fix(helm): add missing serviceaccount.yaml template

[rupertbenbrook]

Fixes #743

What

Add the missing serviceaccount.yaml template so that serviceAccount.create: true actually creates a ServiceAccount resource.

Why

The chart has serviceAccount.create in values and a plik.serviceAccountName helper in _helpers.tpl, but no template to create the SA. Setting create: true causes the Deployment to reference a non-existent SA, failing pod creation.

Changes

• New: charts/plik/templates/serviceaccount.yaml — standard Helm SA template
• Updated: charts/plik/values.yaml — added serviceAccount.automount field (default: false)
• Updated: charts/plik/CHANGELOG.md — added fix to [Unreleased]
• Updated: charts/plik/ARCHITECTURE.md — added serviceaccount.yaml to structure listing
• Regenerated: charts/plik/README.md via make helm-docs

Testing

Bug reproduction (Kind cluster, chart v1.4.2)

kind create cluster --name plik-test
helm install plik plik/plik --version 1.4.2 \
  --namespace plik-test --create-namespace \
  --set serviceAccount.create=true
kubectl -n plik-test describe replicaset -l app.kubernetes.io/name=plik

Result: Pods fail with error looking up service account plik-test/plik: serviceaccount "plik" not found

Fix verification (Kind cluster, local chart)

helm package charts/plik --destination /tmp/
helm install plik /tmp/plik-*.tgz \
  --namespace plik-test --create-namespace \
  --set serviceAccount.create=true
kubectl -n plik-test wait --for=condition=available deployment/plik --timeout=120s

Result: ✅ Deployment available, pods running, ServiceAccount created

Functional verification (CLI smoke test against Kind deployment)

make client
kubectl -n plik-test port-forward svc/plik 18080:8080 &
echo "test file" > /tmp/plik-test.txt
client/plik --server http://localhost:18080 /tmp/plik-test.txt
curl -s "<download-url>"

Result: ✅ File uploaded and downloaded successfully

Template verification

# With create=true: SA resource rendered
helm template plik charts/plik --set serviceAccount.create=true | grep "kind: ServiceAccount"
# ✅ ServiceAccount rendered

# With create=false (default): uses "default" SA
helm template plik charts/plik | grep serviceAccountName
# ✅ serviceAccountName: default

Project tests

make lint       # ✅ go fmt + go vet + go fix passed
make test       # ✅ all tests passed (server, e2e, handlers, metadata, middleware, crypto)
make helm-docs  # ✅ README.md up to date
make helm       # ✅ chart packages correctly

Environment

• Kubernetes: 1.33.8 (AKS), 1.35.0 (Kind v0.31.0)
• Helm: 4.1.4
• Go: 1.26.2
• Chart: 1.4.2

[rupertbenbrook]

@camathieu @bodji Slightly odd that the frontend tests would fail when I've not changed anything of the frontend. Could it be a transient failure and the tests just need rerunning?

[camathieu]

I'll investigate the flaky test.

[camathieu]

Let's merge, @bodji told me it's all good :)