: Deployment
    name: {{ .name }}
{{- with .autoscaling}}
  minReplicas: {{ .minReplicas }}
  maxReplicas: {{ .maxReplicas }}
  metrics:
    - type: Resource
      resource:
        name: cpu
        targetAverageUtilization: {{ .targetCPUUtilization}}
    - type: Resource
      resource:
        name: memory
        targetAverageUtilization: {{ .targetMemoryUtilization}}
{{- end }}
{{- end }}
{{- end }}
</code></pre>

<p><code>helm template .</code></p>

<pre><code>---
# Source: templates/hpa.yaml

apiVersion: autoscaling/v2beta1
kind: HorizontalPodAutoscaler
metadata:
  labels:
  name: "hpa-workerWithAutoscaling-release-name"
spec:
  scaleTargetRef:
    apiVersion: apps/v1
    kind: Deployment
    name: workerWithAutoscaling
  minReplicas: 1
  maxReplicas: 5
  metrics:
    - type: Resource
      resource:
        name: cpu
        targetAverageUtilization: 50
    - type: Resource
      resource:
        name: memory
        targetAverageUtilization: 50
</code></pre>
