Dealing with nginx 400 “The plain HTTP request was

Question

I'm running a Sinatra app behind passenger/nginx. I'm trying to get it to respond to both http and https calls. The problem is, when both are defined in the server block https calls are responded to normally but http yields a 400 "The plain HTTP request was sent to HTTPS port" error. This is for a static page so I'm guessing Sinatra has nothing to do with this. Any ideas on how to fix this?

Here's the server block:

server {
        listen 80;
        listen 443  ssl;
        server_name localhost;
        root /home/myhome/app/public;
        passenger_enabled on;

        ssl on;
        ssl_certificate      /opt/nginx/ssl_keys/ssl.crt;
        ssl_certificate_key  /opt/nginx/ssl_keys/ssl.key;
        ssl_protocols        SSLv3 TLSv1;
        ssl_ciphers          HIGH:!aNULL:!MD5;

        location /static {
            root  /home/myhome/app/public;
            index  index.html index.htm index.php;
        }

        error_page 404 /404.html;

        # redirect server error pages to the static page /50x.html
        error_page 500 /500.html;

        access_log /home/myhome/app/logs/access.log;
        error_log /home/myhome/app/logs/error.log;
}

Answer 1

I had the exact same issue, I have kind of the same configuration as your exemple and I got it working by removing the line :

ssl on;

To quote the doc:

If HTTP and HTTPS servers are equal, a single server that handles both HTTP and HTTPS requests may be configured by deleting the directive “ssl on” and adding the ssl parameter for *:443 port

Answer 2

The above answers are incorrect in that most over-ride the 'is this connection HTTPS' test to allow serving the pages over http irrespective of connection security.

The secure answer using an error-page on an NGINX specific http 4xx error code to redirect the client to retry the same request to https. (as outlined here https://serverfault.com/questions/338700/redirect-http-mydomain-com12345-to-https-mydomain-com12345-in-nginx )

The OP should use:

server {
  listen        12345;
  server_name   php.myadmin.com;

  root         /var/www/php;

  ssl           on;

  # If they come here using HTTP, bounce them to the correct scheme
  error_page 497 https://$host:$server_port$request_uri;

  [....]
}