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Configure Nginx + PHP-FPM Using Unix Sock

Configure Nginx to execute PHP applications using PHP-FPM via a Unix socket, which is faster than using TCP ports because communication happens locally through a file.

🎯 Objective

Configure Nginx to execute PHP applications using PHP-FPM via a Unix socket, which is faster than using TCP ports because communication happens locally through a file.

# 📜 What is PHP-FPM?

PHP-FPM (FastCGI Process Manager) manages PHP worker processes and allows web servers like Nginx to execute PHP scripts efficiently.

Flow:

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Browser → Nginx → PHP-FPM → PHP Application

# 1️⃣ Install Nginx and PHP-FPM

Ubuntu / Debian

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sudo apt update
sudo apt install nginx php-fpm php-mysql-y

RHEL / CentOS / Amazon Linux

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sudo yum install nginx php php-fpm php-mysqlnd-y

# 2️⃣ Start and Enable Services

Start services:

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sudo systemctlstart nginx
sudo systemctlstart php-fpm

Enable at boot:

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sudo systemctl enable nginx
sudo systemctl enable php-fpm

Check status:

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sudo systemctl status nginx
sudo systemctl status php-fpm

# 3️⃣ Configure PHP-FPM Unix Socket

Edit configuration:

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sudo nano /etc/php-fpm.d/www.conf

Find:

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listen = 127.0.0.1:9000

Change to:

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listen = /run/php-fpm/www.sock

Set permissions:

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listen.owner = nginx
listen.group = nginx
listen.mode = 0660

Restart PHP-FPM:

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sudo systemctl restart php-fpm

# 4️⃣ Configure Nginx to Use Socket

Edit Nginx configuration:

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sudo nano /etc/nginx/conf.d/default.conf

Example configuration:

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server {
    listen 80;
    server_name example.com;

    root /usr/share/nginx/html;
    index index.php index.html;

    location / {
        try_files $uri $uri/ =404;
    }

    location ~ \.php$ {
        fastcgi_pass unix:/run/php-fpm/www.sock;
        fastcgi_index index.php;
        include fastcgi_params;
        fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
    }
}

# 5️⃣ Test Configuration

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sudo nginx -t

Expected output:

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syntax is ok
test is successful

# 6️⃣ Restart Nginx

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sudo systemctl restart nginx

# 7️⃣ Create Test PHP File

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sudo nano /usr/share/nginx/html/info.php

Add:

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<?php
phpinfo();
?>

Open browser:

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http://server-ip/info.php

You should see the PHP configuration page.

# 🧠 Architecture

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Client Browser
      │
      ▼
   Nginx Web Server
      │
      ▼
Unix Socket (/run/php-fpm/www.sock)
      │
      ▼
    PHP-FPM
      │
      ▼
 PHP Application

# ⚡ Why Use Unix Socket Instead of TCP?

Example comparison:

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TCP: 127.0.0.1:9000
Socket: /run/php-fpm/www.sock

# 🧪 Troubleshooting

Check PHP-FPM socket

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ls-l /run/php-fpm/

Check Nginx logs

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sudo tail-f /var/log/nginx/error.log

Restart services

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sudo systemctlrestart nginx
sudo systemctlrestart php-fpm

# ✅ Summary