Nginx reverse-proxy config for many apps

app.conf

include /etc/nginx/conf.d/real-scheme.block;

upstream <app> {
    server 127.0.0.1:<port>;
    keepalive 16;
}

server {
  listen 80;
  server_name <server>;
  access_log /var/log/<app>_access.log;
  location / {
    include /etc/nginx/conf.d/reverse-proxy.block;
    proxy_pass http://<app>;
  }
}

real-scheme.block

# Determine actual scheme (http/https) if available.
# This deals with load-balancer termination of SSL.
map $http_x_forwarded_proto $real_scheme {
  default $http_x_forwarded_proto;
  ''      $scheme;
}

reverse-proxy.block

# Note, $real_scheme relies on ./real-scheme.block

proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header X-Forwarded-Proto $real_scheme;
proxy_set_header Host $http_host;
proxy_set_header Connection ""; # For keepalive
proxy_http_version 1.1;         # For keepalive
proxy_intercept_errors on;
proxy_redirect off;