Node.js Application with Jenkins

Why Node.js is missing

Jenkins runs inside a Docker container. The official jenkins/jenkins:lts image does not include Node.js. If your Execute Shell runs npm install, you get npm: not found.

You must either:

1. Install Node.js inside the container (fine for learning), or
2. Use a Docker-based agent / custom image (preferred later)

This lesson uses option 1 so Freestyle stays simple.

Step 1 — Recreate Jenkins with port 3001 (if needed)

If you already exposed 3001 on Day 1, skip stop/rm. Otherwise:

docker stop jenkins
docker rm jenkins
 
docker run -d \
  --name jenkins \
  -p 8080:8080 \
  -p 50000:50000 \
  -p 3001:3001 \
  -v jenkins_home:/var/jenkins_home \
  jenkins/jenkins:lts

The jenkins_home volume keeps your jobs and plugins.

Step 2 — Install Node.js inside the Jenkins container

docker exec -u root -it jenkins bash

Inside the container:

apt update
apt install nodejs npm -y
node -v
npm -v
exit

Step 3 — Install PM2 on the EC2 host (optional pattern)

In this lab, PM2 often runs inside the Jenkins container so the Freestyle shell can call pm2 during the build. Install it where your build steps run:

docker exec -u root -it jenkins bash
npm install -g pm2
exit

Step 4 — Update the Freestyle Execute Shell

Edit my-first-job (or a new Freestyle job pointing at the same repo). Replace the shell with:

export PATH=$PATH:/usr/local/bin
 
echo "Build started!"
echo "Branch: $GIT_BRANCH"
echo "Build Number: $BUILD_NUMBER"
 
echo "Listing files..."
ls -la
 
echo "Navigating to project folder..."
cd project-1-freestyle
 
echo "Installing dependencies..."
npm install
 
echo "Running tests..."
npm test
 
echo "Build completed successfully!"
 
echo "Deploying app using PM2..."
 
if pm2 list | grep -q project-1-app; then
  echo "App exists → Restarting..."
  pm2 restart project-1-app
else
  echo "App not found → Starting..."
  pm2 start index.js --name project-1-app
fi
 
pm2 save

Save → Build Now → open Console Output.

You should see npm install, tests, and a PM2 start/restart.