Helm-chart-k8s

Helm chart for k8s deployments.

This Helm chart deploys a containerized backend application on Kubernetes with flexible configuration for networking, scaling, scheduling, and environment-specific deployment strategies. It is designed to work well on Amazon EKS, supporting AWS ALB Ingress, NGINX Ingress, autoscaling, and common production requirements.

---

Overview

This chart provides:

• Deployment of a backend container from AWS ECR
• Configurable Service (ClusterIP / Headless)
• AWS ALB Ingress or NGINX Ingress support
• Horizontal Pod Autoscaler (HPA)
• Vertical Pod Autoscaler (VPA)
• ConfigMaps for files and environment variables
• Node affinity, tolerations, and node selectors
• Liveness & readiness probes
• RollingUpdate or Recreate deployment strategies
• Git metadata injection for traceability

---

Prerequisites

• Kubernetes v1.32+
• Helm v3.x
• (For ALB) AWS Load Balancer Controller installed
• (For NGINX) NGINX Ingress Controller installed
• Access to AWS ECR (if using private images)

---

Chart Structure

helm-base-chart/
├── Chart.yaml
├── values.yaml
├── templates/
│   ├── deployment.yaml
│   ├── service.yaml
│   ├── ingress.yaml
│   ├── hpa.yaml
│   ├── vpa.yaml
│   └── configmap.yaml
└── README.md

---

Lifecyle-Helm chart

Install the chart

helm install backend-app ./helm-base-chart \
  --namespace dev \
  --create-namespace

Upgrade

helm upgrade backend-app ./helm-base-chart -n dev

Uninstall

helm uninstall backend-app -n dev

Config control

All configuration is controlled via `values.yaml`. If needed, can pass custom values as `stage.values.yaml` as `args`.

---

Image Configuration

image:
  repository: <aws-ecr-repo>
  tag: be_v-5
  pullPolicy: IfNotPresent

---

Service Configuration

service:
  enabled: true
  type: ClusterIP
  headless: false
  port: 80
  targetPort: 6000

Field	Description
enabled	Enable or disable Service creation
type	Kubernetes Service type
headless	Enable headless service

---

Resource Management

resources:
  limits:
    memory: 128Mi
    cpu: 500m
  requests:
    memory: 64Mi
    cpu: 250m

Defines CPU and memory requests and limits for the container.

---

Image Pull Secrets

imagePullSecrets:
  enabled: false
  values:
    - name: credreg-1

Enable this when pulling images from private registries.

---

Special Features

Git Metadata

gitBranch: master
gitCommit: "HEAD"
gitBuildNumber: "10"
gitBuildTimestamp: "20241010"

These values can be injected as labels or environment variables for:

• Debugging
• Deployment traceability
• Observability

Affinity Rules

affinity:
  enabled: false

Supports:

• Required and preferred node affinity
• Spot / on-demand node scheduling

Custom Container Command

command:
  enabled: false

Override the container entrypoint when required.

Multi-Ingress Configuration (AWS ALB & Nginx)

AWS ALB Ingress

ingress:
  enabled: true
  className: alb

Field	Description
annotations	ALB-specific annotations
rules	Host and path rules
tls	TLS configuration

NGINX Ingress (Alternative)

nginx:
  enabled: false

Use this when deploying with the NGINX ingress controller instead of ALB.

Autoscaling (HPA)

autoscaling:
  enabled: false

Supports:

• CPU-based scaling
• Memory-based scaling

Field	Description
minReplicas	Minimum replicas
maxReplicas	Maximum replicas

Vertical Pod Autoscaler (VPA)

vpa:
  enabled: false
  updateMode: "Off"

Controls automatic resource tuning.

ConfigMap Support i.e, configmaps can be mounted as volume

configmap:
  enabled: false

Supports:

• File-based configuration
• Environment variables

Useful for application configuration without rebuilding images.

Node Selector

nodeSelector:
  enabled: false

Restrict pods to specific nodes.

Tolerations

tolerations:
  enabled: false

Allow scheduling onto tainted nodes.

Liveness Probe

livenessProbe:
  enabled: false

Readiness Probe

readinessProbe:
  enabled: false

Improves application reliability and rollout safety.

Deployment Strategy- For Lower & Higher Env Strategy

lowerenvStrategy:
  enabled: true

Uses 'Recreate' strategy for dev/test environments.

Default Strategy

strategy:
  type: RollingUpdate
  maxUnavailable: 50%
  maxSurge: 1

Recommended for staging and production.

Example Override

helm install backend-app ./helm-base-chart \
  --set image.tag=be_v-6 \
  --set autoscaling.enabled=true
  --values stage.values.yaml

Best Practices

• Use RollingUpdate for production
• Enable probes for zero-downtime deployments
• Use Spot enablement for cost cutting
• Use HPA for variable traffic
• Use ConfigMaps for non-secret configs
• Track builds using Git metadata