Ravindra BagaleCourses & study guides मराठी Track your progress

12. Domains and DNS: GoDaddy, Elastic IP, A/CNAME and Subdomains

12.5 Configuring the Web Server for the Domain

By Last updated:

Also in the AWS course: this lesson is the same as 9.8 Configure the web server for the domain in the AWS course, which is the main version of this page.

DNS visitor la tumchya IP var aanto; aata web server la te naav olakhayla pahije.

# Nginx: /etc/nginx/conf.d/example.conf  (Ubuntu: sites-available/example + symlink)
server {
    listen 80;
    listen [::]:80;
    server_name example.com www.example.com;
    root /var/www/example;
    index index.html;
    location / { try_files $uri $uri/ =404; }
}

# Apache: /etc/httpd/conf.d/example.conf  (Ubuntu: sites-available/example.conf + a2ensite)
<VirtualHost *:80>
    ServerName  example.com
    ServerAlias www.example.com
    DocumentRoot /var/www/example
    <Directory /var/www/example>
        Require all granted
    </Directory>
</VirtualHost>

sudo mkdir -p /var/www/example && echo '<h1>example.com is live!</h1>' | sudo tee /var/www/example/index.html
sudo nginx -t && sudo service nginx reload                  # Nginx
sudo apachectl configtest && sudo service httpd reload      # Apache AL2023/CentOS
sudo apache2ctl configtest && sudo service apache2 reload   # Apache Ubuntu
curl -I http://example.com

If you had put the public IP in server_name in Chapter 8, replace it with the domain names now.

Ravindra Bagale's Tip

The domain is working but the welcome page shows – because the domain isn't in server_name. Many students write only example.com and forget www. Write both names: server_name yourdomain.com www.yourdomain.com;.

Lab

Create /var/www/yourdomain, add the server block or virtual host, test, reload and open the domain in a browser.

Extended teaching notes

Why this lesson matters

Use this lesson to strengthen systems you own: understand the risk, practise safely in a lab, then write and apply the fix.

Apply the fix across stacks

Same class of bug, same idea in every language.

Java / Spring Boot

Parameterise queries, encode output, CSRF tokens, limited Actuator, dependency scanning.

ASP.NET Core

EF Core / parameterised SQL, Razor encoding, HTTPS, Data Protection.

Node.js / Express

helmet, parameterised SQL, npm audit, avoid eval and shell concat.

Python / Django / Flask / FastAPI

ORM, autoescape, pip-audit, Bandit; never shell=True with user input.

PHP / Laravel

PDO/Eloquent, Blade escaping, composer audit.

Go / Ruby

database/sql placeholders / ActiveRecord; html/template / ERB escaping; govulncheck / Brakeman.

nginx / Apache / Tomcat

Hide versions, TLS, security headers, least-open ports.

MySQL / PostgreSQL / MongoDB / Redis

Private networks, auth on, least-privilege users, no 0.0.0.0/0.

AWS / Azure / GCP

Roles not long-lived keys, private data stores, cloud audit logs on.

Mini case study

Suppose we are on a purple-team exercise for an Indian mid-size company (sample data). Red notes a technique from this lesson against a lab clone. Blue must show the control that stops it, the log that would have fired, and the ticket that hardens production. That is the standard this course trains you for.

Defender's worksheet (do this today)

  1. Write the lesson title, date and the exact lab target you are allowed to use.
  2. List three owned systems (VMs, apps, or cloud accounts) where this lesson applies.
  3. Run one safe check from the lesson on a lab system only. Paste the command and output.
  4. Write a two-sentence fix you would give a teammate.
  5. Name one related public advisory (CERT-In, CISA, NVD, or a vendor bulletin) with its date.

Indian workplace (sample data)

Suppose we are a junior analyst at Infosys, TCS, Wipro or a fintech SOC in Bengaluru/Pune. Turn this lesson into one checklist item with an owner, a due date and a place to store evidence (ticket + screenshot).

Global practice

Compare your notes with OWASP, CIS Benchmarks, NIST CSF/IR guidance or a cloud Well-Architected security question. Write five lines on what overlaps.

Everyday analogy

Explain the risk and the fix to a family member without jargon. If they can repeat the warning, you understand it well enough to teach juniors.

Key terms

  • Control: a safeguard (patch, config, process, detection).
  • Finding: a weakness backed by evidence.
  • Remediation: the fix plus how you verified it.
  • Scope: systems you have written permission to touch.
  • Least privilege: only the access the task needs.
  • Defence in depth: several layers so one failure does not end the story.

Common mistakes

  • Skipping written permission "just for a quick scan".
  • Practising on hostel, office or public targets without authorisation.
  • Collecting tool output without writing the fix.
  • Copying attack steps onto production to "verify". Defenders verify with versions, configs and patches.
  • Publishing screenshots that contain secrets, cookies or internal hostnames.

Recap

  • Evidence, fix, owner, date.
  • Own lab only.
  • Fix > spectacle.