DEV Community: RajarshiG

🚀 Deploying to Multiple Tomcat Instances on Windows with Jenkins — Batch Pitfalls & Service Fixes

RajarshiG — Sat, 21 Jun 2025 19:00:18 +0000

🎯 Goal

To set up a local CI/CD pipeline using Jenkins, deploying a Spring Boot WAR to two separate Tomcat 11 instances (DEV and QA) on a Windows system.

😓 Initial Issues Faced

Tomcat auto-shutdown after Jenkins build

Jenkins would invoke startup.bat, but as soon as the job finished, Tomcat shut down.
This was due to startup.bat running inside the Jenkins process and getting killed after.

Port Conflicts

Both Tomcat instances used the same default ports (8080, 8005, 8009), which prevented them from running simultaneously.

Environment variables not picked up by Spring Boot

I needed a way to inject environment-specific values (like env=DEV/QA) into Spring's @Value annotations.

🧠 Key Learnings & Fixes

✅ 1. Use Tomcat as a Windows Service

Instead of relying on startup.bat, I:

Installed TomcatDev and TomcatQA as Windows services:

cd "C:\apache-tomcat-11.0.8-DEV\bin"
service.bat install TomcatDev

cd "C:\apache-tomcat-11.0.8-QA\bin"
service.bat install TomcatQA

Used sc to control services from Jenkins:

bat 'sc stop TomcatDev && timeout /t 5 >nul && sc start TomcatDev'

This prevents Jenkins from terminating the server.

✅ 2. Customize server.xml for Each Instance

Modified these ports in conf/server.xml for both instances:

Port Type	DEV	QA
HTTP	8081	8082
Shutdown Port	8006	8007
AJP	8009	8010

Ensure they don't overlap, or services will fail silently or crash.

✅ 3. Set Environment-Specific Flags

Created a setenv.bat inside each bin/ folder:

set JAVA_OPTS=-Denv=DEV

Spring Boot picks this up with:

@Value("${env}")
private String environment;

🔧 Jenkinsfile: Deploy to Tomcat Services

Here’s a simplified Jenkins pipeline excerpt:

stage('Deploy to DEV') {
    steps {
        bat """
        sc stop TomcatDev
        timeout /t 5 >nul
        copy target\\app.war "C:\\apache-tomcat-11.0.8-DEV\\webapps\\app.war"
        sc start TomcatDev
        """
    }
}

Same pattern for QA.

💬 Final Thoughts

This debugging session taught me a lot about how Jenkins, Windows, and Tomcat interact.
If you're running Tomcat on Windows and see it die after Jenkins runs, it's probably due to how you're starting it. Using services + sc is the safest and most robust way.

🔗 LinkedIn Recap Post

If you're short on time, I shared a quick summary of this battle on LinkedIn:
👉 https://www.linkedin.com/in/rajarshig007/post

💻 CI/CD Pipeline with Jenkins, Spring Boot & Docker on Windows — No Git Bash Required

RajarshiG — Thu, 19 Jun 2025 17:40:07 +0000

I recently built a local CI/CD pipeline using Jenkins to deploy a Spring Boot application with Docker, simulating dev and QA environments. The twist? I did it entirely on Windows, using the bat command — no Git Bash or Linux dependencies!

🛠️ Stack & Tools

Jenkins (installed via Windows installer)
Spring Boot (Maven project)
Docker Compose (for dev & qa services)
GitHub (source control with PAT for authentication)
Windows batch scripts (bat) for Jenkins steps

🔄 Pipeline Overview

My Jenkins pipeline does the following:

Pulls code from GitHub (set to main branch manually)
Builds the Spring Boot app using:

   dir('backend') {
     bat 'mvnw.cmd clean package -DskipTests'
   }

Builds Docker images for both dev and QA
Deploys the dev container
Adds a manual input step before proceeding to QA deployment

🧪 Environments Setup with Docker Compose

Here’s a snapshot from my docker-compose.yml:

services:
  backend-dev:
    build: ./backend
    ports:
      - "8082:8080"
    environment:
      - SPRING_PROFILES_ACTIVE=dev

  backend-qa:
    build: ./backend
    ports:
      - "8083:8080"
    environment:
      - SPRING_PROFILES_ACTIVE=qa

Each profile (application-dev.properties, application-qa.properties) gets picked up based on SPRING_PROFILES_ACTIVE.

⚠️ What I Learned

Jenkins on Windows uses bat, not sh
Use mvnw.cmd instead of ./mvnw
Make sure the backend directory exists in your GitHub repo, or Jenkins will break
GitHub no longer supports password auth — use a Personal Access Token
Docker COPY target/*.jar fails if the app isn’t built first!

✅ Next Goals

Add frontend (React)
Push images to GitHub Container Registry
Setup GitHub webhook to auto-trigger Jenkins

💬 Final Thoughts

This was my first fully local pipeline and it’s taught me more than any tutorial could. If you’re starting with Jenkins, don’t be afraid to break things — just read the logs carefully and keep experimenting.

Feel free to connect if you're working on something similar!

#Jenkins #SpringBoot #DevOps #Docker #CI_CD #Java #WindowsDeveloper #Tutorial #BuildInPublic

From Chaos to Deployment: Fixing Cross-Origin Auth in React + Spring Boot (My 3-Day 401 Debug Story)

RajarshiG — Tue, 17 Jun 2025 17:46:29 +0000

I recently finished building a full-stack Library Management System, with:

🖥️ Frontend in React, deployed on Vercel
🔧 Backend in Spring Boot, deployed on Railway

At the start, I was excited. But then... deployment hit me like a wall.

🧩 The Struggles

I didn't know:

How to deploy the backend and frontend separately
How to set up CORS and cookies properly
Why my app worked in Firefox, but failed with 401 errors in Chrome

I tried debugging:

Spring Security
Session management
Axios headers and cookies

I even rewrote parts of my code, thinking the problem was in my auth flow…

Turns out, Chrome had third-party cookies disabled. 😤

Three. Days. Gone.

🔐 What I Learned

Spring Security from Scratch

I learned how to create a SecurityFilterChain and handle login with session-based auth using a custom success handler.
Backend over LocalStorage

Initially, I was storing the user in localStorage and using it for validation.

I later replaced this with a backend call to /check-auth, making it more secure and reliable.
CORS + Cookie Configuration

   .allowedOrigins("https://my-frontend.vercel.app")
   .allowCredentials(true)

Axios:

withCredentials: true

Cookie Headers

SameSite=None
Secure
HttpOnly

All crucial for cross-origin session persistence.

✅ Final Setup

🌐 Frontend: React + Vercel
🔧 Backend: Spring Boot + Railway
🔐 Auth: Session-based, cookie-secured
🧠 Learned: Spring Security, Session Auth, CORS, Deployment practices

🎯 Next Goal

Now that it’s stable, I’m planning to migrate the backend to AWS EC2 for a more production-like deployment.

Wish me luck 🤞

If you’ve ever been stuck debugging for days over something silly — you’re not alone. Keep going. It clicks eventually ✨

#SpringBoot #ReactJS #WebDev #FullStack #SpringSecurity #Debugging #AWS #DevJourney