LAB 04 – Helm, Kustomize and multiple sources¶

Story: The web shop needs a dev and a prod environment from one set of manifests, and the public status page should come from the vendor's Helm chart – with ParcelPal's own values kept in Git.


Duration	~45 min
You create	`work/gitops/argocd/shop-dev.yaml`, `shop-prod.yaml`, `status.yaml`
Solution	`solutions/LAB04/` (or `./bin/lab catchup 4`)

How Argo CD decides what a source is:

Found in the path	Tool
`kustomization.yaml`	Kustomize
`Chart.yaml` (or `chart:` from a Helm repo)	Helm
`*.jsonnet`	Jsonnet
anything else	plain directory of YAML/JSON
configured plugin	Config Management Plugin (sidecar)

The repo server renders everything to plain manifests – the controller only ever sees YAML.

Part A – Kustomize overlays¶

cd work/gitops
find apps/shop -type f              # base/ + overlays/dev, overlays/prod
kubectl kustomize apps/shop/overlays/dev | grep -E 'host:|value:|replicas:'

The overlays change host name, message, colour and replicas. Create one Application per environment:

for env in dev prod; do cat > argocd/shop-$env.yaml <<EOF
apiVersion: argoproj.io/v1alpha1
kind: Application
metadata:
  name: shop-$env
  namespace: argocd
spec:
  project: default
  source:
    repoURL: http://gitea:3000/student/gitops.git
    targetRevision: main
    path: apps/shop/overlays/$env
  destination:
    server: https://kubernetes.default.svc
    namespace: shop-$env
  syncPolicy:
    automated:
      prune: true
      selfHeal: true
    syncOptions:
      - CreateNamespace=true
EOF
done
git add argocd && git commit -m "shop dev + prod" && git push
kubectl apply -f argocd/shop-dev.yaml -f argocd/shop-prod.yaml

✅ Checkpoint: http://shop-dev.localtest.me is orange with shop - dev, http://shop.localtest.me green with shop - prod; kubectl -n shop-prod get pods shows 2 replicas.

Promote a change the GitOps way: give dev a new image in its overlay only:

cat >> apps/shop/overlays/dev/kustomization.yaml <<'EOF'
images:
  - name: ghcr.io/stefanprodan/podinfo
    newTag: 6.16.0
EOF
git commit -am "shop-dev: podinfo 6.16.0" && git push

✅ Checkpoint: shop-dev shows version 6.16.0 (bottom of the page / curl -s shop-dev.localtest.me/version), prod stays on 6.15.0. Promotion to prod = the same change in overlays/prod, via a reviewed pull request.

Argo CD can also override Kustomize settings in the Application (spec.source.kustomize.images, namePrefix, commonLabels…). Prefer Git – overrides in the Application are easy to forget.

Part B – A Helm chart from a Helm repository¶

helm show values podinfo --repo https://stefanprodan.github.io/podinfo --version 6.17.0 | head -40

cat > argocd/status.yaml <<'EOF'
apiVersion: argoproj.io/v1alpha1
kind: Application
metadata:
  name: status
  namespace: argocd
spec:
  project: default
  source:
    repoURL: https://stefanprodan.github.io/podinfo
    chart: podinfo
    targetRevision: 6.17.0
    helm:
      releaseName: status
      valuesObject:
        ui:
          message: "ParcelPal status (inline values)"
        ingress:
          enabled: true
          className: traefik
          hosts:
            - host: status.localtest.me
              paths:
                - path: /
                  pathType: Prefix
  destination:
    server: https://kubernetes.default.svc
    namespace: status
  syncPolicy:
    automated:
      prune: true
      selfHeal: true
    syncOptions:
      - CreateNamespace=true
EOF
kubectl apply -f argocd/status.yaml

✅ Checkpoint: http://status.localtest.me shows inline values. helm list -A shows no release – Argo CD uses helm template and applies the result itself; Helm hooks become Argo CD hooks.

Part C – Multiple sources: chart from the vendor, values from Git¶

Inline values live in the Application – the values file should live next to everything else. helm/status-values.yaml is already in the repo. Change the source block to sources:

  sources:
    - repoURL: https://stefanprodan.github.io/podinfo
      chart: podinfo
      targetRevision: 6.17.0
      helm:
        releaseName: status
        valueFiles:
          - $values/helm/status-values.yaml
    - repoURL: http://gitea:3000/student/gitops.git
      targetRevision: main
      ref: values                          # makes the repo available as $values

git add argocd/status.yaml && git commit -m "status: chart + values from Git" && git push
kubectl apply -f argocd/status.yaml

✅ Checkpoint: the page says all systems operational in steel blue. Edit helm/status-values.yaml (e.g. replicaCount: 2), push – the status app follows.

Imperative overrides exist too: argocd app set status -p replicaCount=3. They are stored in the Application, not in Git – handy for experiments, a trap in production.

Bonus¶

Directory options: create an app for apps/ with directory.recurse: true and directory.include: '{tracker/*.yaml}'. What does Argo CD render?
Helm from OCI: the podinfo chart is also at oci://ghcr.io/stefanprodan/charts/podinfo. Argo CD needs it registered as a Helm repo with Enable OCI.
Compare argocd app manifests status with helm template status podinfo --repo … -f helm/status-values.yaml.

Troubleshooting¶

Symptom	Likely cause
`Unable to resolve '6.17.0' to a Chart version`	chart version typo, or `repoURL` points to the Git repo instead of the Helm repo
`$values/...: no such file`	the second source needs `ref: values`, and the path after `$values/` is relative to that repo's root
shop-dev and shop-prod fight over the same resources	both apps target the same namespace – check `destination.namespace`
`kustomize build` error in the UI	run `kubectl kustomize <path>` locally – same error, faster feedback

Files for this lab: Think-Cube/argocd-labs/labs/LAB04-helm-kustomize