Duplicate label on ConfigMap causes helm install to fail via FluxCD #114
Description
Expected vs actual behavior
Expected: Paralus v0.2.9 is installed via Helm Chart successfully when using FluxCD
Actual: Post-render step and installation fails due to duplicate app.kubernetes.io/component label
Steps to reproduce the bug
- Create a local
kindcluster:kind create cluster - Install Flux on the cluster:
kubectl apply -f https://github.com/fluxcd/flux2/releases/latest/download/install.yaml - Wait for resources to come up in the
flux-systemnamespace - Create barebones
HelmRepositoryandHelmReleaseresources for Flux to install 0.2.9:
---
apiVersion: source.toolkit.fluxcd.io/v1
kind: HelmRepository
metadata:
name: paralus
namespace: flux-system
spec:
interval: 12h0m0s
url: https://paralus.github.io/helm-charts
---
apiVersion: helm.toolkit.fluxcd.io/v2
kind: HelmRelease
metadata:
name: paralus
namespace: flux-system
spec:
releaseName: paralus
chart:
spec:
chart: ztka
reconcileStrategy: ChartVersion
sourceRef:
kind: HelmRepository
name: paralus
version: "0.2.9"
install:
createNamespace: true
interval: 10m0s
targetNamespace: paralus
values:
deploy:
postgresql:
enable: true- Apply both resources against the cluster
- Install fails. View
helmreleaseresource for error:
$ kubectl describe helmrelease paralus
Name: paralus
Namespace: flux-system
Labels: <none>
Annotations: <none>
API Version: helm.toolkit.fluxcd.io/v2
Kind: HelmRelease
Metadata:
Creation Timestamp: 2025-02-19T17:22:24Z
Finalizers:
finalizers.fluxcd.io
Generation: 1
Resource Version: 1544
UID: 5f4065be-555e-46bb-9b42-d200371babf7
Spec:
Chart:
Spec:
Chart: ztka
Reconcile Strategy: ChartVersion
Source Ref:
Kind: HelmRepository
Name: paralus
Version: >=0.2.*
Install:
Create Namespace: true
Interval: 10m0s
Release Name: paralus
Target Namespace: paralus
Values:
Deploy:
Postgresql:
Enable: true
Status:
Conditions:
Last Transition Time: 2025-02-19T17:22:27Z
Message: Running 'install' action with timeout of 5m0s
Observed Generation: 1
Reason: Progressing
Status: True
Type: Reconciling
Last Transition Time: 2025-02-19T17:22:28Z
Message: Helm install failed for release paralus/paralus with chart [email protected]: error while running post render on files: map[string]interface {}(nil): yaml: unmarshal errors:
line 14: mapping key "app.kubernetes.io/component" already defined at line 9
Observed Generation: 1
Reason: InstallFailed
Status: False
Type: Ready
Last Transition Time: 2025-02-19T17:22:27Z
Message: Helm install failed for release paralus/paralus with chart [email protected]: error while running post render on files: map[string]interface {}(nil): yaml: unmarshal errors:
line 14: mapping key "app.kubernetes.io/component" already defined at line 9
Observed Generation: 1
Reason: InstallFailed
Status: False
Type: Released
Failures: 2
Helm Chart: flux-system/flux-system-paralus
Last Attempted Config Digest: sha256:b3d7c5001e0cb84511e487596a464f377bfc51ee3ad6edd87511a351a8ac5317
Last Attempted Generation: 1
Last Attempted Release Action: install
Last Attempted Revision: 0.2.9
Observed Generation: -1
Storage Namespace: flux-system
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Normal HelmChartCreated 4s helm-controller Created HelmChart/flux-system/flux-system-paralus with SourceRef 'HelmRepository/flux-system/paralus'
Warning InstallFailed 2s helm-controller Helm install failed for release paralus/paralus with chart [email protected]: error while running post render on files: map[string]interface {}(nil): yaml: unmarshal errors:
line 14: mapping key "app.kubernetes.io/component" already defined at line 9
Last Helm logs:
2025-02-19T17:22:27.062811632Z: applying CustomResourceDefinition(s) with policy Create
2025-02-19T17:22:27.062813507Z: creating 1 resource(s)
2025-02-19T17:22:27.067431046Z: CustomResourceDefinition contourconfigurations.projectcontour.io is already present. Skipping.
2025-02-19T17:22:27.06743238Z: creating 1 resource(s)
2025-02-19T17:22:27.069853336Z: CustomResourceDefinition extensionservices.projectcontour.io is already present. Skipping.
2025-02-19T17:22:27.069854628Z: creating 1 resource(s)
2025-02-19T17:22:27.07688629Z: CustomResourceDefinition httpproxies.projectcontour.io is already present. Skipping.
2025-02-19T17:22:27.076887582Z: creating 1 resource(s)
2025-02-19T17:22:27.078951955Z: CustomResourceDefinition tlscertificatedelegations.projectcontour.io is already present. Skipping.
Warning InstallFailed 1s helm-controller Helm install failed for release paralus/paralus with chart [email protected]: error while running post render on files: map[string]interface {}(nil): yaml: unmarshal errors:
line 14: mapping key "app.kubernetes.io/component" already defined at line 9Are you using the latest version of the project?
You can check your version by running helm ls|grep '^<deployment-name>' or using pctl, pctl version, and provide the output.
- 0.2.9
What is your environment setup? Please tell us your cloud provider, operating system, and include the output of kubectl version --output=yaml and helm version. Any other information that you have, eg. logs and custom values, is highly appreciated!
kubectl output:
clientVersion:
buildDate: "1980-01-01T00:00:00Z"
compiler: gc
gitCommit: 67a30c0adcf52bd3f56ff0893ce19966be12991f
gitTreeState: archive
gitVersion: v1.32.2
goVersion: go1.23.5
major: "1"
minor: "32"
platform: darwin/arm64
kustomizeVersion: v5.5.0
serverVersion:
buildDate: "2025-01-15T14:32:38Z"
compiler: gc
gitCommit: af64d838aacd9173317b39cf273741816bd82377
gitTreeState: clean
gitVersion: v1.31.5
goVersion: go1.22.10
major: "1"
minor: "31"
platform: linux/amd64
helm output: version.BuildInfo{Version:"v3.16.3", GitCommit:"v3.16.3", GitTreeState:"", GoVersion:"go1.23.3"}
(optional) If you have ideas on why the bug happens or how it can be solved, please provide it here
This is a combination of the changes introduced here. Adding app.kubernetes.io/component: kratos to this include causes a conflict with the app.kubernetes.io/component: configuration label already applied to the kratos-config-hooks ConfigMap here.
Using helm template makes the issue clearer. The generated YAML is invalid :
# Source: ztka/templates/configmap-kratos-hooks.yaml
apiVersion: v1
kind: ConfigMap
metadata:
name: kratos-config-hooks
labels:
helm.sh/chart: ztka-0.2.9
app.kubernetes.io/version: "v0.2.8"
app.kubernetes.io/component: kratos <-- duplicate label
app.kubernetes.io/part-of: paralus
app.kubernetes.io/managed-by: Helm
app.kubernetes.io/name: kratos-config-hooks
app.kubernetes.io/instance: paralus
app.kubernetes.io/component: configuration <-- duplicate labelPassing the output through a YAML linter also flags it up:
$ helm template paralus paralus/ztka --values ./values-test.yaml | yamllint -
stdin
...
364:5 error duplication of key "app.kubernetes.io/component" in mapping (key-duplicates)This isn't caught in a regular helm install because Helm doesn't care about duplicate keys and doesn't validate YAML. Flux's Helm controller however parses and validates YAML, specifically due to using kyaml. Here's a relevant issue in the repo for Flux's helm controller: fluxcd/helm-controller#283.
More to the point, there shouldn't be duplicate keys/invalid YAML at all, and not being able to apply the chart via Flux is a massive pain point.
The fix is very straightforward: remove one of those two labels.
- I've described the bug, included steps to reproduce it, and included my environment setup with all customizations.
- I'm using the latest version of the project.