Allow subdomains to be used for tiles.

index.js

@@ -41,8 +41,8 @@ module.exports = function(options) {
 
     // Add host info middleware.
     var host = require('./server/host')(options);
-    exports.uiServer.use(host);
-    exports.tileServer.use(host);
+    exports.uiServer.use(host.middleware);
+    exports.tileServer.use(host.middleware);
 
     // Bootstrap.
     require('tilestream/server/bootstrap')(options);
@@ -63,6 +63,7 @@ module.exports = function(options) {
                 '--config=PATH': 'Pass options via JSON config file at PATH.',
                 '--uiPort=PORT': 'UI server port. Defaults to 8888.',
                 '--tilePort=PORT': 'Tile server port. Defaults to 8888.',
+                '--subdomains=LIST': 'Comma separated list of subdomains to use for tiles.',
                 '--tiles=PATH': 'Path to tiles directory.'
             },
             command: function(argv, callback) {

server/host.js

@@ -1,16 +1,42 @@
+var _ = require('underscore')._;
+
 // Middleware, retrieves host information from request headers and passes them
 // to the rest of the stack at `req.uiHost` and `req.tileHost`.
 module.exports = function(settings) {
-    return function(req, res, next) {
-        if (req.headers && req.headers.host && !req.uiHost) {
-            req.uiHost = 'http://' + req.headers.host + '/';
-            req.tileHost = ['http://' + req.headers.host + '/'];
-            req.model = req.model || {};
-            req.model.options = req.model.options || {};
-            req.model.options.uiHost = req.uiHost;
-            req.model.options.tileHost = req.tileHost;
-        }
-        next();
+    var host = {
+        removeTileSubdomain: function(host) {
+            // If subdomain already exists on the request host, remove it.
+            var subdomains = settings.subdomains.split(',');
+            var hostComponents = host.split('.');
+            if (_.include(subdomains, hostComponents.shift())) {
+               return hostComponents.join('.');
+            } else {
+                return host;
+            }
+        },
+        middleware: _(function(req, res, next) {
+            if (req.headers && req.headers.host && !req.uiHost) {
+                req.uiHost = 'http://' + req.headers.host + '/';
+                if (settings.subdomains) {
+                    // Add subdomains for tiles.
+                    var basehost = host.removeTileSubdomain(req.headers.host);
+                    var subdomains = settings.subdomains.split(',');
+                    req.tileHost = [];
+                    _.each(subdomains, function(subdomain) {
+                        req.tileHost.push('http://' + subdomain + '.' + basehost + '/');
+                    });
+                } else {
+                    // Use the same host for UI and tiles.
+                    req.tileHost = ['http://' + req.headers.host + '/'];
+                }
+                req.model = req.model || {};
+                req.model.options = req.model.options || {};
+                req.model.options.uiHost = req.uiHost;
+                req.model.options.tileHost = req.tileHost;
+            }
+            next();
+        }).bind(this)
     };
+    return host;
 };