Day 59 - Deploying a Web App with Ansible 🚀

Introduction
Automation simplifies complex tasks, and Ansible is a shining star in the automation space. Today, let's embark on a hands-on project: deploying a simple web app using Ansible. By the end of this task, you'll learn how to create EC2 instances, set up Ansible, and deploy a web application—all with seamless automation.

What You’ll Learn

This blog walks you through deploying a sample web application using Ansible. Here's a snapshot of what we’ll do:

Set up three EC2 instances on AWS.
Configure Ansible on the host server.
Use an Ansible playbook to install Nginx and deploy a sample webpage.

Whether you're a DevOps enthusiast or a beginner exploring automation, this guide offers detailed, actionable steps.

Step-by-Step Guide to Deploying a Web App

Task 01: Set Up EC2 Instances

Create Three EC2 Instances:
- Launch three AWS EC2 instances with the same Key Pair for SSH access.
- Use the Ubuntu image for consistency.

Command Example (AWS CLI):

    aws ec2 run-instances \
      --image-id ami-12345678 \
      --count 3 \
      --instance-type t2.micro \
      --key-name your-key-pair \
      --security-group-ids sg-12345678 \
      --subnet-id subnet-12345678

Pro Tip: Ensure the security group allows SSH (port 22) and HTTP (port 80) access.

Identify the Instances:
- Note down the public IPs of your instances for configuring Ansible.

Task 02: Set Up the Ansible Host Server

Install Ansible on the Host Server:
- SSH into your host server and install Ansible.
- For Ubuntu, use:
```
  sudo apt update
  sudo apt install ansible -y
```
Transfer the Private Key:
- Copy your EC2 Key Pair file to the host server for seamless SSH access to the instances.

Command Example (From Local to Host Server):

    scp -i your-key.pem your-key.pem ubuntu@host-server-ip:/home/ubuntu/.ssh/

Set Permissions:

 chmod 600 /home/ubuntu/.ssh/your-key.pem

Task 03: Configure Ansible Inventory

Edit the Inventory File:

Open the inventory file to add the IPs of your EC2 instances.
```
  sudo vim /etc/ansible/hosts
```

Add the following content:

  [webservers]
  instance1 ansible_host=<public-ip-1> ansible_user=ubuntu ansible_ssh_private_key_file=/home/ubuntu/.ssh/your-key.pem
  instance2 ansible_host=<public-ip-2> ansible_user=ubuntu ansible_ssh_private_key_file=/home/ubuntu/.ssh/your-key.pem
  instance3 ansible_host=<public-ip-3> ansible_user=ubuntu ansible_ssh_private_key_file=/home/ubuntu/.ssh/your-key.pem

Test Connectivity:
```
 ansible -m ping all
```
- If successful, you'll see a "pong" response for all instances.

Task 04: Write and Execute an Ansible Playbook

Create the Playbook File:
- Use a YAML file to define your Ansible playbook:
```
  sudo vim nginx_webapp.yml
```

Sample Playbook Content:

    ---
    - name: Deploy Nginx and a Sample Web Page
      hosts: webservers
      become: true
      tasks:
        - name: Install Nginx
          apt:
            name: nginx
            state: present
            update_cache: yes

        - name: Start and enable Nginx
          service:
            name: nginx
            state: started
            enabled: yes

        - name: Deploy sample HTML page
          copy:
            content: "<h1>Welcome to My Ansible Web App!</h1>"
            dest: /var/www/html/index.html

Run the Playbook:
```
 ansible-playbook nginx_webapp.yml
```

Why This Project Matters

Hands-On Learning: Gain practical experience with Ansible by configuring servers and deploying a web app.
Automation Expertise: Understand how to automate repetitive server management tasks.
Scalability: Learn how Ansible simplifies managing multiple servers in a distributed environment.

Final Thoughts

This project is a stepping stone for mastering Ansible and server automation. As you successfully deploy the web app, you’ll appreciate how much time and effort automation tools like Ansible save in real-world scenarios.