How to Set Up Nginx as a Reverse Proxy Server for PM2 on AlmaLinux 9

To set up Nginx as a reverse proxy server for PM2 on AlmaLinux 9, follow these steps:

Step 1 : Update the System

Run the following command to update your system packages:

sudo dnf update -y

Step 2 : Install Nginx

Install Nginx using:

sudo dnf install nginx -y

Step 3 : Configure Firewall

Allow HTTP and HTTPS traffic through the firewall:

sudo firewall-cmd --permanent --add-service=http
sudo firewall-cmd --permanent --add-service=https
sudo firewall-cmd --reload

Step 4 : Create a New Nginx Configuration for Your App

Create a new configuration file for your application (replace example.com with your actual domain):

sudo nano /etc/nginx/conf.d/example.com.conf

Add the following content:

server {
    listen 80;
    server_name example.com www.example.com;

    location / {
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header Host $http_host;
        
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection "upgrade";
        
        proxy_pass http://localhost:3000;
        proxy_redirect off;
        proxy_read_timeout 240s;
    }
}

Save and exit (CTRL + X, then Y and ENTER).

Step 5 : Test Nginx Configuration

Run the following command to check for syntax errors:

sudo nginx -t

If everything is correct, you will see a confirmation message.

Step 6 : Restart Nginx

Apply the changes by restarting Nginx:

sudo systemctl restart nginx
sudo systemctl enable nginx

Step 7 : Configure SELinux (If Enabled)

If SELinux is enabled, allow Nginx to connect to the application running on PM2:

sudo setsebool -P httpd_can_network_connect true

Step 8 : Verify the Setup

Open your browser and visit http://example.com. If everything is set up correctly, you should see your application running.

Congratulations! You have successfully set up Nginx as a reverse proxy for PM2 on AlmaLinux 9.