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

Per AI Blitz Plan §6. Layer: 1-T.

Coding Guidelines — ArgoCD Application Manifests

Conventions for ArgoCD Application YAML files in incubator/<env>/.

---

Required fields

Every incubator Application must have all of these:

apiVersion: argoproj.io/v1alpha1
kind: Application
metadata:
  name: incubator-infra-<cluster>       # Must match filename without .yaml
  namespace: <argocd-namespace>         # argocd-prd | argocd-dev | argocd-shared-int
  finalizers:
    - resources-finalizer.argocd.argoproj.io
spec:
  project: default
  source:
    repoURL: 'https://github.com/Meesho/devops-infra-argo-config'
    targetRevision: <branch>            # main | develop | pre-prod
    path: generic-argo-apps-chart
    helm:
      valueFiles:
      - ../values/<env>/incubator-infra-<cluster>-values.yaml
  destination:
    name: in-cluster
    namespace: <argocd-namespace>

---

metadata.name rules

• Must equal the filename without .yaml — this is ArgoCD's tracking key (R9).
• Convention: incubator-infra-<gke-cluster-name> (e.g. incubator-infra-k8s-central-prd-ase1).
• Changing this after the Application is registered breaks ArgoCD tracking; treat as immutable.

---

metadata.namespace (ArgoCD namespace)

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

The metadata.namespace and spec.destination.namespace must be the same value.

---

spec.source.repoURL allow-list

Only one value is permitted:

https://github.com/Meesho/devops-infra-argo-config

Changing this is a Layer 3 operation. See AGENT_BOUNDARIES.md.

---

spec.source.targetRevision

Must match the environment branch:

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

Never pin to a feature branch. Feature branches are not monitored by auto-sync.

---

spec.source.path

Always generic-argo-apps-chart. This is the Helm chart that renders child Applications from the values file.

---

spec.destination.name

Always in-cluster. Incubator Applications run on the ArgoCD admin cluster itself, not on the target GKE cluster.

---

spec.destination.namespace

Must match metadata.namespace — same ArgoCD namespace.

---

Finalizer

The finalizer resources-finalizer.argocd.argoproj.io must be present. It causes ArgoCD to cascade-delete child Applications when the parent incubator is deleted. Removing it creates orphaned child Applications.

---

helm.valueFiles path convention

Paths are relative to the chart root (generic-argo-apps-chart/), so .. is required to reach the repo root:

generic-argo-apps-chart/  (chart root = ArgoCD's working dir for this source)
    ../values/<env>/incubator-infra-<cluster>-values.yaml
         └── resolves to: values/<env>/incubator-infra-<cluster>-values.yaml at repo root

---

Naming invariant

Directory and values path vary by env — but the invariant itself is universal:

prd (main):
  Filename:        incubator/prd/incubator-infra-k8s-central-prd-ase1.yaml
  metadata.name:                 incubator-infra-k8s-central-prd-ase1
  helm.valueFiles: ../values/prd/incubator-infra-k8s-central-prd-ase1-values.yaml

stg (develop):
  Filename:        incubator/infra/incubator-infra-k8s-central-stg-ase1.yaml
  metadata.name:                  incubator-infra-k8s-central-stg-ase1
  helm.valueFiles: ../values/dev/ incubator-infra-k8s-central-stg-ase1-values.yaml

All three must be consistent. Any mismatch causes a routing failure.