Guide: Create a Subdomain on Ubuntu + Apache + Certbot

0) Before you start

• You need a VPS with Apache installed and running.
• You need access to the domain DNS (Hostinger panel).
• Use your normal user (e.g., daniel) and run admin actions with sudo (recommended).

✅ Good practice: work as a regular user with sudo, not as root.

1) Create the DNS record (Hostinger panel)

Create an A record:

• Name/Host: subdomain
• Type: A
• Value: <YOUR_VPS_PUBLIC_IP>
• TTL: default is fine

⏳ Note: DNS propagation can take minutes (sometimes longer).

2) Deploy your site files

Recommended path pattern on Ubuntu:

/var/www/subdomain/public

2.1 Create folders + permissions

sudo mkdir -p /var/www/subdomain/public
sudo chown -R daniel:www-data /var/www/subdomain
sudo chmod -R 2755 /var/www/subdomain

2.2 Copy or clone your repo

Option A: copy from an existing clone:

rsync -av --delete ~/path/to/repo/ /var/www/subdomain/public/

Option B: clone directly into /var/www:

cd /var/www/subdomain
git clone <REPO_URL> public
sudo chown -R daniel:www-data /var/www/subdomain

2.3 Confirm you have an entry point

ls -la /var/www/subdomain/public
# You should see index.html (or your main HTML file)

3) Configure Apache (HTTP / port 80)

Create a new VirtualHost file:

sudo nano /etc/apache2/sites-available/subdomain.conf

Paste this (update domain + paths):

<VirtualHost *:80>
    ServerName subdomain.seriousdesign.net

    DocumentRoot /var/www/subdomain/public

    <Directory /var/www/subdomain/public>
        Options Indexes FollowSymLinks
        AllowOverride All
        Require all granted
    </Directory>

    ErrorLog ${APACHE_LOG_DIR}/subdomain_error.log
    CustomLog ${APACHE_LOG_DIR}/subdomain_access.log combined
</VirtualHost>

3.1 Enable the site + reload

sudo a2ensite subdomain.conf
sudo apache2ctl configtest
sudo systemctl reload apache2

✅ Expected: apache2ctl configtest returns Syntax OK.

3.2 Optional: disable the default site

If you don’t want Apache to ever serve the default placeholder site:

sudo a2dissite 000-default.conf
sudo systemctl reload apache2

4) Verify routing & DNS

4.1 Confirm DNS resolves on the server

getent hosts subdomain.seriousdesign.net

✅ Expected: it returns an IP address (your VPS IP).

4.2 Confirm Apache sees your vhost

sudo apache2ctl -S

✅ Expected: a line like port 80 namevhost subdomain.seriousdesign.net (.../subdomain.conf:1)

4.3 Test HTTP response

curl -I http://subdomain.seriousdesign.net

5) Enable HTTPS (Certbot + Apache plugin)

5.1 Confirm Certbot is installed

certbot --version

5.2 Request certificate and auto-configure Apache

sudo certbot --apache -d subdomain.seriousdesign.net

When prompted, choose the option to redirect HTTP → HTTPS (recommended).

5.3 Reload and confirm your HTTPS vhost exists

sudo systemctl reload apache2
sudo apache2ctl -S | grep -E "subdomain\.seriousdesign\.net|:443"

5.4 Test HTTPS response

curl -I https://subdomain.seriousdesign.net

6) Confirm auto-renewal

sudo certbot renew --dry-run

✅ Expected: renewal simulation succeeds (no errors).

7) Troubleshooting checklist

• DNS not ready: getent hosts subdomain.seriousdesign.net shows wrong IP or nothing.
• Apache vhost not loaded: check /etc/apache2/sites-enabled/ and run sudo apache2ctl -S.
• Syntax errors: run sudo apache2ctl configtest.
• Check logs:

  sudo tail -n 100 /var/log/apache2/subdomain_error.log
  sudo tail -n 100 /var/log/apache2/subdomain_access.log

Appendix: What these commands mean (quick)

• lsb_release -a → shows Ubuntu distribution/version (helps match correct docs).
• apache2 -v → shows Apache version/build (directive compatibility).
• apache2ctl -S → shows loaded vhosts and which is default per port (routing table).
• a2dissite 000-default.conf → disables the default catch-all site (optional, often recommended).