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

upstream tile_cache_backend {
  server 127.0.0.1;

  # Add the other caches to relieve pressure if local squid failing
  # Balancer: round-robin
<% @caches.each do |cache| -%>
<% if cache[:hostname] != node[:hostname] -%>
<% if node[:tilecache][:tile_siblings].include? cache[:fqdn] -%>
<% cache.ipaddresses(:family => :inet, :role => :external).sort.each do |address| -%>
  server <%= address %> backup; # Server <%= cache[:hostname] %>
<% end -%>
<% end -%>
<% end -%>
<% end -%>

  keepalive 256;
}

# Geo Map of tile caches
geo $tile_cache {
  default 0;
<% @caches.each do |cache| -%>
<% cache.ipaddresses(:family => :inet, :role => :external).sort.each do |address| -%>
  <%= address %> 1; # <%= cache[:hostname] %>
<% end -%>
<% end -%>
}

# 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                   0; # Not approved
  '~^JOSM\/'                1; # JOSM
  '~^Mozilla\/5\.0\ QGIS\/' 1; # QGIS
}

map $http_user_agent $denied_scraper {
  default                0; # Not denied
  ''                     1; # No User-Agent Set
  '~^Python\-urllib\/'   1; # Library Default
  '~^python\-requests\/' 1; # Library Default
  '~^node\-fetch\/'      1; # Library Default
  '~^R$'                 1; # Library Default
  '~^Java\/'             1; # Library Default
  '~^tiles$'             1; # Library Default
  '~^Dalvik\/'           1; # Library Default
  '~^runtastic'          1; # App
  'Mozilla/4.0'          1; # Fake
  'Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1)' 1;  # Fake
}

map $http_referer $denied_referer {
  default                          0; # Not denied
  'http://www.openstreetmap.org/'  1; # Faked
  'http://www.openstreetmap.org'   1; # Faked
  'http://openstreetmap.org/'      1; # Faked
  'http://openstreetmap.org'       1; # Faked
  'http://www.osm.org/'            1; # Faked
  'http://www.osm.org'             1; # Faked
  'http://osm.org/'                1; # Faked
  'http://osm.org'                 1; # Faked
}

# 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 deferred backlog=16384 reuseport 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;

      # Preserve host header.
      proxy_set_header Host $host;
      # 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] -%>
      # Ensure Strict-Transport-Security header is removed from proxied server responses
      proxy_hide_header 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 65536;
      }

      if ($denied_scraper) {
        set $limit_rate 512;
        return 429;
      }
      if ($denied_referer) {
        set $limit_rate 512;
        return 418;
      }

      # 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;
    }
}