Tools: HELM — COMPLETE CORE CONCEPTS & CHART EXPLANATION

1. What Helm Is (CORE IDEA) ## 2. Helm Core Concepts (ABSOLUTELY REQUIRED) ## 2.1 Chart (CORE OBJECT) ## 2.2 Values (CONFIGURATION LAYER) ## 2.3 Templates (YAML GENERATORS) ## 2.4 Release (RUNTIME OBJECT) ## 3. Rendering (MOST IMPORTANT HELM MECHANISM) ## 4. Helm Chart Structure — FILE BY FILE (DETAILED) ## 5. Chart.yaml — METADATA (NOT DEPLOYMENT) ## Important distinctions: ## 6. values.yaml — DEFAULT CONFIGURATION ## 7. values-dev.yaml & values-prod.yaml — ENVIRONMENT CONTROL ## Dev example: ## Prod example: ## 8. templates/deployment.yaml — CORE WORKLOAD ## Replica control ## Image control ## ConfigMap injection ## 9. templates/service.yaml — NETWORKING ## Why NodePort failed earlier ## 10. templates/configmap.yaml — CONFIG SEPARATION ## 11. _helpers.tpl — REUSABLE LOGIC (ADVANCED CORE) ## 12. Helm Lifecycle (WHAT DEVOPS USES DAILY) ## Install ## Upgrade ## History ## Rollback ## 13. Helm History & Failures (PRODUCTION CORE) ## 14. Bitnami Charts — WHAT THEY TEACH ## 15. Who Manages Helm in Production ## 16. Troubleshooting Helm (REAL FLOW) ## Helm-side ## Kubernetes-side ## 17. Final Project (STUDENTS MUST DO) ## FINAL CORE MESSAGE ## 🚀 HELM PROJECT ## Production-Ready Helm Deployment Using Existing Chart ## 🎯 Project Goal (What This Proves) ## 🧩 Starting Point (Already Done) ## 📌 PROJECT SCENARIO (REALISTIC) ## 🧪 PROJECT TASKS (STEP-BY-STEP) ## 🔹 TASK 1 — Prove Helm Rendering (Core Understanding) ## Commands ## Deliverable ## 🔹 TASK 2 — Environment Separation (Dev vs Prod) ## Requirements ## Files to edit ## 🔹 TASK 3 — Helm History & Failure Simulation (CRITICAL) ## Step 1 — Break DEV on purpose ## Step 2 — Inspect failure ## Step 3 — Fix & recover ## Deliverable ## 🔹 TASK 4 — Rollback (Production Safety) ## Deliverable ## 🔹 TASK 5 — Production Hardening (Chart Expansion) ## 5.1 Add Resource Limits ## 5.2 Add Readiness & Liveness Probes ## Deliverable ## 🔹 TASK 6 — _helpers.tpl (Professional Helm) ## 🔹 TASK 7 — Bitnami Comparison (Enterprise Learning) ## Deliverable ## 🔹 TASK 8 — Ownership & Workflow (DevOps Reality) ## Explain in words (no code): ## 🔹 TASK 9 — Troubleshooting Checklist ## 🎓 WHAT THIS PROJECT PROVES Production-grade, based on existing chart Helm is not Kubernetes and not a deployment engine. Helm is a package manager and release manager for Kubernetes. Helm does two things only: Everything else is Kubernetes. Helm has four core concepts. A chart is a versioned, reusable application package. In your case, the chart is the entire directory: In real companies: One microservice = one Helm chart Values are input parameters for templates. Your chart already uses multi-environment values: This is exactly how production charts are built. Templates are Kubernetes manifests with variables. Kubernetes cannot read templates. Helm replaces variables → produces valid YAML → sends to Kubernetes. A release is a deployed instance of a chart. Release name + namespace = Helm identity Rendering = converting templates + values into plain Kubernetes YAML What happens internally: Helm never runs containers Helm never manages pods Below is exactly what each file is and why it exists. Helm upgrades track chart version, not appVersion. Same chart, different behavior This is Helm’s biggest value. Key sections to explain to students: Helm does not care what’s inside the container Helm only controls how it’s deployed This is a real production lesson. Helm promotes 12-factor app design _helpers.tpl is mandatory in production charts kubectl apply cannot do this. Helm never deletes failed revisions Bitnami charts include: Bitnami shows how production charts are built ❌ Never kubectl apply Helm-managed resources Helm problems = template/value Pod problems = Kubernetes/runtime This proves Helm mastery. Helm is not about convenience. Helm is about control, safety, audit, and scale. By completing this project, a student demonstrates that they: And running releases: Your company runs a web application called demo-app. The same application must run in DEV and PROD with different behavior. Helm is the only allowed deployment tool. Show that Helm only generates YAML. Demonstrate Helm failure tracking. Make the chart production-ready. 📄 templates/deployment.yaml Add under container spec: 📄 templates/deployment.yaml Standardize labels and naming. 📄 templates/_helpers.tpl Use in all templates: Understand production-grade charts. Platform team owns charts, DevOps manages releases, developers only change images. Student must demonstrate: “ use of Helm in production, manage environments, failures, rollbacks, and chart evolution.” This is real DevOps skill, not theory. Templates let you quickly answer FAQs or store snippets for re-use. Are you sure you want to hide this comment? It will become hidden in your post, but will still be visible via the comment's permalink. Hide child comments as well For further actions, you may consider blocking this person and/or reporting abuse CODE_BLOCK: chart/ Enter fullscreen mode Exit fullscreen mode CODE_BLOCK: values.yaml → defaults values-dev.yaml → dev overrides values-prod.yaml → prod overrides Enter fullscreen mode Exit fullscreen mode CODE_BLOCK: values.yaml → defaults values-dev.yaml → dev overrides values-prod.yaml → prod overrides CODE_BLOCK: values.yaml → defaults values-dev.yaml → dev overrides values-prod.yaml → prod overrides CODE_BLOCK: replicas: {{ .Values.replicaCount }} Enter fullscreen mode Exit fullscreen mode CODE_BLOCK: replicas: {{ .Values.replicaCount }} CODE_BLOCK: replicas: {{ .Values.replicaCount }} CODE_BLOCK: demo-app-dev (namespace: demo) demo-app-prod (namespace: prod) Enter fullscreen mode Exit fullscreen mode CODE_BLOCK: demo-app-dev (namespace: demo) demo-app-prod (namespace: prod) CODE_BLOCK: demo-app-dev (namespace: demo) demo-app-prod (namespace: prod) CODE_BLOCK: helm template demo-app . -f values-dev.yaml Enter fullscreen mode Exit fullscreen mode CODE_BLOCK: helm template demo-app . -f values-dev.yaml CODE_BLOCK: helm template demo-app . -f values-dev.yaml CODE_BLOCK: chart/ ├── Chart.yaml ├── charts/ ├── templates/ │ ├── deployment.yaml │ ├── service.yaml │ ├── configmap.yaml │ └── _helpers.tpl ├── values.yaml ├── values-dev.yaml └── values-prod.yaml Enter fullscreen mode Exit fullscreen mode CODE_BLOCK: chart/ ├── Chart.yaml ├── charts/ ├── templates/ │ ├── deployment.yaml │ ├── service.yaml │ ├── configmap.yaml │ └── _helpers.tpl ├── values.yaml ├── values-dev.yaml └── values-prod.yaml CODE_BLOCK: chart/ ├── Chart.yaml ├── charts/ ├── templates/ │ ├── deployment.yaml │ ├── service.yaml │ ├── configmap.yaml │ └── _helpers.tpl ├── values.yaml ├── values-dev.yaml └── values-prod.yaml CODE_BLOCK: chart/Chart.yaml Enter fullscreen mode Exit fullscreen mode CODE_BLOCK: chart/Chart.yaml CODE_BLOCK: chart/Chart.yaml CODE_BLOCK: apiVersion: v2 name: chart version: 0.1.0 appVersion: "1.16.0" Enter fullscreen mode Exit fullscreen mode CODE_BLOCK: apiVersion: v2 name: chart version: 0.1.0 appVersion: "1.16.0" CODE_BLOCK: apiVersion: v2 name: chart version: 0.1.0 appVersion: "1.16.0" CODE_BLOCK: chart/values.yaml Enter fullscreen mode Exit fullscreen mode CODE_BLOCK: chart/values.yaml CODE_BLOCK: chart/values.yaml CODE_BLOCK: replicaCount: 1 image: repository: nginx tag: "1.25" service: type: ClusterIP port: 80 Enter fullscreen mode Exit fullscreen mode CODE_BLOCK: replicaCount: 1 image: repository: nginx tag: "1.25" service: type: ClusterIP port: 80 CODE_BLOCK: replicaCount: 1 image: repository: nginx tag: "1.25" service: type: ClusterIP port: 80 CODE_BLOCK: chart/values-dev.yaml chart/values-prod.yaml Enter fullscreen mode Exit fullscreen mode CODE_BLOCK: chart/values-dev.yaml chart/values-prod.yaml CODE_BLOCK: chart/values-dev.yaml chart/values-prod.yaml CODE_BLOCK: replicaCount: 1 service: type: NodePort nodePort: 30081 Enter fullscreen mode Exit fullscreen mode CODE_BLOCK: replicaCount: 1 service: type: NodePort nodePort: 30081 CODE_BLOCK: replicaCount: 1 service: type: NodePort nodePort: 30081 CODE_BLOCK: replicaCount: 3 service: type: ClusterIP resources: limits: cpu: "500m" memory: "512Mi" Enter fullscreen mode Exit fullscreen mode CODE_BLOCK: replicaCount: 3 service: type: ClusterIP resources: limits: cpu: "500m" memory: "512Mi" CODE_BLOCK: replicaCount: 3 service: type: ClusterIP resources: limits: cpu: "500m" memory: "512Mi" CODE_BLOCK: chart/templates/deployment.yaml Enter fullscreen mode Exit fullscreen mode CODE_BLOCK: chart/templates/deployment.yaml CODE_BLOCK: chart/templates/deployment.yaml CODE_BLOCK: replicas: {{ .Values.replicaCount }} Enter fullscreen mode Exit fullscreen mode CODE_BLOCK: replicas: {{ .Values.replicaCount }} CODE_BLOCK: replicas: {{ .Values.replicaCount }} CODE_BLOCK: image: "{{ .Values.image.repository }}:{{ .Values.image.tag }}" Enter fullscreen mode Exit fullscreen mode CODE_BLOCK: image: "{{ .Values.image.repository }}:{{ .Values.image.tag }}" CODE_BLOCK: image: "{{ .Values.image.repository }}:{{ .Values.image.tag }}" CODE_BLOCK: envFrom: - configMapRef: name: app-config Enter fullscreen mode Exit fullscreen mode CODE_BLOCK: envFrom: - configMapRef: name: app-config CODE_BLOCK: envFrom: - configMapRef: name: app-config CODE_BLOCK: chart/templates/service.yaml Enter fullscreen mode Exit fullscreen mode CODE_BLOCK: chart/templates/service.yaml CODE_BLOCK: chart/templates/service.yaml CODE_BLOCK: type: {{ .Values.service.type }} ports: - port: {{ .Values.service.port }} nodePort: {{ .Values.service.nodePort }} Enter fullscreen mode Exit fullscreen mode CODE_BLOCK: type: {{ .Values.service.type }} ports: - port: {{ .Values.service.port }} nodePort: {{ .Values.service.nodePort }} CODE_BLOCK: type: {{ .Values.service.type }} ports: - port: {{ .Values.service.port }} nodePort: {{ .Values.service.nodePort }} CODE_BLOCK: chart/templates/configmap.yaml Enter fullscreen mode Exit fullscreen mode CODE_BLOCK: chart/templates/configmap.yaml CODE_BLOCK: chart/templates/configmap.yaml CODE_BLOCK: data: APP_ENV: {{ .Values.env }} Enter fullscreen mode Exit fullscreen mode CODE_BLOCK: data: APP_ENV: {{ .Values.env }} CODE_BLOCK: data: APP_ENV: {{ .Values.env }} CODE_BLOCK: chart/templates/_helpers.tpl Enter fullscreen mode Exit fullscreen mode CODE_BLOCK: chart/templates/_helpers.tpl CODE_BLOCK: chart/templates/_helpers.tpl CODE_BLOCK: {{- define "demo.labels" -}} app.kubernetes.io/name: {{ .Chart.Name }} app.kubernetes.io/instance: {{ .Release.Name }} app.kubernetes.io/managed-by: Helm {{- end }} Enter fullscreen mode Exit fullscreen mode CODE_BLOCK: {{- define "demo.labels" -}} app.kubernetes.io/name: {{ .Chart.Name }} app.kubernetes.io/instance: {{ .Release.Name }} app.kubernetes.io/managed-by: Helm {{- end }} CODE_BLOCK: {{- define "demo.labels" -}} app.kubernetes.io/name: {{ .Chart.Name }} app.kubernetes.io/instance: {{ .Release.Name }} app.kubernetes.io/managed-by: Helm {{- end }} CODE_BLOCK: labels: {{- include "demo.labels" . | nindent 4 }} Enter fullscreen mode Exit fullscreen mode CODE_BLOCK: labels: {{- include "demo.labels" . | nindent 4 }} CODE_BLOCK: labels: {{- include "demo.labels" . | nindent 4 }} CODE_BLOCK: helm install demo-app-dev . -n demo -f values-dev.yaml Enter fullscreen mode Exit fullscreen mode CODE_BLOCK: helm install demo-app-dev . -n demo -f values-dev.yaml CODE_BLOCK: helm install demo-app-dev . -n demo -f values-dev.yaml CODE_BLOCK: helm upgrade demo-app-dev . -n demo -f values-dev.yaml Enter fullscreen mode Exit fullscreen mode CODE_BLOCK: helm upgrade demo-app-dev . -n demo -f values-dev.yaml CODE_BLOCK: helm upgrade demo-app-dev . -n demo -f values-dev.yaml CODE_BLOCK: helm history demo-app-dev -n demo Enter fullscreen mode Exit fullscreen mode CODE_BLOCK: helm history demo-app-dev -n demo CODE_BLOCK: helm history demo-app-dev -n demo CODE_BLOCK: helm rollback demo-app-dev 1 -n demo Enter fullscreen mode Exit fullscreen mode CODE_BLOCK: helm rollback demo-app-dev 1 -n demo CODE_BLOCK: helm rollback demo-app-dev 1 -n demo CODE_BLOCK: helm install redis bitnami/redis Enter fullscreen mode Exit fullscreen mode CODE_BLOCK: helm install redis bitnami/redis CODE_BLOCK: helm install redis bitnami/redis COMMAND_BLOCK: kubectl get sts kubectl get pvc kubectl describe pod redis-master-0 Enter fullscreen mode Exit fullscreen mode COMMAND_BLOCK: kubectl get sts kubectl get pvc kubectl describe pod redis-master-0 COMMAND_BLOCK: kubectl get sts kubectl get pvc kubectl describe pod redis-master-0 CODE_BLOCK: helm lint . helm template . helm get manifest demo-app-dev -n demo helm get values demo-app-dev -n demo Enter fullscreen mode Exit fullscreen mode CODE_BLOCK: helm lint . helm template . helm get manifest demo-app-dev -n demo helm get values demo-app-dev -n demo CODE_BLOCK: helm lint . helm template . helm get manifest demo-app-dev -n demo helm get values demo-app-dev -n demo COMMAND_BLOCK: kubectl describe pod kubectl logs pod kubectl get events Enter fullscreen mode Exit fullscreen mode COMMAND_BLOCK: kubectl describe pod kubectl logs pod kubectl get events COMMAND_BLOCK: kubectl describe pod kubectl logs pod kubectl get events CODE_BLOCK: chart/ ├── Chart.yaml ├── templates/ │ ├── deployment.yaml │ ├── service.yaml │ ├── configmap.yaml │ └── _helpers.tpl ├── values.yaml ├── values-dev.yaml └── values-prod.yaml Enter fullscreen mode Exit fullscreen mode CODE_BLOCK: chart/ ├── Chart.yaml ├── templates/ │ ├── deployment.yaml │ ├── service.yaml │ ├── configmap.yaml │ └── _helpers.tpl ├── values.yaml ├── values-dev.yaml └── values-prod.yaml CODE_BLOCK: chart/ ├── Chart.yaml ├── templates/ │ ├── deployment.yaml │ ├── service.yaml │ ├── configmap.yaml │ └── _helpers.tpl ├── values.yaml ├── values-dev.yaml └── values-prod.yaml CODE_BLOCK: demo-app-dev → namespace demo demo-app-prod → namespace prod Enter fullscreen mode Exit fullscreen mode CODE_BLOCK: demo-app-dev → namespace demo demo-app-prod → namespace prod CODE_BLOCK: demo-app-dev → namespace demo demo-app-prod → namespace prod CODE_BLOCK: helm template demo-app . -f values-dev.yaml helm template demo-app . -f values-prod.yaml Enter fullscreen mode Exit fullscreen mode CODE_BLOCK: helm template demo-app . -f values-dev.yaml helm template demo-app . -f values-prod.yaml CODE_BLOCK: helm template demo-app . -f values-dev.yaml helm template demo-app . -f values-prod.yaml CODE_BLOCK: replicaCount: 1 service: type: NodePort nodePort: 30081 Enter fullscreen mode Exit fullscreen mode CODE_BLOCK: replicaCount: 1 service: type: NodePort nodePort: 30081 CODE_BLOCK: replicaCount: 1 service: type: NodePort nodePort: 30081 CODE_BLOCK: replicaCount: 3 service: type: ClusterIP Enter fullscreen mode Exit fullscreen mode CODE_BLOCK: replicaCount: 3 service: type: ClusterIP CODE_BLOCK: replicaCount: 3 service: type: ClusterIP CODE_BLOCK: helm upgrade demo-app-dev . -n demo -f values-dev.yaml helm upgrade demo-app-prod . -n prod -f values-prod.yaml Enter fullscreen mode Exit fullscreen mode CODE_BLOCK: helm upgrade demo-app-dev . -n demo -f values-dev.yaml helm upgrade demo-app-prod . -n prod -f values-prod.yaml CODE_BLOCK: helm upgrade demo-app-dev . -n demo -f values-dev.yaml helm upgrade demo-app-prod . -n prod -f values-prod.yaml COMMAND_BLOCK: service: type: NodePort nodePort: 28000 # INVALID Enter fullscreen mode Exit fullscreen mode COMMAND_BLOCK: service: type: NodePort nodePort: 28000 # INVALID COMMAND_BLOCK: service: type: NodePort nodePort: 28000 # INVALID CODE_BLOCK: helm upgrade demo-app-dev . -n demo -f values-dev.yaml Enter fullscreen mode Exit fullscreen mode CODE_BLOCK: helm upgrade demo-app-dev . -n demo -f values-dev.yaml CODE_BLOCK: helm upgrade demo-app-dev . -n demo -f values-dev.yaml CODE_BLOCK: helm history demo-app-dev -n demo helm get manifest demo-app-dev -n demo --revision 1 Enter fullscreen mode Exit fullscreen mode CODE_BLOCK: helm history demo-app-dev -n demo helm get manifest demo-app-dev -n demo --revision 1 CODE_BLOCK: helm history demo-app-dev -n demo helm get manifest demo-app-dev -n demo --revision 1 CODE_BLOCK: nodePort: 30082 Enter fullscreen mode Exit fullscreen mode CODE_BLOCK: nodePort: 30082 CODE_BLOCK: nodePort: 30082 CODE_BLOCK: helm upgrade demo-app-dev . -n demo -f values-dev.yaml Enter fullscreen mode Exit fullscreen mode CODE_BLOCK: helm upgrade demo-app-dev . -n demo -f values-dev.yaml CODE_BLOCK: helm upgrade demo-app-dev . -n demo -f values-dev.yaml CODE_BLOCK: helm history demo-app-dev -n demo helm rollback demo-app-dev 1 -n demo Enter fullscreen mode Exit fullscreen mode CODE_BLOCK: helm history demo-app-dev -n demo helm rollback demo-app-dev 1 -n demo CODE_BLOCK: helm history demo-app-dev -n demo helm rollback demo-app-dev 1 -n demo COMMAND_BLOCK: kubectl get pods -n demo Enter fullscreen mode Exit fullscreen mode COMMAND_BLOCK: kubectl get pods -n demo COMMAND_BLOCK: kubectl get pods -n demo CODE_BLOCK: resources: requests: cpu: {{ .Values.resources.requests.cpu }} memory: {{ .Values.resources.requests.memory }} limits: cpu: {{ .Values.resources.limits.cpu }} memory: {{ .Values.resources.limits.memory }} Enter fullscreen mode Exit fullscreen mode CODE_BLOCK: resources: requests: cpu: {{ .Values.resources.requests.cpu }} memory: {{ .Values.resources.requests.memory }} limits: cpu: {{ .Values.resources.limits.cpu }} memory: {{ .Values.resources.limits.memory }} CODE_BLOCK: resources: requests: cpu: {{ .Values.resources.requests.cpu }} memory: {{ .Values.resources.requests.memory }} limits: cpu: {{ .Values.resources.limits.cpu }} memory: {{ .Values.resources.limits.memory }} CODE_BLOCK: resources: requests: cpu: "200m" memory: "256Mi" limits: cpu: "500m" memory: "512Mi" Enter fullscreen mode Exit fullscreen mode CODE_BLOCK: resources: requests: cpu: "200m" memory: "256Mi" limits: cpu: "500m" memory: "512Mi" CODE_BLOCK: resources: requests: cpu: "200m" memory: "256Mi" limits: cpu: "500m" memory: "512Mi" CODE_BLOCK: readinessProbe: httpGet: path: / port: 80 initialDelaySeconds: 5 livenessProbe: httpGet: path: / port: 80 initialDelaySeconds: 15 Enter fullscreen mode Exit fullscreen mode CODE_BLOCK: readinessProbe: httpGet: path: / port: 80 initialDelaySeconds: 5 livenessProbe: httpGet: path: / port: 80 initialDelaySeconds: 15 CODE_BLOCK: readinessProbe: httpGet: path: / port: 80 initialDelaySeconds: 5 livenessProbe: httpGet: path: / port: 80 initialDelaySeconds: 15 CODE_BLOCK: {{- define "demo.labels" -}} app.kubernetes.io/name: {{ .Chart.Name }} app.kubernetes.io/instance: {{ .Release.Name }} app.kubernetes.io/version: {{ .Chart.AppVersion }} app.kubernetes.io/managed-by: Helm {{- end }} Enter fullscreen mode Exit fullscreen mode CODE_BLOCK: {{- define "demo.labels" -}} app.kubernetes.io/name: {{ .Chart.Name }} app.kubernetes.io/instance: {{ .Release.Name }} app.kubernetes.io/version: {{ .Chart.AppVersion }} app.kubernetes.io/managed-by: Helm {{- end }} CODE_BLOCK: {{- define "demo.labels" -}} app.kubernetes.io/name: {{ .Chart.Name }} app.kubernetes.io/instance: {{ .Release.Name }} app.kubernetes.io/version: {{ .Chart.AppVersion }} app.kubernetes.io/managed-by: Helm {{- end }} CODE_BLOCK: labels: {{- include "demo.labels" . | nindent 4 }} Enter fullscreen mode Exit fullscreen mode CODE_BLOCK: labels: {{- include "demo.labels" . | nindent 4 }} CODE_BLOCK: labels: {{- include "demo.labels" . | nindent 4 }} CODE_BLOCK: helm install redis bitnami/redis helm install nginx bitnami/nginx Enter fullscreen mode Exit fullscreen mode CODE_BLOCK: helm install redis bitnami/redis helm install nginx bitnami/nginx CODE_BLOCK: helm install redis bitnami/redis helm install nginx bitnami/nginx COMMAND_BLOCK: kubectl get sts kubectl get pvc kubectl describe pod redis-master-0 Enter fullscreen mode Exit fullscreen mode COMMAND_BLOCK: kubectl get sts kubectl get pvc kubectl describe pod redis-master-0 COMMAND_BLOCK: kubectl get sts kubectl get pvc kubectl describe pod redis-master-0 CODE_BLOCK: helm lint . helm template . helm status demo-app-dev -n demo helm get values demo-app-dev -n demo kubectl describe pod kubectl logs pod Enter fullscreen mode Exit fullscreen mode CODE_BLOCK: helm lint . helm template . helm status demo-app-dev -n demo helm get values demo-app-dev -n demo kubectl describe pod kubectl logs pod CODE_BLOCK: helm lint . helm template . helm status demo-app-dev -n demo helm get values demo-app-dev -n demo kubectl describe pod kubectl logs pod - Renders Kubernetes YAML from templates and values - Tracks deployment history (revisions) - lives for years - is not recreated per deployment - represents one application - environment behavior - Helm reads Chart.yaml - Helm loads values - Helm processes templates - Helm outputs pure YAML - Kubernetes API receives YAML - chart identity - dependency declaration - version → chart version (Helm logic) - appVersion → application version (informational) - base configuration - safe defaults - common settings - should work everywhere - should not be environment-specific - override defaults - avoid YAML duplication - separate environments - defines Pod lifecycle - describes containers - uses values for customization - expose pods - define access model - Kubernetes validates NodePort range - Helm only renders YAML - Invalid value caused revision 1 failure - externalize configuration - avoid image rebuilds - environment-specific config - avoid duplication - standardize naming - enforce labels - revision 1 → failed (NodePort) - revision 2 → deployed - traceability - rollback safety - StatefulSets - SecurityContext - Take existing chart - resource limits - _helpers.tpl labels Deploy: - dev (NodePort) - prod (ClusterIP) Trigger failure Fix via helm upgrade Rollback - Trigger failure - Fix via helm upgrade - Trigger failure - Fix via helm upgrade - Understand Helm core concepts - Can manage multiple environments (dev/prod) - Can troubleshoot real Helm failures - Can safely upgrade & rollback - Can extend a chart to production quality - Understand who manages Helm in real companies - Why outputs are different - Why Kubernetes never sees templates - Why Helm kept the failed revision - Why Kubernetes rejected it - Why Helm did not delete history - What rollback actually does - Why this is safer than kubectl - Why probes are Kubernetes responsibility - Why Helm only injects configuration - Why Bitnami uses StatefulSets - Why PVCs are mandatory - What you’d copy into your own charts - Who owns charts? - Who changes values? - Who triggers upgrades? - Why kubectl apply is forbidden? - Helm error vs Kubernetes error - Where to look first