# DO NOT EDIT - This file is being maintained by Chef

upstream tile_cache_backend {
    server 127.0.0.1;
    <% @caches.each do |cache| -%>
    <% if cache[:hostname] != node[:hostname] -%>
    #Server <%= cache[:hostname] %>
    <% cache.ipaddresses(:family => :inet, :role => :external).sort.each do |address| -%>
    server <%= address %> backup;
    <% end -%>
    <% end -%>
    <% end -%>

    keepalive 32;
}

# Rates table based on current cookie value
map $cookie_qos_token $limit_rate_qos {
  include /etc/nginx/conf.d/tile_qos_rates.map;
}

# Set-Cookie table based on current cookie value
map $cookie_qos_token $cookie_qos_token_set {
  include /etc/nginx/conf.d/tile_qos_cookies.map;
}

map $http_user_agent $approved_scraper {
  default '';                       # Not approved
  '~^JOSM\/' 'JOSM';
  '~^Mozilla\/5\.0\ QGIS\/' 'QGIS';
}

# Limit Cache-Control header to only approved User-Agents
map $http_user_agent $limit_http_cache_control {
  default '';                              # Unset Header
  '~^Mozilla\/5\.0\ QGIS\/' '';            # Unset Header
  '~^Mozilla\/5\.0\ ' $http_cache_control; # Pass Header
}

# Limit Pragma header to only approved User-Agents
map $http_user_agent $limit_http_pragma {
  default '';                       # Unset Header
  '~^Mozilla\/5\.0\ QGIS\/' '';     # Unset Header
  '~^Mozilla\/5\.0\ ' $http_pragma; # Pass Header
}

server {
    listen       443 ssl fastopen=2048 http2 default_server;
    server_name  localhost;

    proxy_buffers 8 64k;

    ssl_certificate      /etc/ssl/certs/tile.openstreetmap.org.pem;
    ssl_certificate_key  /etc/ssl/private/tile.openstreetmap.org.key;

    location / {
      proxy_pass http://tile_cache_backend;
      proxy_set_header X-Forwarded-For $remote_addr;
      proxy_http_version 1.1;
      proxy_set_header Connection '';

      proxy_connect_timeout 5s;

      # Do not pass cookies to backends.
      proxy_set_header Cookie '';
      # Do not pass Accept-Encoding to backends.
      proxy_set_header Accept-Encoding '';

      # Do not allow setting cookies from backends due to caching.
      proxy_ignore_headers Set-Cookie;
      proxy_hide_header Set-Cookie;

      # Set a QoS cookie if none presented (uses nginx Map)
      add_header Set-Cookie $cookie_qos_token_set;
<% if node[:ssl][:strict_transport_security] -%>

      # Enable HSTS
      add_header Strict-Transport-Security "<%= node[:ssl][:strict_transport_security] %>" always;
<% end -%>

      # QoS Traffic Rate see $limit_rate on http://nginx.org/en/docs/http/ngx_http_core_module.html
      set $limit_rate $limit_rate_qos;

      # Allow Higher Traffic Rate from Approved User-Agents which do not support cookies (uses nginx Map)
      if ($approved_scraper) {
        set $limit_rate 32768;
      }

      # Strip any ?query parameters from urls
      set $args '';

      # Allow cache purging headers only from select User-Agents (uses nginx Map)
      proxy_set_header Cache-Control $limit_http_cache_control;
      proxy_set_header Pragma $limit_http_pragma;
    }
}