[FIXED] Error Certbot 'Failed authorization procedure (http-01)'

🚀 Step-by-Step Fixes

Step 1: Verify Port 80 Accessibility

Let's Encrypt strictly requires port 80 to be accessible over the public internet to validate domain ownership via the http-01 challenge, even if your site redirects traffic to HTTPS (port 443).

1. Firewall Settings (UFW):
   BASH Copy

   sudo ufw allow 80/tcp
   sudo ufw allow 443/tcp
   sudo ufw reload
   

2. Cloud Security Groups (AWS / GCP / Proxmox): Ensure your cloud security rules permit inbound traffic on port 80 from 0.0.0.0/0.

Step 2: Configure ACME Challenge Location in Nginx

If Nginx is active, ensure the server block explicitly grants access to the hidden .well-known/acme-challenge/ directory:

Edit /etc/nginx/sites-available/yourdomain.conf:

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

    location /.well-known/acme-challenge/ {
        root /var/www/html;
        allow all;
    }

    location / {
        return 301 https://$host$request_uri;
    }
}

Test and reload Nginx:

sudo nginx -t && sudo systemctl restart nginx

Step 3: Issue via Standalone Mode

If web server routing interferes with token verification, temporarily stop your web server and run Certbot in standalone mode:

# 1. Stop web server
sudo systemctl stop nginx || sudo systemctl stop apache2

# 2. Issue certificate
sudo certbot certonly --standalone -d yourdomain.com -d www.yourdomain.com

# 3. Restart web server
sudo systemctl start nginx || sudo systemctl start apache2