example.com redirected you too many times. ERR_TOO_MANY_REDIRECTS

Question

I was trying to Secure Nginx with Let's Encrypt on Ubuntu 16.04.

example.conf file before obtaining an SSL Certificate

server {
    server_name example.com www.example.com ;
    # Tell Nginx and Passenger where your app's 'public' directory is
    root /var/www/backup/mycode/public;
    # Turn on Passenger
    passenger_enabled on;
    rails_env development;
    passenger_ruby /usr/local/rvm/gems/ruby-2.5.6/wrappers/ruby;

}

http://example.com/ is working fine.

I try to Obtain an SSL Certificate by

sudo certbot --nginx -d example.com -d www.example.com

the result was

Your existing certificate has been successfully renewed, and the new certificate
has been installed.

The new certificate covers the following domains: https://example.com and
https://www.example.com

example.conf file after obtaining an SSL Certificate

server {
    server_name example.com www.example.com ;
    # Tell Nginx and Passenger where your app's 'public' directory is
    root /var/www/backup/example.com/public;
    # Turn on Passenger
    passenger_enabled on;
    rails_env development;
    passenger_ruby /usr/local/rvm/gems/ruby-2.5.6/wrappers/ruby;




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


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


    server_name example.com www.example.com ;
    listen 80;
    return 404; # managed by Certbot

}

http://example.com/ is redirecting to https://example.com/ too many times

example.com redirected you too many times.
ERR_TOO_MANY_REDIRECTS

1. Why is it redirecting too many times?

2. what is the purpose of the second server block?

   server {
   if ($host = www.example.com) {
       return 301 https://$host$request_uri;
   } # managed by Certbot
   
   
   if ($host = example.com) {
       return 301 https://$host$request_uri;
   } # managed by Certbot
   
   
   server_name example.com www.example.com ;
   listen 80;
   return 404; # managed by Certbot
   
    }
   

3. How to make all redirects to https://www.example.com/?

EDIT1

Moving the certibot managed code to second server block has stopped the too many redirects problem. But my website is back again directing to HTTP instead of https.

server {
            server_name example.com www.example.com ;
            # Tell Nginx and Passenger where your app's 'public' directory is
            root /var/www/backup/example.com/public;
            # Turn on Passenger
            passenger_enabled on;
            rails_env development;
            passenger_ruby /usr/local/rvm/gems/ruby-2.5.6/wrappers/ruby;

        }
        server {

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


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


            server_name example.com www.example.com ;
            listen 80;
            return 404; # managed by Certbot

        }

Answer 1

what is the purpose of the second server block?

To listen on HTTP and redirect HTTP requests to HTTPS.

Why is it redirecting too many times?

It should not, unless the web site itself doesn't like being called using HTTPS and performs some redirect again. The Nginx config seems to be fine.

How to make all redirects to https://www.example.com/?

Change

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

to

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

You can also add another redirect from https://example.com to https://www.example.com (in the first server block, the one listening on HTTPS); this will take care of redirecting HTTPS requests without "www." at the beginning.

Answer 2

1. Why is it redirecting too many times?

Your application isn't aware if the request came in over SSL or not, adding the following line to your server block should fix it:

passenger_set_header X-Forwarded-Proto $scheme;