Rails application behind proxy, with SSL, renders paths as "http://"

Question

To start with, this sounds more like a bug then anything else.

My rails application is served by Unicorn. Then, using Nginx as a reverse proxy, I serve the application to the outside world using SSL.

So far so good, no problem. I'm using relative paths (Restful path helpers), so there should be no problem to produce this (for https://www.example.com):

new_entry_path => https://www.example.com/entries/new

This works fine in most cases.

The problem however appears when in a controller I try to redirect to a "show" action (using resources), let's say after a successful update (suppose Entry with id 100):

redirect_to @entry, flash: {success: "Entry has been updated"}

or

redirect_to entry_path(@entry), flash: {success: "Entry has been updated"}

they both produce a redirect to:

http://www.example.com/entries/100 # missing 's' in https...

instead of

/entries/100 # implying https://www.example.com/entries/100

As far as I've noticed, this only happens with show action and only in controller redirects.

I'm bypassing this by doing something horrible and disgusting:

redirect_to entry_url(@entry).sub(/^http\:/,"https:"), flash: {success: "Entry has been updated"}

Has anyone ever confronted something similar? Any ideas will be gratefully accepted...

Answer 1

So far, I've managed to get a workaround by adding a rewrite rule to Nginx, under plain http:

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

Which redirects all plain http requests to the https server.

Update:

Apparently, as I want the app not to care about how the front web server is serving it, it's up to the same web server to "clean the mess" of redirections the app by itself cannot handle unless it's been specifically configured (not desired). So, I will stick to this answer (workaround rather...)

UPDATE
Following papirtiger's answer, I saw that I ended up missing the flashes, which should be added to the overriding redirect_to as a parameter.

But I've found a way to do my life a lot easier, simply by overriding a different function, that is called from within redirect_to.

def _compute_redirect_to_location(options) #:nodoc:
    case options
    # The scheme name consist of a letter followed by any combination of
    # letters, digits, and the plus ("+"), period ("."), or hyphen ("-")
    # characters; and is terminated by a colon (":").
    # See http://tools.ietf.org/html/rfc3986#section-3.1
    # The protocol relative scheme starts with a double slash "//".
    when /\A([a-z][a-z\d\-+\.]*:|\/\/).*/i
        options
    ## WHEN STRING: THIS IS REMOVED TO AVOID ADDING PROTOCOL AND HOST ##
    # when String
    #   request.protocol + request.host_with_port + options
    when :back
        request.headers["Referer"] or raise RedirectBackError
    when Proc
        _compute_redirect_to_location options.call
    else
        url_for(options)
    end.delete("\0\r\n")
end

Thus, without having to change anything else in my code, I have a working relative redirect.