gistfile1.txt

# This is a nginx config snippet showing how to inherit an http header
# or defaulting it to a specific value. This is useful because it allows
# upstream load balancers to set specific headers, but if they're missing
# the app LB will know how to default it.

# This will inherit the previously set X-Scheme variable, or otherwise 
# default it to the current `$scheme`. Requires nginx 0.9.0+.
#
# Docs: http://wiki.nginx.org/HttpMapModule#map
map $http_x_scheme $x_scheme {
  ""      $scheme;
  default $http_x_scheme;
}

server {
  listen 80;

  # Use the inherited-or-defaulted $x_scheme var
  proxy_set_header X-Scheme $x_scheme;

  # And go to the app server!
  proxy_pass http://frontends;
}