Linux: Web Servers and Core Services

# Write the config file
sudo tee /etc/nginx/sites-available/app.example.com > /dev/null <<'CONF'
server {
    listen 80;
    server_name app.example.com;

    location / {
        proxy_pass http://127.0.0.1:3000;
        proxy_http_version 1.1;

        # Forward real client identifiers to backend service
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection 'upgrade';
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto $scheme;

        proxy_cache_bypass $http_upgrade;
    }
}
CONF

# Enable site configuration and apply changes
sudo ln -s /etc/nginx/sites-available/app.example.com /etc/nginx/sites-enabled/
sudo nginx -t && sudo systemctl reload nginx

# Write the config file
sudo tee /etc/apache2/sites-available/example.conf > /dev/null <<'CONF'
<VirtualHost *:80>
    ServerName example.com
    ServerAlias www.example.com
    DocumentRoot /var/www/example/html

    <Directory /var/www/example/html>
        Options -Indexes +FollowSymLinks
        AllowOverride All
        Require all granted
    </Directory>

    ErrorLog ${APACHE_LOG_DIR}/example_error.log
    CustomLog ${APACHE_LOG_DIR}/example_access.log combined
</VirtualHost>
CONF

# Enable virtual host and reload service
sudo a2ensite example.conf
sudo apachectl configtest && sudo systemctl reload apache2

# PostgreSQL: Create database and application user
sudo -u postgres psql -c "CREATE DATABASE prod_db;"
sudo -u postgres psql -c "CREATE USER appuser WITH ENCRYPTED PASSWORD 'secret';"
sudo -u postgres psql -c "GRANT ALL PRIVILEGES ON DATABASE prod_db TO appuser;"

# MariaDB: Run baseline security hardening script
sudo mysql_secure_installation

# NFS Server setup in /etc/exports:
# /srv/shared_data 192.168.1.0/24(rw,sync,no_subtree_check)

# Export all shares defined in /etc/exports
sudo exportfs -arv

# Client mount command
sudo mount -t nfs 192.168.1.10:/srv/shared_data /mnt/nfs