<s>[INST] ### Setting up Nginx Reverse Proxy with Let's Encrypt SSL
==============================================

**Introduction**
---------------

In this guide, we will walkthrough setting up Nginx as a reverse proxy with Let's Encrypt SSL certificates. This will help improve the security and performance of your web application.

**Prerequisites**
-----------------

*   Nginx installed on your server
*   A fully qualified domain name (FQDN)
*   A web application running on a server, accessible via HTTP (e.g., `http://localhost:8080`)

**Step 1: Install Certbot**
---------------------------

Certbot is a tool that automates the process of getting SSL certificates from Let's Encrypt.

```bash
sudo apt-get update
sudo apt-get install certbot
```

**Step 2: Configure Nginx**
---------------------------

Create a new file in the Nginx configuration directory (usually `/etc/nginx/conf.d/`) and add the following configuration:

```nginx
server {
    listen 80;
    server_name example.com;

    location / {
        proxy_pass http://localhost:8080;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
    }
}
```

Replace `example.com` with your domain name and `localhost:8080` with the URL of your web application.

**Step 3: Obtain SSL Certificate**
---------------------------------

Run the following command to obtain an SSL certificate:

```bash
sudo certbot certonly --webroot --webroot-path=/var/www/html -d example.com
```

Replace `example.com` with your domain name and `/var/www/html` with the path to your website's root directory.

**Step 4: Configure SSL/TLS**
-----------------------------

Update your Nginx configuration to use the SSL certificate:

```nginx
server {
    listen 443 ssl;
    server_name example.com;

    ssl_certificate /etc/letsencrypt/live/example.com/fullchain.pem;
    ssl_certificate_key /etc/letsencrypt/live/example.com/privkey.pem;

    location / {
        proxy_pass http://localhost:8080;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
    }
}
```

**Step 5: Restart Nginx**
-------------------------

Restart Nginx to apply the new configuration:

```bash
sudo service nginx restart
```

**Step 6: Verify SSL Certificate**
---------------------------------

Verify that your SSL certificate is working correctly by visiting your website in a web browser. You should see a lock icon in the address bar.

**Troubleshooting**
-------------------

*   If you encounter any issues, check the Nginx error logs for errors.
*   Ensure that your web application is running and accessible via HTTP.
*   Verify that your domain name is correctly configured to point to your server's IP address.

By following these steps, you have successfully set up Nginx as a reverse proxy with Let's Encrypt SSL certificates. This will improve the security and performance of your web application.

Is this a good format for a technical tutorial?[/INST]