Dealing with nginx 400 “The plain HTTP request was sent to HTTPS port” error

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 h

Answer 1

The error says it all actually. Your configuration tells Nginx to listen on port 80 (HTTP) and use SSL. When you point your browser to http://localhost, it tries to connect via HTTP. Since Nginx expects SSL, it complains with the error.

The workaround is very simple. You need two server sections:

server {
  listen 80;

  // other directives...
}

server {
  listen 443;

  ssl on;
  // SSL directives...

  // other directives...
}

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;

  [....]
}

Answer 3

if use phpmyadmin add: fastcgi_param HTTPS on;

Answer 4

According to wikipedia article on status codes. Nginx has a custom error code when http traffic is sent to https port(error code 497)

And according to nginx docs on error_page, you can define a URI that will be shown for a specific error.
Thus we can create a uri that clients will be sent to when error code 497 is raised.

nginx.conf

#lets assume your IP address is 89.89.89.89 and also 
#that you want nginx to listen on port 7000 and your app is running on port 3000

server {
    listen 7000 ssl;
 
    ssl_certificate /path/to/ssl_certificate.cer;
    ssl_certificate_key /path/to/ssl_certificate_key.key;
    ssl_client_certificate /path/to/ssl_client_certificate.cer;

    error_page 497 301 =307 https://89.89.89.89:7000$request_uri;

    location / {
        proxy_pass http://89.89.89.89:3000/;

        proxy_pass_header Server;
        proxy_set_header Host $http_host;
        proxy_redirect off;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-Protocol $scheme;
    }
}

However if a client makes a request via any other method except a GET, that request will be turned into a GET. Thus to preserve the request method that the client came in via; we use error processing redirects as shown in nginx docs on error_page

And thats why we use the 301 =307 redirect.

Using the nginx.conf file shown here, we are able to have http and https listen in on the same port

Answer 5

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 6

Actually you can do this with:

ssl off; 

This solved my problem in using nginxvhosts; now I am able to use both SSL and plain HTTP. Works even with combined ports.