Automating Web Deployment with Ansible: A Step-by-Step Guide to Using Playbooks for Nginx

Automating Web Deployment with Ansible: A Step-by-Step Guide to Using Playbooks for Nginx

Ansible Playbook Example: Deploying a Web Application

---

- name: Deploy Web Application

  hosts: webservers

  become: yes

  vars:

    http_port: 80

    max_clients: 200

  tasks:

    - name: Install nginx web server

      apt:

        name: nginx

        state: present

        update_cache: yes

    - name: Upload the nginx configuration file

      template:

        src: templates/nginx.conf.j2

        dest: /etc/nginx/nginx.conf

      notify:

        - restart nginx

    - name: Ensure nginx is running

      service:

        name: nginx

        state: started

        enabled: true

    - name: Copy website files

      copy:

        src: /src/webfiles/

        dest: /var/www/html/

        owner: www-data

        group: www-data

        mode: 0644

  handlers:

    - name: restart nginx

      service:

        name: nginx

        state: restarted

Explanation of the Playbook:

• Hosts: Targets the webservers group, which should be defined in your inventory file.
• Become: Executes tasks with administrative (sudo) privileges.
• Vars: Defines variables for use within the playbook. http_port and max_clients can be used in configuration templates.
• Tasks:
  • Install nginx: Uses the apt module to install Nginx on Debian-based systems. Ensures the package cache is updated before installation.
  • Upload the nginx configuration file: Uses the template module to push a customized nginx configuration from a local template (nginx.conf.j2).
  • Ensure nginx is running: Ensures that the Nginx service is started and enabled to start on boot using the service module.
  • Copy website files: Transfers files from a local directory to the web server’s root directory. Sets the appropriate permissions and ownership.
• Handlers:
  • restart nginx: Defined to restart Nginx whenever the nginx configuration file changes. This is triggered by the notify directive in the template task.

This playbook is a basic example for deploying a static web application using Nginx. It demonstrates the use of modules like apt, template, service, and copy, which are commonly used in real-world scenarios to manage web servers and deploy applications. Handlers are particularly useful for restarting services only when necessary, optimizing resource usage during playbook runs.