# --- Setup Java Project ---
mkdir jenkins-demo
cd jenkins-demo

# Create Hello.java
nano Hello.java
# Add this inside:
 public class Hello {
    public static void main(String[] args) {
         System.out.println("Hello Jenkins");
    }
 }

# --- Initialize Git ---
git init
git add .
git commit -m "Initial commit - Hello Jenkins"

# --- Connect to GitHub ---
git remote add origin <repository_URL>
git branch -M main
git push -u origin main

# --- Configure Jenkins ---
# 1. Open Jenkins Dashboard
# 2. Click "New Item" → Choose "Freestyle project"
# 3. Under "Source Code Management", select Git
# 4. Add repository URL and credentials

# --- Define Build Steps ---
echo "Building Java Project..."
javac Hello.java
echo "Running Project..."
java Hello

# --- Run Jenkins Job ---
# Click "Build Now"
# Jenkins console output:
# Building Java Project...
# Running Project...
# Hello Jenkins
# Finished: SUCCESS


6. # --- Install and setup Docker ---
sudo apt install docker.io -y
docker --version

sudo systemctl start docker
sudo systemctl enable docker
sudo systemctl status docker

sudo docker run hello-world

# --- Manage images ---
docker pull nginx
docker images


# --- Build custom image ---
nano Dockerfile
sudo docker build -t myapp .

# --- Run containers ---
docker run -d -p 8080:80 myapp
docker ps
docker ps -a

# --- Manage containers ---
docker stop <container_id>
docker start <container_id>
docker restart <container_id>
docker rm <container_id>
docker logs <container_id>

sudo docker run hello-world
sudo docker ps -a
sudo docker info
sudo docker start <id>
sudo docker run -d <image name>


7.


# 1. Create project folder
mkdir registration-form
cd registration-form

# 2. Start Docker service
sudo systemctl start docker
sudo systemctl enable docker
sudo systemctl status docker

# 3. Pull NGINX image
sudo docker pull nginx
sudo docker images

# 4. Create HTML file
nano register.html
# (Add your HTML form and save)

# 5. Create Dockerfile
nano Dockerfile
# Add:
FROM nginx:latest
COPY register.html /usr/share/nginx/html/index.html

# 6. Build Docker image
sudo docker build -t registrationform .

# 7. Run container
sudo docker run -d -p 8080:80 registrationform

# 8. Check running container
sudo docker ps

# 9. Open in browser
# Visit http://localhost:8080



7. (alternative)
Install Docker:

1. sudo apt update


2. sudo apt install docker.io -y



Start Docker:
3. sudo systemctl start docker
4. sudo systemctl enable docker
5. docker --version

Test Docker is working:
sudo docker run hello-world

★ Create a Simple Docker App

Create folder:
mkdir mydockerapp
cd mydockerapp

Create a Python file:
nano app.py
print("Hello from Docker!")
(Ctrl + S, Ctrl + X to save and exit)

Create Dockerfile:
nano Dockerfile
FROM python
COPY app.py .
CMD ["python", "app.py"]
(Ctrl + S, Ctrl + X to save and exit)

Build the Docker image:
sudo docker build -t myapp .

Run the container:
sudo docker run myapp

Output:
Hello from Docker!