Hands-On Setup NginX with Ansible

I will do hands-on Ansible with this project.

Project Challange

1. Siapkan 3 server untuk ansible di virtualbox, 1 Control Node dan 2 Managed Node
2. Install Ansible di Control Node

Notes

I change the project to use 3 VM in GCP, 1 Control Node and 2 Managed Node

Overview

I have master-node here as control node and server-1 and server-2 as managed node. Master node will be used to install Ansible and run the playbook. server-1 and server-2 will be used to setup nginx.

Setup VM Instance in GCP

List of VM instances created in GCP.

Successfully ssh into 3 VM instances in GCP.

	master-node	server-1	server-2
Internal IP	10.148.0.4	10.148.0.2	10.148.0.3
External IP	34.142.170.66	34.87.138.115	35.240.209.141
OS	Ubuntu 24.04 LTS	Ubuntu 24.04 LTS	Ubuntu 24.04 LTS
Network	Allow HTTP	Allow HTTP	Allow HTTP

Setup Powerless SSH

Generate SSH Key on Master Node:

ssh-keygen -t rsa -b 4096
cat ~/.ssh/id_rsa.pub

Paste the Public Key to GCP Metadata SSH Keys:

Copy the public key to your clipboard and paste it in the GCP Metadata SSH Keys (like the image below).

Setup passwordless SSH by generating SSH key on master node and registering the public key to Metadata Compute Engine on GCP.

Success Setup Passwordless SSH

Now master-node can SSH to server-1 and server-2 without password

Introduction to Ansible

Ansible is open-source automation tool that can be used to manage configuration, deploy applications, and run tasks on single or multiple servers. The way it works is by using SSH to connect to the target servers and execute tasks defined in a playbook.

There are several key concepts in Ansible that you need to understand before getting started:

• Inventory: A file that contains a list of servers to be managed by Ansible. This file can be in INI or YAML format.
• Playbook: A YAML file that defines the tasks to be executed on the target servers. Playbooks are the heart of Ansible automation.
• Module: A script that performs a specific task (e.g., installing a package or managing a service). Ansible has many built-in modules that you can use in your playbooks.

Setup Ansible on Master Node

Steps:

1. Update Package List:
   

   sudo apt update
   

2. Install Ansible:

   sudo apt install ansible -y
   

3. Check Ansible Version:

   ansible --version
   
   # or
   
   command -v ansible
   

Create Inventory and Playbook

# Project Structure
~/ansible/
├── inventory.ini
└── playbook/
    └── install_nginx.yml

Inventory File

Inventory file is a file that contains a list of servers to be managed by Ansible. This file can be in INI or YAML format. In this example, we will use the INI format.

[servers]
server1 ansible_host=10.148.0.2
server2 ansible_host=10.148.0.3

Details .ini file

• [servers]: This is a group name that contains the servers you want to manage.
• server1 ansible_host=...: This line defines a server in the group. server1 is the alias you will use in your playbook, and ansible_host is the actual IP address of the server.

Playbook File

---
- name: Install Nginx and Setup HTML Page
  hosts: servers
  become: yes
  tasks:
    - name: Update apt cache
      apt:
        update_cache: yes

    - name: Install Nginx
      apt:
        name: nginx
        state: present

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

    - name: Get server IP address
      command: hostname -I
      register: server_ip
      changed_when: false

    - name: Create index.html with Hello World and IP
      copy:
        content: "<h1>Hello World from {{ inventory_hostname }}</h1><p>Server IP: {{ server_ip.stdout }}</p>"
        dest: /var/www/html/index.html
        mode: '0644'

Details setup_nginx.yml file

Playbook Header

---
- name: Install Nginx and Setup HTML Page
  hosts: servers
  become: yes

• Purpose: Defines the playbook and its target

• Components:

  • name: Playbook title for identification
  • hosts: Targets the "servers" group from inventory file
  • become: yes: Grants sudo privileges for all tasks

---

Tasks Section

Task 1: Update APT Cache

- name: Update apt cache
  apt:
    update_cache: yes

• Purpose: Refreshes the package manager's cache

• Module: apt

• Parameters:

  • update_cache: yes: Triggers refresh of APT package lists

Task 2: Install Nginx

- name: Install Nginx
  apt:
    name: nginx
    state: present

• Purpose: Installs Nginx web server
• Module: apt
• Parameters:
  • name: nginx: Specifies the package to install
  • state: present: Ensures Nginx is installed (won’t remove if already present)

Task 3: Start and Enable Nginx

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

• Purpose: Configures Nginx service
• Module: service
• Parameters:
  • name: nginx: Targets the Nginx service
  • state: started: Ensures Nginx is running now
  • enabled: yes: Makes Nginx start automatically on boot

Task 4: Get Server IP Address

- name: Get server IP address
  command: hostname -I
  register: server_ip
  changed_when: false

• Purpose: Retrieves server's IP address
• Module: command
• Parameters:
  • hostname -I: Runs command to get IP(s)
  • register: server_ip: Saves output to server_ip variable
  • changed_when: false: Marks task as not changing system state

Task 5: Create Custom HTML Page

- name: Create index.html with Hello World and IP
  copy:
    content: "<h1>Hello World from {{ inventory_hostname }}</h1><p>Server IP: {{ server_ip.stdout }}</p>"
    dest: /var/www/html/index.html
    mode: '0644'

• Purpose: Creates Nginx welcome page
• Module: copy
• Parameters:
  • content: Defines HTML with dynamic values:
    • {{ inventory_hostname }}: Inserts server’s hostname
    • {{ server_ip.stdout }}: Inserts IP from Task 4
  • dest: /var/www/html/index.html: Sets file path for HTML
  • mode: '0644': Sets permissions (read/write for owner, read for others)

Workflow Summary

1. Refreshes package cache
2. Installs Nginx
3. Starts Nginx and enables it on boot
4. Captures server IP
5. Creates HTML page with hostname and IP

---

Run the Playbook

Now it's time to run the automation!

Steps:

1. Ensure You Are in the Ansible Directory:
   

   cd ~/ansible/
   

2. Ping the Servers:

   ansible -i inventory.ini servers -m ping
   

   This command checks if Ansible can connect to the servers. If successful, you will see a "pong" response.

   

   Picture show that ansible can connect to the servers and get a pong response.

3. Run the Playbook:
   

   ansible-playbook -i inventory.ini playbook/install_nginx.yml
   

   

   The picture show that ansible can connect to the servers and run the playbook to install nginx.

   master-node (left) successfully run the playbook to install nginx on server1 (left) and server2 (middle). I running curl http://localhost to managed node to check if nginx is running and successfully return the HTML page created by the playbook.

---

Verify the Nginx Installation

Steps:

1. Open a Web Browser:

   • Go to http://<server1_external_ip> and http://<server2_external_ip>.
   • You should see the "Hello World" message with the server's IP address.

   

   Successfully open the web browser and see the Hello World message with the server's IP address.

2. Check Nginx Status:

   ssh muhammadagfian96@10.48.0.2
   curl http://localhost
   

   • This command checks if Nginx is running on server1.

What's Next?

Learning Ansible is a great way to automate tasks and manage configurations. You can explore more advanced features like roles, templates, and dynamic inventories to enhance your automation skills.

Ansible Galaxy

Ansible Galaxy is an online platform provided by the Ansible community to share automation content like roles and collections. It’s like an "app store" for Ansible, where you can find and download pre-built code for specific tasks, such as installing Docker.

• Roles: A bundle of tasks, variables, and files packaged to perform a specific function, like installing Nginx.
• Collections: Larger packages that can include multiple roles, modules, or plugins for more complex needs.

Example: Steps to Install Docker Collection

1. Install Ansible Galaxy:
   

   ansible-galaxy collection install community.docker
   

2. Verify Installation:
   

   ansible-galaxy collection list
   

3. Create a Playbook:
   

   ---
   - name: Install Specific Docker Version
     hosts: servers
     become: yes
     tasks:
       - name: Install Docker 20.10
         community.docker.docker_host:
           state: present
           version: "20.10"
   

   Details install_docker.yml file

   • hosts: servers: Target the "servers" group.
   • become: yes: Use sudo.
   • Task:
     • Module: community.docker.docker_host. So it means that this module is from the community.docker collection. We don't need to manually install from scratch.
     • Parameters:
       • state: present: Ensure Docker is installed.
       • version: "20.10": Specify the Docker version (change as needed, e.g., "24.0").

4. Run the Playbook:
   

   ansible-playbook -i inventory.ini playbook/install_docker.yml
   

Why use Ansible Galaxy?

• Saves time since we don’t need to write code from scratch.
• Community-supported, so the code is usually tested and reliable.

Conclusion

In this project, i learned how to set up Ansible, create an inventory file and playbook, and run the playbook to install Nginx on multiple servers. I also learned about Ansible Galaxy and how to use it to install Docker.

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