# Helm Chart Design

> **For Claude:** REQUIRED SUB-SKILL: Use superpowers:executing-plans to implement this plan task-by-task.

**Goal:** Add Helm chart for Kubernetes deployment as an alternative to Docker Compose.

**Architecture:** Single Helm chart deploying frontend (nginx) and backend (Node.js) services with PVC for SQLite persistence and Ingress for external access.

**Tech Stack:** Helm 3, Kubernetes

---

## Chart Structure

```
helm/cv-app/
├── Chart.yaml
├── values.yaml
├── templates/
│   ├── _helpers.tpl
│   ├── frontend-deployment.yaml
│   ├── frontend-service.yaml
│   ├── backend-deployment.yaml
│   ├── backend-service.yaml
│   ├── ingress.yaml
│   ├── configmap.yaml
│   ├── secret.yaml
│   ├── pvc.yaml
│   └── NOTES.txt
└── .helmignore
```

## Components

### Frontend

- **Deployment**: nginx serving built React static files
- **Service**: ClusterIP on port 80
- **Environment**: API URL from ConfigMap

### Backend

- **Deployment**: Node.js Express server
- **Service**: ClusterIP on port 3001
- **Volume**: PVC mount at `/app/data` for SQLite
- **Environment**: Port, DB path, auth config from ConfigMap/Secret

### Ingress

- Routes `/` → frontend service
- Routes `/api` → backend service
- Configurable TLS
- Supports nginx, traefik ingress controllers

### Persistence

- PVC for SQLite database
- Configurable storage class
- 1Gi default size

## Values Schema

```yaml
frontend:
  replicaCount: 1
  image:
    repository: username/cv-app
    tag: latest
    pullPolicy: IfNotPresent
  resources: {}

backend:
  replicaCount: 1
  image:
    repository: username/cv-app-backend
    tag: latest
    pullPolicy: IfNotPresent
  auth:
    mode: simple
  keycloak:
    url: ""
    realm: ""
    clientId: ""
  resources: {}

persistence:
  enabled: true
  size: 1Gi
  storageClass: ""

ingress:
  enabled: true
  className: ""
  annotations: {}
  hosts:
    - host: cv.local
      paths:
        - path: /
          service: frontend
        - path: /api
          service: backend
  tls: []

imagePullSecrets: []
nameOverride: ""
fullnameOverride: ""

serviceAccount:
  create: true
  annotations: {}
  name: ""

podAnnotations: {}
podSecurityContext: {}
securityContext: {}

nodeSelector: {}
tolerations: []
affinity: {}
```

## Templates

### _helpers.tpl

```yaml
{{- define "cv-app.name" -}}
{{- default .Chart.Name .Values.nameOverride | trunc 63 | trimSuffix "-" }}
{{- end }}

{{- define "cv-app.fullname" -}}
{{- if .Values.fullnameOverride }}
{{- .Values.fullnameOverride | trunc 63 | trimSuffix "-" }}
{{- else }}
{{- $name := default .Chart.Name .Values.nameOverride }}
{{- if contains $name .Release.Name }}
{{- .Release.Name | trunc 63 | trimSuffix "-" }}
{{- else }}
{{- printf "%s-%s" .Release.Name $name | trunc 63 | trimSuffix "-" }}
{{- end }}
{{- end }}
{{- end }}

{{- define "cv-app.chart" -}}
{{- printf "%s-%s" .Chart.Name .Chart.Version | replace "+" "_" | trunc 63 | trimSuffix "-" }}
{{- end }}

{{- define "cv-app.labels" -}}
helm.sh/chart: {{ include "cv-app.chart" . }}
{{ include "cv-app.selectorLabels" . }}
{{- if .Chart.AppVersion }}
app.kubernetes.io/version: {{ .Chart.AppVersion | quote }}
{{- end }}
app.kubernetes.io/managed-by: {{ .Release.Service }}
{{- end }}

{{- define "cv-app.selectorLabels" -}}
app.kubernetes.io/name: {{ include "cv-app.name" . }}
app.kubernetes.io/instance: {{ .Release.Name }}
{{- end }}

{{- define "cv-app.serviceAccountName" -}}
{{- if .Values.serviceAccount.create }}
{{- default (include "cv-app.fullname" .) .Values.serviceAccount.name }}
{{- else }}
{{- default "default" .Values.serviceAccount.name }}
{{- end }}
{{- end }}
```

### frontend-deployment.yaml

```yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: {{ include "cv-app.fullname" . }}-frontend
  labels:
    {{- include "cv-app.labels" . | nindent 4 }}
    app.kubernetes.io/component: frontend
spec:
  replicas: {{ .Values.frontend.replicaCount }}
  selector:
    matchLabels:
      {{- include "cv-app.selectorLabels" . | nindent 6 }}
      app.kubernetes.io/component: frontend
  template:
    metadata:
      annotations:
        checksum/config: {{ include (print $.Template.BasePath "/configmap.yaml") . | sha256sum }}
      labels:
        {{- include "cv-app.selectorLabels" . | nindent 8 }}
        app.kubernetes.io/component: frontend
    spec:
      containers:
        - name: frontend
          image: "{{ .Values.frontend.image.repository }}:{{ .Values.frontend.image.tag | default .Chart.AppVersion }}"
          imagePullPolicy: {{ .Values.frontend.image.pullPolicy }}
          ports:
            - name: http
              containerPort: 80
              protocol: TCP
          envFrom:
            - configMapRef:
                name: {{ include "cv-app.fullname" . }}-config
          livenessProbe:
            httpGet:
              path: /
              port: http
          readinessProbe:
            httpGet:
              path: /
              port: http
          resources:
            {{- toYaml .Values.frontend.resources | nindent 12 }}
```

### frontend-service.yaml

```yaml
apiVersion: v1
kind: Service
metadata:
  name: {{ include "cv-app.fullname" . }}-frontend
  labels:
    {{- include "cv-app.labels" . | nindent 4 }}
    app.kubernetes.io/component: frontend
spec:
  type: ClusterIP
  ports:
    - port: 80
      targetPort: http
      protocol: TCP
      name: http
  selector:
    {{- include "cv-app.selectorLabels" . | nindent 4 }}
    app.kubernetes.io/component: frontend
```

### backend-deployment.yaml

```yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: {{ include "cv-app.fullname" . }}-backend
  labels:
    {{- include "cv-app.labels" . | nindent 4 }}
    app.kubernetes.io/component: backend
spec:
  replicas: {{ .Values.backend.replicaCount }}
  selector:
    matchLabels:
      {{- include "cv-app.selectorLabels" . | nindent 6 }}
      app.kubernetes.io/component: backend
  template:
    metadata:
      annotations:
        checksum/config: {{ include (print $.Template.BasePath "/configmap.yaml") . | sha256sum }}
        checksum/secret: {{ include (print $.Template.BasePath "/secret.yaml") . | sha256sum }}
      labels:
        {{- include "cv-app.selectorLabels" . | nindent 8 }}
        app.kubernetes.io/component: backend
    spec:
      containers:
        - name: backend
          image: "{{ .Values.backend.image.repository }}:{{ .Values.backend.image.tag | default .Chart.AppVersion }}"
          imagePullPolicy: {{ .Values.backend.image.pullPolicy }}
          ports:
            - name: http
              containerPort: 3001
              protocol: TCP
          envFrom:
            - configMapRef:
                name: {{ include "cv-app.fullname" . }}-config
            - secretRef:
                name: {{ include "cv-app.fullname" . }}-secret
          volumeMounts:
            - name: data
              mountPath: /app/data
          livenessProbe:
            httpGet:
              path: /health
              port: http
          readinessProbe:
            httpGet:
              path: /health
              port: http
          resources:
            {{- toYaml .Values.backend.resources | nindent 12 }}
      volumes:
        - name: data
          {{- if .Values.persistence.enabled }}
          persistentVolumeClaim:
            claimName: {{ include "cv-app.fullname" . }}-data
          {{- else }}
          emptyDir: {}
          {{- end }}
```

### backend-service.yaml

```yaml
apiVersion: v1
kind: Service
metadata:
  name: {{ include "cv-app.fullname" . }}-backend
  labels:
    {{- include "cv-app.labels" . | nindent 4 }}
    app.kubernetes.io/component: backend
spec:
  type: ClusterIP
  ports:
    - port: 3001
      targetPort: http
      protocol: TCP
      name: http
  selector:
    {{- include "cv-app.selectorLabels" . | nindent 4 }}
    app.kubernetes.io/component: backend
```

### ingress.yaml

```yaml
{{- if .Values.ingress.enabled -}}
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: {{ include "cv-app.fullname" . }}
  labels:
    {{- include "cv-app.labels" . | nindent 4 }}
  {{- with .Values.ingress.annotations }}
  annotations:
    {{- toYaml . | nindent 4 }}
  {{- end }}
spec:
  {{- if .Values.ingress.className }}
  ingressClassName: {{ .Values.ingress.className }}
  {{- end }}
  {{- if .Values.ingress.tls }}
  tls:
    {{- range .Values.ingress.tls }}
    - hosts:
        {{- range .hosts }}
        - {{ . | quote }}
        {{- end }}
      secretName: {{ .secretName }}
    {{- end }}
  {{- end }}
  rules:
    {{- range .Values.ingress.hosts }}
    - host: {{ .host | quote }}
      http:
        paths:
          {{- range .paths }}
          - path: {{ .path }}
            pathType: Prefix
            backend:
              service:
                name: {{ include "cv-app.fullname" $ }}-{{ .service }}
                port:
                  number: {{ if eq .service "frontend" }}80{{ else }}3001{{ end }}
          {{- end }}
    {{- end }}
{{- end }}
```

### configmap.yaml

```yaml
apiVersion: v1
kind: ConfigMap
metadata:
  name: {{ include "cv-app.fullname" . }}-config
  labels:
    {{- include "cv-app.labels" . | nindent 4 }}
data:
  PORT: "3001"
  DB_PATH: "/app/data/cv.db"
  AUTH_MODE: {{ .Values.backend.auth.mode | quote }}
  {{- if eq .Values.backend.auth.mode "keycloak" }}
  KEYCLOAK_URL: {{ .Values.backend.keycloak.url | quote }}
  KEYCLOAK_REALM: {{ .Values.backend.keycloak.realm | quote }}
  KEYCLOAK_CLIENT_ID: {{ .Values.backend.keycloak.clientId | quote }}
  {{- end }}
```

### secret.yaml

```yaml
apiVersion: v1
kind: Secret
metadata:
  name: {{ include "cv-app.fullname" . }}-secret
  labels:
    {{- include "cv-app.labels" . | nindent 4 }}
type: Opaque
data:
  {{- if eq .Values.backend.auth.mode "simple" }}
  JWT_SECRET: {{ randAlphaNum 32 | b64enc | quote }}
  {{- end }}
```

### pvc.yaml

```yaml
{{- if .Values.persistence.enabled -}}
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: {{ include "cv-app.fullname" . }}-data
  labels:
    {{- include "cv-app.labels" . | nindent 4 }}
spec:
  accessModes:
    - ReadWriteOnce
  {{- if .Values.persistence.storageClass }}
  storageClassName: {{ .Values.persistence.storageClass | quote }}
  {{- end }}
  resources:
    requests:
      storage: {{ .Values.persistence.size }}
{{- end }}
```

### NOTES.txt

```
Your CV application has been deployed!

Access your application at:
{{- if .Values.ingress.enabled }}
{{- range $host := .Values.ingress.hosts }}
  http{{ if $.Values.ingress.tls }}s{{ end }}://{{ $host.host }}
{{- end }}
{{- else }}
  Frontend: http://{{ include "cv-app.fullname" . }}-frontend.{{ .Release.Namespace }}.svc.cluster.local
  Backend API: http://{{ include "cv-app.fullname" . }}-backend.{{ .Release.Namespace }}.svc.cluster.local:3001
{{- end }}

{{- if eq .Values.backend.auth.mode "simple" }}
Get the admin password:
  kubectl logs deployment/{{ include "cv-app.fullname" . }}-backend | grep "ADMIN PASSWORD"
{{- end }}

API Documentation:
  http{{ if .Values.ingress.tls }}s{{ end }}://{{ (index .Values.ingress.hosts 0).host }}/api/docs
```

## Usage Examples

### Basic Installation

```bash
helm install cv-app ./helm/cv-app
```

### With Custom Host

```bash
helm install cv-app ./helm/cv-app \
  --set ingress.hosts[0].host=cv.example.com
```

### With TLS

```bash
helm install cv-app ./helm/cv-app \
  --set ingress.hosts[0].host=cv.example.com \
  --set ingress.tls[0].hosts[0]=cv.example.com \
  --set ingress.tls[0].secretName=cv-app-tls
```

### With Keycloak

```bash
helm install cv-app ./helm/cv-app \
  --set backend.auth.mode=keycloak \
  --set backend.keycloak.url=https://keycloak.example.com \
  --set backend.keycloak.realm=myrealm \
  --set backend.keycloak.clientId=cv-app
```

### With Specific Storage Class

```bash
helm install cv-app ./helm/cv-app \
  --set persistence.storageClass=local-path \
  --set persistence.size=5Gi
```