Getting "Too many redirects" error with nginx rewrite rule

Question

I am trying to rewrite the domain url that targets my site such that all domain names are rewritten to www.example.com and have the following config:

mysite block

  server {      
        listen       80 default_server;
        listen   [::]:80 default_server ipv6only=on;

            server_name _;
            rewrite ^ $scheme://www.example.com$request_uri permanent;

    location / {

            # Allow for large file uploads
              client_max_body_size 0;

                proxy_http_version 1.1;
                proxy_pass http://mysite;
                proxy_buffering    off;

                proxy_set_header   X-Real-IP $remote_addr;
                proxy_set_header   X-Scheme $scheme;
                proxy_set_header   X-Forwarded-For $proxy_add_x_forwarded_for;
                proxy_set_header   Host $http_host;
    }
}

The tomcat server block

server {
        listen        80;

        root /opt/site2/www;
        index index.html index.htm;

        # Redirecto root requests to Share
        rewrite ^/$ /share;

        location / {
            # First attempt to serve request as file, then
            # as directory, then fall back to displaying a 404.
            try_files $uri $uri/ /index.html;
        }

        # redirect server error pages to the static page /50x.html
        error_page 502 503 504 /maintenance.html;
            location = /maintenance.html {
            root   /opt/site2/www;
        }

        location /share {

            # Allow for large file uploads
            client_max_body_size 0;

            # Proxy all the requests to Tomcat
            proxy_http_version 1.1;
            #proxy_buffering off;
            proxy_pass http://backend;
            proxy_set_header Host $http_host;
            proxy_set_header X-Real-IP $remote_addr;
            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
            proxy_set_header X-Forwarded-Host $http_host;
            proxy_set_header X-Forwarded-Server $host;
        }

}

in the server block but I am getting a "too many redirects" error.

Solution

Right now any and all requests are going to hit this server block:

server {      
    listen    80 default_server;
    listen    [::]:80 default_server ipv6only=on;

    server_name _; # This doesn't do anything
    rewrite ^ $scheme://www.example.com$request_uri permanent;

    # Rest of file irrelevant
}

Because: no server block has a valid server_name (therefore there will never be host name match) and this is the default_server.

Use appropriate server names

Therefore to always redirect requests hitting the server to a given hostname ensure that there is a server block explicitly for www.example.com:

server {      
    listen    80;
    listen    [::]:80 ipv6only=on;

    server_name www.example.com;

    # Everything else from "Tomcat server block" 
    # or the proxy_pass config as appropriate
}

And redirect requests with any other host name to it:

server {      
    listen    80 default_server;
    listen    [::]:80 default_server ipv6only=on;

    return 301 http://www.example.com$request_uri;

    # Nothing else, because it wouldn't do anything
}

In the above note that return 301 is used as it's considered a better practice than an unconditional rewrite rule.

Comments

[Admin]

Does the site you're redirecting to live on the same server? If so, does it work when you go directly?

[Dark Star1]

Yes they're on the same server and no I get the same error. It's not the complete server block, but I am proxying 2 tomcat apps also.