How to ensure www.example.com is redirected to example.com by using Nginx, Gunicorn and Let's Encrypt certificates ?

Hello,

Can you please tr to replace the following server block

    if ($host = www.example.com) {
        return 301 https://$host$request_uri;
    } # managed by Certbot

with

server {
    listen 443 ssl;

    server_name www.example.com;

    rewrite ^/(.*) https://example.com/$1 permanent;
}

and let me know how it goes?

Please remember to restart Nginx after you make the file changes.

Regards, KFSys

Your understanding is correct. The issue is in the Nginx configuration where the redirection from www.example.com to example.com is not explicitly handled. The current configuration only ensures that all HTTP traffic is redirected to HTTPS, but it does not handle the stripping of the www subdomain.

You need to modify the Nginx configuration to include a rule for redirecting www.example.com to example.com. Here’s how you can adjust your configuration:

1. Update the HTTPS Server Block

Modify the server block that handles SSL (port 443) to redirect www.example.com to example.com. Your SSL server block should look like this:

server {
    server_name www.example.com;

    return 301 https://example.com$request_uri;

    listen 443 ssl; # managed by Certbot
    ssl_certificate /etc/letsencrypt/live/example.com/fullchain.pem; # managed by Certbot
    ssl_certificate_key /etc/letsencrypt/live/example.com/privkey.pem; # managed by Certbot
    include /etc/letsencrypt/options-ssl-nginx.conf; # managed by Certbot
    ssl_dhparam /etc/letsencrypt/ssl-dhparams.pem; # managed by Certbot
}

server {
    server_name example.com;

    location / {
        include proxy_params;
        proxy_pass http://unix:/run/exampleproject.sock;
    }

    listen 443 ssl; # managed by Certbot
    ssl_certificate /etc/letsencrypt/live/example.com/fullchain.pem; # managed by Certbot
    ssl_certificate_key /etc/letsencrypt/live/example.com/privkey.pem; # managed by Certbot
    include /etc/letsencrypt/options-ssl-nginx.conf; # managed by Certbot
    ssl_dhparam /etc/letsencrypt/ssl-dhparams.pem; # managed by Certbot
}

2. Update the HTTP Server Block

Modify the server block that handles HTTP (port 80) to redirect all traffic to HTTPS and handle the www to non-www redirection:

server {
    if ($host = www.example.com) {
        return 301 https://example.com$request_uri;
    }

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

    return 301 https://example.com$request_uri; # Redirect all HTTP to HTTPS on non-www
}

3. Check Configuration and Restart Nginx

After making these changes, check your Nginx configuration for syntax errors:

sudo nginx -t

If there are no errors, restart Nginx to apply the changes:

sudo systemctl restart nginx

Explanation:

• The first SSL server block catches requests to www.example.com over HTTPS and redirects them to example.com.
• The second SSL server block handles requests to example.com over HTTPS.
• The HTTP server block redirects all HTTP traffic to HTTPS and handles the www to non-www redirection for HTTP traffic.

With these changes, your Nginx configuration should correctly handle the redirection from www.example.com to example.com while also redirecting all HTTP traffic to HTTPS.