Automating Django Todo App Deployment on AWS EC2 with Jenkins, Docker,

Preparing the Environment

1. Launch an AWS EC2 Instance

Log in to your AWS Management Console.
Navigate to EC2 and launch an instance.
SSH into your EC2 instance.

2. Install Jenkins on EC2 Instance

Install Jenkins by following the official documentation for your Linux distribution.

Note: Install Java before installing Jenkins.
After installing Jenkins, run the following commands:
```
  sudo usermod -aG docker jenkins
  sudo reboot
```
Open port 8080 in security group.

3. Install Docker and Docker Compose on EC2 Instance

  sudo apt update
  sudo apt-get install docker.io docker-compose -y
  sudo usermod -aG docker $USER
  sudo reboot

Note: After reboot, reconnect the instance.

4. Configure Jenkins

Check the status of Jenkins.
```
  sudo systemctl status jenkins
```
Open Jenkins on your EC2 instance (http://YOUR_EC2_PUBLIC_IP:8080).

Run this command to find administrator password:
```
  sudo cat /var/lib/jenkins/secrets/initialAdminPassword
```
Install necessary plugins and set up the username and password for Jenkins dashboard.

Setting Up Jenkins Pipeline

1. Create Jenkins Pipeline Job

Create a new Pipeline job in Jenkins.

New Item
Set the Git repository URL to https://github.com/robinthakur00/django-todo-app.git.

2. Define Jenkins Pipeline Stages

Create a Jenkinsfile at the root of the repository to define the deployment stages.

  pipeline {
      agent any
      stages {

          stage("Code Fetch From Git"){
              steps{
                  git url: "https://github.com/robinthakur00/django-todo-app.git", branch: "master"
              }
          }
          stage("Build Docker Image"){
              steps{
                  sh "docker build -t django-todo-app ."
              }
          }
          stage("Login And Push to DockerHub"){
              steps{
                  withCredentials([usernamePassword(credentialsId:"dockerHub",passwordVariable:"dockerHubPass",usernameVariable:"dockerHubUser")]){
                  sh "docker login -u ${env.dockerHubUser} -p ${env.dockerHubPass}"
                  sh "docker tag django-todo-app:latest ${env.dockerHubUser}/django-todo-app:latest"
                  sh "docker push ${env.dockerHubUser}/django-todo-app:latest"
                  }
              }
          }
          stage("Deploy the application"){
              steps{
                  sh "docker-compose down && docker-compose up -d"
              }
          }
      }
  }

3. Configure Jenkins Pipeline Job

Configure Jenkins pipeline job with the Jenkinsfile path (Jenkinsfile if it's at the root).
Define Docker Hub credentials in Jenkins Credentials Manager.

Go to Manage Jenkins -> Credentials -> System -> Global credentials -> Add Credentials

Running the Jenkins Pipeline

1. Trigger Jenkins Pipeline Job

Run the Jenkins pipeline job, Click Build Now
Jenkins will clone the repository, build the Docker image, push it to Docker Hub, and deploy the Django Todo App onto the EC2 instance using Docker Compose.
Access the Django Todo App in (http://YOUR_EC2_PUBLIC_IP:8000)

Note: This is a Django application that runs on port 8000. We need to open port 8000 in the security group.