Feature: Chart should use tpl on values where possible #52
Description
Issue submitter TODO list
- I've looked up my issue in FAQ
- I've searched for an already existing issues here (legacy) and here
- I've tried installing latest charts and the issue still persists there
- I'm running a supported version of the application & chart which is listed here
Describe the bug (actual behavior)
When using the chart as a dependency from another chart (one deploying a Strimzi cluster with a UI for it in my case), it is often useful to template values in the chart's values.yaml.
For this to work, those values need to have the tpl function run on it though, otherwise the template ends up in the output and results in errors when the chart is deployed.
Expected behavior
Using templates in most places in the dependant chart's values.yaml to pass settings to the kafka-ui chart results in errors.
Your installation details
Chart version 1.5.1.
Steps to reproduce
Pass template strings in the values.yaml.
Example:
test-kafka-ui-values.yaml
testBase: test-string
yamlApplicationSecret:
name: '{{ .Values.testBase }}-kafka-ui-config'
key: config.yaml
envs:
secretMappings:
KAFKA_CLUSTERS_0_PROPERTIES_SASL_JAAS_CONFIG:
name: '{{ .Values.testBase }}-kafka-ui'
keyName: sasl.jaas.config
env:
- name: KAFKA_CLUSTERS_0_NAME
value: '{{ .Values.testBase }}'
- name: KAFKA_CLUSTERS_0_BOOTSTRAPSERVERS
value: '{{ .Values.testBase }}-kafka:9092'
- name: KAFKA_CLUSTERS_0_PROPERTIES_SECURITY_PROTOCOL
value: SASL_PLAINTEXT
- name: KAFKA_CLUSTERS_0_PROPERTIES_SASL_MECHANISM
value: SCRAM-SHA-512
- name: KAFKA_CLUSTERS_0_PROPERTIES_PROTOCOL
value: SASL
ingress:
enabled: false
host: render-test.example.com
annotations:
cert-manager.io/cluster-issuer: "letsencrypt-prod"
ingressClassName: "nginx"
tls:
enabled: true
secretName: '{{ .Values.testBase }}-kafka-public-tls'
This will give an error currently: (--debug allows checking the resultant YAML)
helm template test-render charts/kafka-ui -f test-kafka-ui-values.yaml --debug
Screenshots
No response
Logs
For the example:
---
# Source: kafka-ui/templates/serviceaccount.yaml
apiVersion: v1
kind: ServiceAccount
metadata:
name: test-render-kafka-ui
namespace: default
labels:
helm.sh/chart: kafka-ui-1.5.1
app.kubernetes.io/name: kafka-ui
app.kubernetes.io/instance: test-render
app.kubernetes.io/version: "v1.3.0"
app.kubernetes.io/managed-by: Helm
---
# Source: kafka-ui/templates/service.yaml
apiVersion: v1
kind: Service
metadata:
name: test-render-kafka-ui
namespace: default
labels:
helm.sh/chart: kafka-ui-1.5.1
app.kubernetes.io/name: kafka-ui
app.kubernetes.io/instance: test-render
app.kubernetes.io/version: "v1.3.0"
app.kubernetes.io/managed-by: Helm
spec:
type: ClusterIP
ports:
- port: 80
targetPort: http
protocol: TCP
name: http
selector:
app.kubernetes.io/name: kafka-ui
app.kubernetes.io/instance: test-render
---
# Source: kafka-ui/templates/deployment.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
name: test-render-kafka-ui
namespace: default
labels:
helm.sh/chart: kafka-ui-1.5.1
app.kubernetes.io/name: kafka-ui
app.kubernetes.io/instance: test-render
app.kubernetes.io/version: "v1.3.0"
app.kubernetes.io/managed-by: Helm
spec:
replicas: 1
selector:
matchLabels:
app.kubernetes.io/name: kafka-ui
app.kubernetes.io/instance: test-render
template:
metadata:
annotations:
checksum/config: e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855
checksum/configFromValues: 01ba4719c80b6fe911b091a7c05124b64eeece964e09c058ef8f9805daca546b
checksum/secret: 01ba4719c80b6fe911b091a7c05124b64eeece964e09c058ef8f9805daca546b
labels:
app.kubernetes.io/name: kafka-ui
app.kubernetes.io/instance: test-render
spec:
serviceAccountName: test-render-kafka-ui
securityContext:
{}
containers:
- name: kafka-ui
securityContext:
{}
image: ghcr.io/kafbat/kafka-ui:v1.3.0
imagePullPolicy: IfNotPresent
env:
- name: KAFKA_CLUSTERS_0_NAME
value: '{{ .Values.testBase }}'
- name: KAFKA_CLUSTERS_0_BOOTSTRAPSERVERS
value: '{{ .Values.testBase }}-kafka:9092'
- name: KAFKA_CLUSTERS_0_PROPERTIES_SECURITY_PROTOCOL
value: SASL_PLAINTEXT
- name: KAFKA_CLUSTERS_0_PROPERTIES_SASL_MECHANISM
value: SCRAM-SHA-512
- name: KAFKA_CLUSTERS_0_PROPERTIES_PROTOCOL
value: SASL
- name: KAFKA_CLUSTERS_0_PROPERTIES_SASL_JAAS_CONFIG
valueFrom:
secretKeyRef:
name: {{ .Values.testBase }}-kafka-ui
key: sasl.jaas.config
ports:
- name: http
containerPort: 8080
protocol: TCP
livenessProbe:
httpGet:
path: /actuator/health
port: http
initialDelaySeconds: 60
periodSeconds: 30
timeoutSeconds: 10
readinessProbe:
httpGet:
path: /actuator/health
port: http
initialDelaySeconds: 60
periodSeconds: 30
timeoutSeconds: 10
resources:
{}
Error: YAML parse error on kafka-ui/templates/deployment.yaml: error converting YAML to JSON: yaml: line 50: did not find expected key
helm.go:86: 2025-08-29 12:56:12.3143595 +0200 SAST m=+0.163970601 [debug] error converting YAML to JSON: yaml: line 50: did not find expected key
YAML parse error on kafka-ui/templates/deployment.yaml
helm.sh/helm/v3/pkg/releaseutil.(*manifestFile).sort
helm.sh/helm/v3/pkg/releaseutil/manifest_sorter.go:144
helm.sh/helm/v3/pkg/releaseutil.SortManifests
helm.sh/helm/v3/pkg/releaseutil/manifest_sorter.go:104
helm.sh/helm/v3/pkg/action.(*Configuration).renderResources
helm.sh/helm/v3/pkg/action/action.go:168
helm.sh/helm/v3/pkg/action.(*Install).RunWithContext
helm.sh/helm/v3/pkg/action/install.go:316
main.runInstall
helm.sh/helm/v3/cmd/helm/install.go:317
main.newTemplateCmd.func2
helm.sh/helm/v3/cmd/helm/template.go:95
github.com/spf13/cobra.(*Command).execute
github.com/spf13/[email protected]/command.go:985
github.com/spf13/cobra.(*Command).ExecuteC
github.com/spf13/[email protected]/command.go:1117
github.com/spf13/cobra.(*Command).Execute
github.com/spf13/[email protected]/command.go:1041
main.main
helm.sh/helm/v3/cmd/helm/helm.go:85
runtime.main
runtime/proc.go:272
runtime.goexit
runtime/asm_amd64.s:1700
Additional context
#6 templated the config, but it would be useful to have this in many more places.
I want to submit a PR for the parts that affect me, but I think having an issue for this would be useful for others as well.