From faf7f77d947a16e3ef2afa84c1f89b54f5035b3e Mon Sep 17 00:00:00 2001
From: Grant Slater <git@firefishy.com>
Date: Fri, 30 Dec 2016 17:12:51 +0000
Subject: [PATCH] tilecache: Add first pass nginx QoS

---
 .../templates/default/nginx_tile_ssl.conf.erb | 61 ++++++++++++++++---
 1 file changed, 53 insertions(+), 8 deletions(-)

diff --git a/cookbooks/tilecache/templates/default/nginx_tile_ssl.conf.erb b/cookbooks/tilecache/templates/default/nginx_tile_ssl.conf.erb
index a22391255..14a13a0e7 100644
--- a/cookbooks/tilecache/templates/default/nginx_tile_ssl.conf.erb
+++ b/cookbooks/tilecache/templates/default/nginx_tile_ssl.conf.erb
@@ -12,6 +12,38 @@ upstream tile_cache_backend {
     keepalive 32;
 }
 
+# Rates table based on cookie value
+map $cookie_qos_token $limit_rate_qos {
+  default 8192; # Default Rate
+  "test" 32768; # FIXME - Future TOTP Token
+}
+
+map $cookie_qos_token $cookie_qos_token_set {
+  # Cookie Domain per RFC 6265
+  default 'qos_token=test; Secure; httponly; Max-Age=3600; Domain=tile.openstreetmap.org; Path=/'; # FIXME - Future TOTP Token
+  "test" ''; # Do not Set-Cookie if current is valid
+}
+
+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;
@@ -29,25 +61,38 @@ server {
     ssl_stapling on;
     ssl_dhparam /etc/ssl/certs/dhparam.pem;
     resolver <%= @resolvers.join(" ") %>;
+    resolver_timeout 5s;
 
     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_set_header Connection '';
 
       proxy_connect_timeout 5s;
 
-      # Do not pass cookies to backend.
-      proxy_set_header Cookie "";
-      # Do not pass Accept-Encoding to backend.
-      proxy_set_header Accept-Encoding "";
+      # 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 cached pages.
+      # Do not allow setting cookies from backends due to caching.
       proxy_ignore_headers Set-Cookie;
       proxy_hide_header Set-Cookie;
 
-      # Slow traffic slightly
-      limit_rate 24576;
+      # Set a QoS cookie if none presented (uses nginx Map)
+      add_header Set-Cookie $cookie_qos_token_set;
+
+      # 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 16384;
+      }
+
+      # 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;
     }
 }
-- 
2.39.5