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On-Premise Kubernetes Deployment Guide

React + Node.js + MySQL — Production Deployment

Table of Contents

  1. Prerequisites
  2. Project Structure
  3. Pre-Deployment Checklist
  4. Step-by-Step Deployment
  5. Verify the Deployment
  6. Troubleshooting Guide
  7. Updating the Application
  8. Teardown
  9. CI/CD — Jenkins Multibranch Pipeline
  10. GitOps — ArgoCD (Reference)

1. Prerequisites

Required Tools (on your workstation)

Tool Minimum Version Check Command
kubectl v1.24+ kubectl version --client
kustomize v5.0+ (or use kubectl built-in) kubectl kustomize --help
docker v20+ docker --version
helm v3.0+ helm version

Required on the Kubernetes Cluster

Component Purpose Install Command
NGINX Ingress Controller Routes external traffic See step 4.1
local-path Provisioner Provides PersistentVolumes See step 4.2
myapp.local DNS or hosts entry Browser access See step 4.6

Cluster Requirements

  • Kubernetes v1.24+
  • At least 1 worker node with:
    • 1 CPU core free
    • 2 GB RAM free
    • 5 GB disk free (2 GB for MySQL PVC + OS overhead)
  • kubectl configured with cluster access (kubectl get nodes returns Ready)

2. Project Structure

k8s/
├── base/                          # Shared manifests (all environments)
│   ├── kustomization.yaml         # Generates ConfigMap + Secret from property files
│   ├── config.properties          # Non-sensitive env vars (DB_HOST, DB_PORT, etc.)
│   ├── secret.properties          # Sensitive env vars (passwords) — gitignored
│   ├── namespace.yaml             # Namespace: react-mysql
│   ├── mysql/
│   │   ├── configmap-sql.yaml     # Init SQL mounted at /docker-entrypoint-initdb.d/
│   │   ├── statefulset.yaml       # MySQL 8.0 StatefulSet with PVC + probes
│   │   └── service.yaml           # Headless ClusterIP service for StatefulSet DNS
│   ├── backend/
│   │   ├── deployment.yaml        # Node.js API with init container (waits for MySQL)
│   │   └── service.yaml           # ClusterIP :3000
│   └── frontend/
│       ├── deployment.yaml        # React static site served by `serve`
│       └── service.yaml           # ClusterIP :3000
└── overlays/
    └── onpremise/
        ├── kustomization.yaml     # Extends base, adds ingress
        ├── ingress.yaml           # Two Ingress objects (API rewrite + frontend)
        └── patch-storageclass.yaml # Patches MySQL PVC → storageClassName: local-path

How Traffic Flows

Browser
  │
  ▼
[myapp.local:80]
  │
  ▼
NGINX Ingress Controller
  ├── /api/* ──rewrite /api→/──► backend Service :3000 ──► Node.js Pod
  │                                                            │
  │                                                            ▼
  │                                                        MySQL Service
  │                                                            │
  │                                                            ▼
  │                                                        mysql-0 Pod
  │                                                            │
  │                                                            ▼
  │                                                        PVC (local-path 2Gi)
  │
  └── /    ──────────────────────► frontend Service :3000 ──► React Pod

3. Pre-Deployment Checklist

Run through this before deploying:

# 1. Confirm cluster is reachable
kubectl get nodes

# 2. Confirm you have cluster-admin rights
kubectl auth can-i create namespace --all-namespaces

# 3. Confirm Docker Hub images exist
docker manifest inspect subkamble/react-mysql-backend:latest
docker manifest inspect subkamble/react-mysql-frontend:latest

# 4. Confirm secret.properties exists (it's gitignored, must be created manually)
cat k8s/base/secret.properties

Expected output for step 4:

DB_PASSWORD=pass123
MYSQL_ROOT_PASSWORD=pass123
MYSQL_PASSWORD=pass123

If secret.properties is missing, create it:

cat > k8s/base/secret.properties <<EOF
DB_PASSWORD=pass123
MYSQL_ROOT_PASSWORD=pass123
MYSQL_PASSWORD=pass123
EOF

Replace pass123 with a strong password in production.

4. Step-by-Step Deployment

Step 4.1 — Install NGINX Ingress Controller

helm repo add ingress-nginx https://kubernetes.github.io/ingress-nginx
helm repo update

helm install ingress-nginx ingress-nginx/ingress-nginx \
  --namespace ingress-nginx \
  --create-namespace \
  --set controller.replicaCount=1

# Wait for it to be ready (takes 1-2 min)
kubectl wait deployment/ingress-nginx-controller \
  -n ingress-nginx \
  --for=condition=Available \
  --timeout=120s

# Verify
kubectl get pods -n ingress-nginx

Expected output:

NAME                                        READY   STATUS    RESTARTS
ingress-nginx-controller-xxxxxxxxx-xxxxx    1/1     Running   0

Step 4.2 — Install local-path Storage Provisioner

kubectl apply -f https://raw.githubusercontent.com/rancher/local-path-provisioner/master/deploy/local-path-storage.yaml

# Wait for it to be ready
kubectl wait deployment/local-path-provisioner \
  -n local-path-storage \
  --for=condition=Available \
  --timeout=60s

# Verify the StorageClass exists
kubectl get storageclass

Expected output includes:

NAME         PROVISIONER                RECLAIMPOLICY   VOLUMEBINDINGMODE
local-path   rancher.io/local-path      Delete          WaitForFirstConsumer

Step 4.3 — Verify Kustomize Output (Dry Run)

Always preview what will be applied before deploying:

kubectl kustomize k8s/overlays/onpremise

Verify the output includes:

  • storageClassName: local-path in the StatefulSet volumeClaimTemplate
  • Both Ingress objects (react-mysql-api-ingress and react-mysql-frontend-ingress)
  • ConfigMap app-config-<hash> and Secret app-secret-<hash>

Step 4.4 — Deploy

kubectl apply -k k8s/overlays/onpremise

Expected output:

namespace/react-mysql created
configmap/app-config-7fm29c526g created
configmap/mysql-init-sql created
secret/app-secret-7ht4dgtbc6 created
service/backend created
service/frontend created
service/mysql created
deployment.apps/backend created
deployment.apps/frontend created
statefulset.apps/mysql created
ingress.networking.k8s.io/react-mysql-api-ingress created
ingress.networking.k8s.io/react-mysql-frontend-ingress created

Step 4.5 — Watch Pods Come Up

kubectl get pods -n react-mysql -w

Expected sequence:

Pod First status Final status Time
mysql-0 ContainerCreating 1/1 Running ~30s
backend-xxx Init:0/1 (waiting for MySQL) 1/1 Running ~60s
frontend-xxx Running 1/1 Running ~20s

Note: backend staying in Init:0/1 is normal — the init container runs nc -z mysql 3306 in a loop until MySQL's readiness probe passes. This prevents backend crash-loops due to MySQL not being ready.

Step 4.6 — Configure DNS / hosts

Get the external IP of the Ingress controller:

kubectl get svc -n ingress-nginx ingress-nginx-controller

Look for the EXTERNAL-IP column. Then:

Option A — /etc/hosts (single machine, testing):

echo "<EXTERNAL-IP> myapp.local" | sudo tee -a /etc/hosts

Option B — Internal DNS (production): Create an A record in your internal DNS server:

myapp.local → <EXTERNAL-IP>

Step 4.7 — Verify Ingress Has an Address

kubectl get ingress -n react-mysql

Expected output:

NAME                           CLASS   HOSTS         ADDRESS        PORTS
react-mysql-api-ingress        nginx   myapp.local   <EXTERNAL-IP>  80
react-mysql-frontend-ingress   nginx   myapp.local   <EXTERNAL-IP>  80

If ADDRESS is empty after 2 minutes, see Ingress has no ADDRESS.

5. Verify the Deployment

Run these checks in order:

# 1. All pods Running
kubectl get pods -n react-mysql

# 2. Database table exists
kubectl exec mysql-0 -n react-mysql -- \
  mysql -u root -ppass123 -e "SHOW TABLES FROM appdb;"

# 3. Backend API responds
kubectl port-forward svc/backend 3000:3000 -n react-mysql &
curl localhost:3000/user
# Expected: []
kill %1

# 4. Ingress routes API correctly
curl http://myapp.local/api/user
# Expected: []

# 5. Post a user
curl -X POST http://myapp.local/api/user \
  -H "Content-Type: application/json" \
  -d '{"data":"Alice"}'
# Expected: {"affectedRows":1,...}

# 6. User persists
curl http://myapp.local/api/user
# Expected: [{"id":1,"name":"Alice"}]

# 7. Frontend loads (check Content-Type is text/html)
curl -si http://myapp.local/ | head -5

# 8. Static JS asset loads (must be application/javascript, NOT text/html)
curl -si http://myapp.local/static/js/main.ff70bc14.js | head -3

# 9. PVC persistence — delete MySQL pod and verify data survives
kubectl delete pod mysql-0 -n react-mysql
kubectl wait pod/mysql-0 -n react-mysql --for=condition=Ready --timeout=90s
sleep 10
curl http://myapp.local/api/user
# Expected: [{"id":1,"name":"Alice"}]  ← Alice survived pod restart

Open http://myapp.local in a browser — submit a name, it should appear in the table.

6. Troubleshooting Guide

ERROR: ImagePullBackOff or ErrImagePull

Symptom:

NAME          READY   STATUS             RESTARTS
backend-xxx   0/1     ImagePullBackOff   0

Diagnose:

kubectl describe pod -n react-mysql -l app=backend | grep -A10 "Events:"

Cause A — Image does not exist on Docker Hub:

Failed to pull image: pull access denied, repository does not exist

Fix: Build and push the images.

docker build -t subkamble/react-mysql-backend:latest ./backend
docker push subkamble/react-mysql-backend:latest
docker build -t subkamble/react-mysql-frontend:latest ./frontend
docker push subkamble/react-mysql-frontend:latest

Cause B — Docker Hub rate limit:

toomanyrequests: You have reached your pull rate limit

Fix: Pre-load images onto each node, then set imagePullPolicy: Never.

# On each cluster node (SSH in):
docker pull subkamble/react-mysql-backend:latest
docker pull subkamble/react-mysql-frontend:latest

Or use a private registry and update image references in the deployments.

Cause C — Private registry, no credentials: Create an imagePullSecret:

kubectl create secret docker-registry regcred \
  --docker-server=docker.io \
  --docker-username=<username> \
  --docker-password=<token> \
  -n react-mysql

Then add to both deployments:

spec:
  imagePullSecrets:
    - name: regcred

ERROR: mysql-0 stays Pending

Symptom:

NAME      READY   STATUS    RESTARTS
mysql-0   0/1     Pending   0

Diagnose:

kubectl describe pod mysql-0 -n react-mysql | grep -A10 "Events:"
kubectl get pvc -n react-mysql

Cause A — No StorageClass named local-path:

0/1 nodes are available: pod has unbound immediate PersistentVolumeClaims

Fix: Install the local-path provisioner (Step 4.2).

kubectl get storageclass   # local-path must be present

Cause B — WaitForFirstConsumer binding (normal behavior): The local-path StorageClass uses WaitForFirstConsumer — the PVC stays Pending until the pod is scheduled. This resolves automatically. Wait 30 seconds and check again.

Cause C — Node has insufficient disk space:

Insufficient disk space on node

Fix: Free up disk on the node or add a new node with enough space.

# Check node disk usage
kubectl describe node <node-name> | grep -A5 "Allocatable"

ERROR: Frontend crash-loops (CrashLoopBackOff)

Symptom:

NAME            READY   STATUS             RESTARTS
frontend-xxx    0/1     CrashLoopBackOff   4

Diagnose:

kubectl logs -n react-mysql -l app=frontend --previous

Cause A — Old image cached on node (stale npx serve):

npm warn exec The following package was not found and will be installed: serve@14.2.6
npm error signal SIGTERM

The node has the old Docker image (CMD: npx serve) instead of the fixed one (CMD: serve). The liveness probe kills the container before npx finishes downloading serve.

Fix:

# Check which CMD the image on the node has
# SSH into the affected node, then:
docker inspect subkamble/react-mysql-frontend:latest \
  --format='{{json .Config.Cmd}}'
# If output is ["npx","serve","-s","build"] → stale image

# Force remove and re-pull
docker rmi -f subkamble/react-mysql-frontend:latest
docker pull subkamble/react-mysql-frontend:latest

# Verify fix — output must be ["serve","-s","build"]
docker inspect subkamble/react-mysql-frontend:latest \
  --format='{{json .Config.Cmd}}'

# Then restart the pod
kubectl rollout restart deployment/frontend -n react-mysql

Cause B — Liveness probe firing too early: The container starts but port 3000 isn't bound yet when the probe fires.

Liveness probe failed: Get "http://10.x.x.x:3000/": connection refused

Fix: Increase initialDelaySeconds in k8s/base/frontend/deployment.yaml:

livenessProbe:
  httpGet:
    path: /
    port: 3000
  initialDelaySeconds: 40    # increase from 20 → 40
  periodSeconds: 20

Then re-apply:

kubectl apply -k k8s/overlays/onpremise

ERROR: Backend stays in Init:0/1

Symptom:

NAME          READY   STATUS     RESTARTS
backend-xxx   0/1     Init:0/1   0

Diagnose:

kubectl logs -n react-mysql -l app=backend -c wait-for-mysql

Cause A — MySQL readiness probe hasn't passed yet (normal for ~30s): Wait 60 seconds. The init container loops nc -z mysql 3306 until MySQL's readiness probe (mysqladmin ping) passes.

Cause B — MySQL pod is not Running:

kubectl get pods -n react-mysql -l app=mysql

Fix the MySQL pod first (see MySQL errors below), then backend will unblock.

Cause C — MySQL service DNS not resolving:

# Test from another pod
kubectl run dns-test --image=busybox:1.36 --rm -it --restart=Never \
  -n react-mysql -- nslookup mysql

Expected: resolves to the MySQL pod IP. If it fails, check the headless service:

kubectl get svc mysql -n react-mysql
# clusterIP must be "None"

ERROR: MySQL pod fails (CrashLoopBackOff)

Diagnose:

kubectl logs mysql-0 -n react-mysql

Cause A — Wrong password in secret:

[ERROR] Access denied for user 'root'@'localhost'

Fix: Verify secret.properties has matching passwords and re-apply:

cat k8s/base/secret.properties
# DB_PASSWORD, MYSQL_ROOT_PASSWORD, MYSQL_PASSWORD must all match

kubectl apply -k k8s/overlays/onpremise

Cause B — Corrupted PVC data (e.g. previous failed init):

[ERROR] InnoDB: Cannot open datafile for read-write

Fix: Delete the PVC to wipe and re-initialize:

kubectl delete statefulset mysql -n react-mysql
kubectl delete pvc mysql-data-mysql-0 -n react-mysql
kubectl apply -k k8s/overlays/onpremise

Warning: This deletes all database data.

ERROR: Ingress has no ADDRESS

Symptom:

NAME                      CLASS   HOSTS         ADDRESS   PORTS
react-mysql-api-ingress   nginx   myapp.local             80

ADDRESS column is empty after 2+ minutes.

Diagnose:

kubectl get pods -n ingress-nginx
kubectl describe ingress react-mysql-api-ingress -n react-mysql

Cause A — NGINX Ingress Controller not installed:

kubectl get pods -n ingress-nginx
# No resources found

Fix: Install it (Step 4.1).

Cause B — Ingress controller pod not Ready:

kubectl get pods -n ingress-nginx
# STATUS = Pending or CrashLoopBackOff

Fix:

kubectl describe pod -n ingress-nginx -l app.kubernetes.io/component=controller \
  | grep -A10 "Events:"

Common sub-cause: node port conflict. Check if port 80/443 is in use on the node.

Cause C — Wrong ingressClassName: The Ingress specifies ingressClassName: nginx but the controller was installed with a different class name.

kubectl get ingressclass
# NAME     CONTROLLER
# nginx    k8s.io/ingress-nginx   ← must match

If the class name differs, patch the ingress YAML or reinstall the controller.

ERROR: White/blank screen in browser

Symptom: Page loads but shows only a blank white screen. No visible errors.

Diagnose in browser: Open DevTools → Console. You'll see:

Failed to load resource: the server responded with a status of 200 (OK)
  /static/js/main.ff70bc14.js

The JS file is returning HTML instead of JavaScript.

Cause — Single Ingress with global rewrite-target: If both frontend and API paths are in one Ingress object with rewrite-target: /$2, the rewrite applies to all paths — static assets (/static/js/...) get rewritten to /, returning index.html.

Verify:

curl -si http://myapp.local/static/js/main.ff70bc14.js | head -3
# BAD:  Content-Type: text/html   ← returning index.html
# GOOD: Content-Type: application/javascript

Fix: Ensure two separate Ingress objects are used — one for /api with the rewrite annotation, one for / without:

kubectl get ingress -n react-mysql
# Must show TWO ingress objects:
# react-mysql-api-ingress      ← has rewrite-target annotation
# react-mysql-frontend-ingress ← no rewrite annotation

If only one exists, re-apply the overlay:

kubectl delete ingress -n react-mysql --all
kubectl apply -k k8s/overlays/onpremise

ERROR: curl http://myapp.local/api/user returns 404

Diagnose:

kubectl logs -n ingress-nginx -l app.kubernetes.io/component=controller | tail -20

Cause A — /api path not matching: Test the rewrite directly:

curl -si http://myapp.local/api/user
# Check X-Original-URI header in nginx logs

Cause B — Backend service unreachable:

kubectl exec -n react-mysql -l app=backend -- \
  wget -qO- localhost:3000/user

Cause C — Webhook admission error on Ingress creation:

Internal error occurred: failed calling webhook "validate.nginx.ingress.kubernetes.io"

The NGINX ingress admission webhook wasn't ready when you applied. Fix:

# Wait for ingress controller to be fully ready first
kubectl wait deployment/ingress-nginx-controller \
  -n ingress-nginx --for=condition=Available --timeout=120s

# Then re-apply
kubectl apply -k k8s/overlays/onpremise

ERROR: Data lost after MySQL pod restart

Symptom: After kubectl delete pod mysql-0, all rows are gone.

Diagnose:

kubectl get pvc -n react-mysql
# STATUS must be Bound, not Pending or Lost

Cause A — PVC is in Lost state: The underlying PersistentVolume was deleted or the node was replaced.

kubectl describe pvc mysql-data-mysql-0 -n react-mysql

This is unrecoverable without a backup. Re-initialize:

kubectl delete pvc mysql-data-mysql-0 -n react-mysql
kubectl delete pod mysql-0 -n react-mysql
# StatefulSet recreates the pod + new PVC

Cause B — Wrong StorageClass (data not actually persisted):

kubectl get pvc mysql-data-mysql-0 -n react-mysql -o jsonpath='{.spec.storageClassName}'
# Must output: local-path

If it shows standard (minikube default), the on-prem patch wasn't applied. Check the overlay is being used:

kubectl kustomize k8s/overlays/onpremise | grep storageClassName
# Must output: storageClassName: local-path

7. Updating the Application

Update backend or frontend code

# Rebuild image
docker build -t subkamble/react-mysql-backend:latest ./backend
docker push subkamble/react-mysql-backend:latest

# If nodes cache images locally, SSH into each node and force re-pull:
# docker rmi -f subkamble/react-mysql-backend:latest
# docker pull subkamble/react-mysql-backend:latest

# Rolling restart (zero downtime)
kubectl rollout restart deployment/backend -n react-mysql

# Watch rollout
kubectl rollout status deployment/backend -n react-mysql

Update ConfigMap values (non-sensitive config)

# Edit k8s/base/config.properties, then re-apply
kubectl apply -k k8s/overlays/onpremise

# Restart pods to pick up new ConfigMap
kubectl rollout restart deployment/backend deployment/frontend -n react-mysql

Update Secret values (passwords)

# Edit k8s/base/secret.properties, then re-apply
kubectl apply -k k8s/overlays/onpremise
kubectl rollout restart deployment/backend -n react-mysql

Note: Changing MYSQL_ROOT_PASSWORD after MySQL has initialized will NOT change the database password — MySQL stores it internally in the PVC. To change the DB password: exec into mysql-0 and run ALTER USER.

8. Teardown

Remove the application only (keep cluster intact)

kubectl delete namespace react-mysql

Warning: This deletes the PVC and all MySQL data permanently.

Remove NGINX Ingress Controller

helm uninstall ingress-nginx -n ingress-nginx
kubectl delete namespace ingress-nginx

Remove local-path Provisioner

kubectl delete -f https://raw.githubusercontent.com/rancher/local-path-provisioner/master/deploy/local-path-storage.yaml

9. CI/CD — Jenkins Multibranch Pipeline

This project ships with a Jenkinsfile at the repo root that automates the full build → test → push → deploy lifecycle.

9.1 Prerequisites on the Jenkins Server

Tool Purpose Install
Docker Build & push images apt install docker.io + add jenkins user to docker group
kubectl Apply k8s manifests Official install guide
kustomize Render overlays `curl -s "https://raw.githubusercontent.com/kubernetes-sigs/kustomize/master/hack/install_kustomize.sh"
NodeJS (v18+) npm ci / npm test Jenkins NodeJS plugin or system package 
# Add jenkins user to docker group (run on Jenkins host, then restart Jenkins)
sudo usermod -aG docker jenkins
sudo systemctl restart jenkins

9.2 Jenkins Plugins Required

Install via Manage Jenkins → Plugins:

Plugin Purpose
Multibranch Pipeline Detects branches + PRs automatically
Docker Pipeline Docker credential binding
Credentials Binding Injects secrets into pipeline steps
NodeJS Managed Node.js installations
Git SCM checkout

9.3 Configure Jenkins Credentials

Go to Manage Jenkins → Credentials → System → Global credentials → Add:

Credential ID Kind Fields Used for
dockerhub-credentials Username with password Username: subkamble / Password: Docker Hub PAT docker push
kubeconfig-secret Secret file Upload your ~/.kube/config kubectl cluster access

Docker Hub PAT: Generate at hub.docker.com → Account Settings → Security → New Access Token (Read/Write scope).

kubeconfig tip: If Jenkins runs inside the same cluster, use a ServiceAccount + RBAC instead of a kubeconfig file.

9.4 Create the Multibranch Pipeline Job

  1. Jenkins Dashboard → New Item
  2. Name: react-mysql → select Multibranch Pipeline → OK
  3. Under Branch Sources → Add source → Git
    • Repository URL: your repo URL
    • Credentials: add repo access if private
  4. Under Build Configuration → Mode: by Jenkinsfile → Script Path: Jenkinsfile
  5. Under Scan Multibranch Pipeline Triggers → enable Periodically if not otherwise run (e.g. every 5 min), or configure a webhook (preferred)
  6. Save → Scan Multibranch Pipeline Now

Jenkins will discover all branches and create sub-jobs automatically.

9.5 Webhook Setup (recommended — avoids polling)

GitHub:

  1. Repo → Settings → Webhooks → Add webhook
  2. Payload URL: http://<JENKINS_URL>/multibranch-webhook-trigger/invoke?token=react-mysql
  3. Content type: application/json
  4. Events: Push + Pull requests

Install the Multibranch Scan Webhook Trigger plugin on Jenkins to handle the token.

9.6 Branch Behavior Summary

Branch Build Test Push Image Deploy
main Yes Yes Yes (latest + SHA tag) k8s/overlays/onpremise (production)
staging Yes Yes Yes (branch-SHA tag) k8s/overlays/minikube (staging)
develop Yes Yes No No
feature/** Yes Yes No No
PR branches Yes Yes No No

9.7 Image Tagging Convention

Branch Tag format Example
main latest + <sha8> latest, a1b2c3d4
staging staging-<sha8> staging-a1b2c3d4
feature/login feature-login-<sha8> feature-login-a1b2c3d4

9.8 First-Run Checklist

# Verify Jenkins can reach Docker Hub
docker login -u subkamble

# Verify Jenkins can reach the cluster
kubectl get nodes

# Verify kustomize is on PATH
kustomize version

# Trigger a manual build for main branch from Jenkins UI
# then watch the Console Output for each stage

9.9 Rollback

# List available image tags (via Docker Hub API or local docker images)
docker images subkamble/react-mysql-backend

# Pin a specific tag manually and re-deploy
cd k8s/base
kustomize edit set image \
    subkamble/react-mysql-backend=subkamble/react-mysql-backend:<previous-sha> \
    subkamble/react-mysql-frontend=subkamble/react-mysql-frontend:<previous-sha>
cd -
kubectl apply -k k8s/overlays/onpremise
kubectl rollout status deployment/backend  -n react-mysql
kubectl rollout status deployment/frontend -n react-mysql

10. GitOps — ArgoCD (Reference)

The Jenkinsfile contains fully commented-out ArgoCD pipeline stages. Follow this section to activate GitOps mode.

10.1 Install ArgoCD

kubectl create namespace argocd
kubectl apply -n argocd \
  -f https://raw.githubusercontent.com/argoproj/argo-cd/stable/manifests/install.yaml

# Wait for all ArgoCD pods to be ready
kubectl wait --for=condition=Ready pods --all -n argocd --timeout=180s

# Expose the ArgoCD API server (choose one):

# Option A — Port-forward (local access only)
kubectl port-forward svc/argocd-server -n argocd 8080:443

# Option B — LoadBalancer (on-prem with MetalLB or cloud)
kubectl patch svc argocd-server -n argocd \
  -p '{"spec":{"type":"LoadBalancer"}}'

# Option C — Ingress (add argocd.myapp.local to your Ingress controller)

10.2 Get Initial Admin Password

kubectl get secret argocd-initial-admin-secret \
  -n argocd \
  -o jsonpath="{.data.password}" | base64 -d && echo

# Login
argocd login localhost:8080 --username admin --password <above-password> --insecure

# Change password immediately
argocd account update-password

10.3 Apply ArgoCD Application Manifests

Create the two Application objects (one per environment). These are documented in full inside the Jenkinsfile comments. Here is the summary of what they do:

Application Watches branch Overlay Sync policy
react-mysql-production main k8s/overlays/onpremise Automated (prune + selfHeal)
react-mysql-staging staging k8s/overlays/minikube Automated (prune + selfHeal) 
# Copy the YAML blocks from the Jenkinsfile comments into files, then:
kubectl apply -f argocd/application-production.yaml
kubectl apply -f argocd/application-staging.yaml

# Verify apps are registered
argocd app list

10.4 Jenkins Credentials for GitOps Mode

Add these alongside the existing credentials:

Credential ID Kind Purpose
argocd-auth-token Secret text ArgoCD API token for argocd app sync
gitops-ssh-key SSH username with private key Push image tag updates back to Git

Generate an ArgoCD API token:

argocd account generate-token --account admin
# Copy the output → paste as the 'argocd-auth-token' secret text

10.5 Activate GitOps in the Jenkinsfile

  1. Open Jenkinsfile
  2. Remove the active Deploy and Smoke Test stages (or leave them as fallback)
  3. Uncomment the Update GitOps Manifest and ArgoCD Sync stage blocks in the GitOps section at the bottom
  4. Replace YOUR_ARGOCD_SERVER with your ArgoCD server hostname/IP
  5. Replace YOUR_ORG in the git clone URL with your GitHub org/username
  6. Commit and push — Jenkins picks up the change automatically

10.6 GitOps Flow Diagram

Developer pushes code
        │
        ▼
   Jenkins CI
   ┌─────────────────────────────────────┐
   │ 1. npm ci → test                    │
   │ 2. docker build + push :<sha-tag>   │
   │ 3. kustomize edit set image         │
   │ 4. git commit + push [skip ci]      │
   └─────────────────┬───────────────────┘
                     │ Git push (image tag bump)
                     ▼
             Git Repository
             (k8s/base/kustomization.yaml updated)
                     │
                     │ ArgoCD polls every 3 min
                     │ (or Jenkins triggers sync via argocd CLI)
                     ▼
              ArgoCD detects drift
              ┌────────────────────────────┐
              │ kubectl apply -k overlay/  │
              │ prune removed resources    │
              │ self-heal manual changes   │
              └────────────┬───────────────┘
                           │
                           ▼
                    Kubernetes Cluster
                    (react-mysql namespace updated)

10.7 ArgoCD Quick Reference

# View app status
argocd app get react-mysql-production

# Force immediate sync (skip waiting for poll interval)
argocd app sync react-mysql-production

# Rollback to previous revision
argocd app history react-mysql-production
argocd app rollback react-mysql-production <revision-id>

# Pause auto-sync (for maintenance)
argocd app set react-mysql-production --sync-policy none

# Resume auto-sync
argocd app set react-mysql-production --sync-policy automated

# Delete app (does NOT delete k8s resources by default)
argocd app delete react-mysql-production

# Delete app AND k8s resources
argocd app delete react-mysql-production --cascade

Quick Reference Card

# Deploy
kubectl apply -k k8s/overlays/onpremise

# Check status
kubectl get pods,svc,ingress,pvc -n react-mysql

# Stream all logs
kubectl logs -n react-mysql -l app=mysql   -f
kubectl logs -n react-mysql -l app=backend -f
kubectl logs -n react-mysql -l app=frontend -f

# Debug a crashing pod
kubectl describe pod <pod-name> -n react-mysql
kubectl logs <pod-name> -n react-mysql --previous

# Test API directly (bypass ingress)
kubectl port-forward svc/backend 3000:3000 -n react-mysql
curl localhost:3000/user

# MySQL shell
kubectl exec -it mysql-0 -n react-mysql -- mysql -u root -ppass123 appdb

# Re-apply after manifest changes
kubectl apply -k k8s/overlays/onpremise

# Full teardown
kubectl delete namespace react-mysql
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