devops-infra-argo-config-gcp/docs/global/coding-guidelines/helm.md

Per AI Blitz Plan §6. Layer: 1-T.

Coding Guidelines — Helm Values Files

Conventions for cluster values files (values/<env>/incubator-infra-<cluster>-values.yaml).

---

File naming

values/<values-dir>/incubator-infra-<gke-cluster-name>-values.yaml

The values directory name does not always match the environment name:

Environment	Branch	Values dir	Example
prd	main	values/prd/	values/prd/incubator-infra-k8s-central-prd-ase1-values.yaml
stg	develop	values/dev/	values/dev/incubator-infra-k8s-central-stg-ase1-values.yaml
dev	develop	values/dev/	values/dev/incubator-infra-k8s-central-dev-ase1-values.yaml
int	pre-prod	values/int/	values/int/incubator-infra-k8s-shared-int-ase1-values.yaml
admin	main / pre-prod	values/admin/	values/admin/incubator-infra-k8s-devops-admin-ase1-values.yaml

Note: stg and dev clusters both live under values/dev/ on the develop branch.

---

Top-level structure

Four keys in this exact order — no additions, no reordering:

clusterSpec:
argocdSpec:
teamSpec:
appSpec:

---

clusterSpec

clusterSpec:
  destination:
    server: ""                          # Always empty string — name-based routing only
    name: "k8s-central-prd-ase1"        # Must match GKE cluster name and helm-overrides/ folder

• server is always "". Never set a URL here.
• name is immutable after cluster registration. Changing it redirects all tooling.

---

argocdSpec

argocdSpec:
  namespace: argocd-prd                 # argocd-prd | argocd-dev | argocd-shared-int

Environment	Namespace
prd	argocd-prd
stg / dev	argocd-dev
int	argocd-shared-int

---

teamSpec

teamSpec:
  devops:
    source:
      repoURL: https://github.com/Meesho/devops-infra-helm-charts
      targetRevision: main              # main | develop | pre-prod
      path: helm-templates
      valueFiles: ../../helm-overrides/<cluster>
    labels:
      bu: infra
      team: devops
      env: prd                          # prd | stg | dev | int | admin
      cluster: k8s-central-prd-ase1    # Must match clusterSpec.destination.name

repoURL allow-list: Only https://github.com/Meesho/devops-infra-helm-charts is permitted.

targetRevision must match the environment:

Environment	targetRevision
prd	main
stg / dev	develop
int	pre-prod

valueFiles path: Relative from helm-templates/ root (two levels up) to the cluster's override directory. Always ../../helm-overrides/<cluster>.

labels.cluster must equal clusterSpec.destination.name exactly — it is used in Application name generation.

---

appSpec

appSpec:
  - name: keda                          # Short, lowercase, hyphen-separated tool name
    namespace: keda-central-prd         # Target K8s namespace
    chartDir: keda                      # Directory under helm-templates/ in helm-charts repo
    valuesDir: keda                     # Directory under helm-overrides/<cluster>/ in helm-charts repo

• One entry = one ArgoCD child Application.
• Generated name: <name>-<mungedCluster>-<env> (e.g. keda-central-prd).
• chartDir and valuesDir must exist in devops-infra-helm-charts before adding the entry (R3).

Optional fields

  - name: coredns
    namespace: kube-system
    chartDir: coredns
    valuesDir: coredns
    nameOverride: coredns-central-prd   # Only for name collisions or >253 char names (R7)
    additionalValueFiles:
      - ../../helm-templates/coredns/gcp-ase1a-values.yaml

---

Common mistakes

Mistake	Impact	Fix
server: <url> instead of ""	May route to wrong cluster	Always use ""
Wrong targetRevision for env	Tools pull from wrong chart branch	Use main/develop/pre-prod per env
chartDir not in helm-templates/	ArgoCD render failure	Verify in devops-infra-helm-charts first
valuesDir missing custom-values.yaml	ArgoCD render failure	Add custom-values.yaml to the override dir
labels.cluster ≠ clusterSpec.destination.name	Application name munging uses wrong cluster	Keep them identical
Duplicate name in appSpec	Application name collision	Use nameOverride for multi-instance tools